From: Marc J. Zeitlin Subject: COZY: Re: Nose gear collapse (fwd) Date: Fri, 2 Jan 98 0:04:38 EST Bruce Elkind writes (or would have, if he had sent it to "cozy_builders@hpwarhw.an.hp.com", instead of me :-) ); >> Today I had a very disappointing incident with my newly built 3-place Cozy: >> on rollout from a normal landing, the nose gear spontaneously retracted, >> scrapping to a noisy halt on the nose structure. After pulling the >> aircraft from the runway and inspecting the damage, I noted that the large >> spur gear in the nose retract mechanisim had lost several teeth. >> Apparently, I had not fully deployed the nose gear, which failed to secure >> the unit against the overcenter lock. >> >> To make the system more secure, is there any problem with creating more >> overcenter action in the nose gear mechanisim, such as by grinding a small >> amount off the retract arms, where they bear against the cross tube? I am >> anxious to incorporate any improvements to this system that the EZ >> community can offer. >> >> Reply with any and all comments, I am eager to learn from others who have >> gone before. -- Marc J. Zeitlin Email: marcz@an.hp.com From: cdenk@ix.netcom.com Date: Fri, 2 Jan 1998 17:26:33 -0600 (CST) Subject: Re: COZY: Re: Nose gear collapse (fwd) On 01/02/98 0:04:38 you wrote: > >Bruce Elkind writes (or would have, if he had sent it to >"cozy_builders@hpwarhw.an.hp.com", instead of me :-) ); > >>> Today I had a very disappointing incident with my newly built 3-place Cozy: >>> on rollout from a normal landing, the nose gear spontaneously retracted, >>> scrapping to a noisy halt on the nose structure. After pulling the >>> aircraft from the runway and inspecting the damage, I noted that the large >>> spur gear in the nose retract mechanisim had lost several teeth. >>> Apparently, I had not fully deployed the nose gear, which failed to secure >>> the unit against the overcenter lock. >>> >>> To make the system more secure, is there any problem with creating more >>> overcenter action in the nose gear mechanisim, such as by grinding a small >>> amount off the retract arms, where they bear against the cross tube? I am >>> anxious to incorporate any improvements to this system that the EZ >>> community can offer. >>> >>> Reply with any and all comments, I am eager to learn from others who have >>> gone before. > >-- >Marc J. Zeitlin Email: marcz@an.hp.com > > Sorry to hear, here are some comments: 1: While you are in the area replace the 3/8" rodends with the magnefluxed high strength ones. The cost should be $25 ea. I had one of the original spec break on landing, with a 737 on short final behind us, he had to go around. 2: My gear was so free running, I added a friction creater to it. A short piece of stainless tubing ( to eliminate wear on the crank tube) riveted to the crank tube just aft of the u-joint. A piece of 1/4" thick nylon plate, drilled and slotted around the tube. A #6 pinch bolt, and a light gage aluminum bracket to allow some misalignment but keep the nylon from turning. Tighten the pinch screw to add some friction. 3: The linkage should go about an 1/8" beyond center, with the gear warning switch adjusted to be less than 1/16" off the stop. I don't see any problem with grinding off the stops, but if you go too far, the result is quickly more force on the stop, due to buckling action. Note the lateral force is related to the tangent of the angle. Note that increasing the past center from 1/8" to 1/4" doubles the lateral force. Date: Mon, 02 Feb 1998 14:25:16 +0200 From: Rego Burger Subject: COZY: Nose - Parking Rubber Not having access to ICE-HOCKEY pucks I looked all over for some suitable rubber for the job. Well minutes ago I walked through my local hardware-store (lunch break) searching the shelves for something similar..there it was, just begging me to buy it. A rubber Sanding Block. High density Rubber..looks like it could do the job. Guess what I'm doing tonight. Maybe someone else could use the tip. Happy Building. Rego Burger, web site: http://home.intekom.com/glen/rnb.htm (home e-mail) mailto:rnb@intekom.co.za Date: Mon, 02 Feb 1998 08:58:18 -0500 From: Tom Teek Subject: Re: COZY: Nose - Parking Rubber Another option is a large rubber mallet available at any hardware store around $3.00 US. Cut it in half and share it with a pal. It is also easy to shape it aerodynamically. Try it---you'll like it. Tom LE- N58AT Date: Mon, 02 Feb 1998 11:05:55 -0500 From: bil kleb Subject: Re: COZY: Nose - Parking Rubber Rego Burger wrote: > > Not having access to ICE-HOCKEY pucks I looked all over for some > suitable rubber for the job. i don't know if you have large semi-trucks running up and down your highways, but ours routinely shed their tires. hockey pucks are meant to slide, not exactly what you want the nose bit for. i think paul k gave me this one... -- bil From: lschuler@cellular.uscc.com Date: Tue, 21 Apr 98 12:46:32 -0600 Subject: COZY: CH-13 NG-30s Plans call for 3 hard points on one NG-30 and 4 on the other for the VENGR . I must be blind as a bat cause I only see 3 shown on the drawing. I believe the drawing is M-10 (I don't have it at hand at the moment). The plans illustrations show two lower points (found those) and two upper points (found only one). The illustrations show the two upper points in a near vertical line and close proximity to one another, while the worm-gear drawings indicate that these two bolt holes would be far from vertical. I do not have the worm gear etc, and may never use one; however, I think it's important to provide for same for the sake of possible future retrofit (ok....back-step). How does one locate the hard-point without a mounting bracket in hand? The M-10 drawing of the mounting bracket only shows 3 bolt attachment points. I perused all the newsletters to see if there had been an update and found none. The archives didn't help either.... how can this be a new issue? I "MUST" be blind! Help!!!!! Larry Schuler lschuler@cellular.uscc.com From: Marc J. Zeitlin Subject: COZY: CH-13 NG-30s Date: Tue, 21 Apr 98 14:39:32 EDT Presumably blind Larry Schuler writes :-): > ..... I must be blind as a bat cause I only see 3 shown on the > drawing. I believe the drawing is M-10 (I don't have it at hand at > the moment). I don't have the drawing, but it could easily be showing only the three common holes. The assumption (not surprisingly) is that you'll be following the plans and will use the NG-51 as a template for laying out and drilling the holes. You can't fault someone for not intuiting that people will use a yet to be invented electric noselift in the future :-). > ...... The illustrations show the two upper > points in a near vertical line and close proximity to one another, > while the worm-gear drawings indicate that these two bolt holes would > be far from vertical. Larry, look closely at the "UP" arrow on the worm-gear drawing - it's parallel to the instrument panel (duh!) - not parallel to the page it's on. The holes are, in fact, vertically (or very close to it) aligned, the way that the VENGR assembly is mounted. > I do not have the worm gear etc, and may never use one; however, I > think it's important to provide for same for the sake of possible > future retrofit (ok....back-step). Good thinking, although the electrical retract mounts in the same holes, so there shouldn't be much of a difference, right? > How does one locate the hard-point without a mounting bracket in hand? Here's the crux of the matter - it seems that you don't. Since, however, all of the electrical retracts that I've ever seen or heard of use the same mounting holes as the standard Brock setup, you should be able to use those as a template for drilling at least the 3 common holes on each side. If you want to provide for the fourth hole, guestimate it's position and just glass in the pad - if you ever install the Brock VENGR, you can drill the fourth hole later. In my estimation, the fourth bolt is superfluous anyway...... if it works with three on one side, it should work with three on the other :-). -- Marc J. Zeitlin Email: marcz@an.hp.com From: lschuler@cellular.uscc.com Date: Tue, 21 Apr 98 16:28:50 -0600 Subject: Re: COZY: CH-13 NG-30s Marc J. Zeitlin kindly wrote: >I don't have the drawing, but it could easily be showing only the three >common holes. The assumption (not surprisingly) is that you'll be >following the plans and will use the NG-51 as a template for laying out >and drilling the holes. You can't fault someone for not intuiting that >people will use a yet to be invented electric noselift in the future :-). Well, yes I can. The plans say to mark the foam using the drawings. Darned hard to do if the drawings are not marked. Frustrating, but not quite as critical as the Canard placement errors I have already had to deal with. Actually, if I remember what I read last night (no guarantees of that either, since I'm both blind and stricken with half-hymers [only remember half of everything these days] :-)) I believe we are instructed to mark the NG-30s via the drawing, drill pilot holes and then make hard points. I don't think we are instructed to use the NG-51 as a drilling template until the holes are drilled. Maybe I'm the first fool to try to do this without the hardware at hand. But, you'd think the drawings would be accurate regardless of my foolishness. >Larry, look closely at the "UP" arrow on the worm-gear drawing - it's >parallel to the instrument panel (duh!) - not parallel to the page it's >on. The holes are, in fact, vertically (or very close to it) aligned, >the way that the VENGR assembly is mounted. Thanks. I'll look at it tonight. That should help turn my WAG into a SWAG location for the hardpoint. Not much to it but 15 plies of BID anyway. I just didn't want to make the pad 10" X 10" in order to cover all bets. If you could give me some semi-accurate (+/- 1/4" is good enough) coordinates from your NG-30 relative to F22 and off a parallel line with F22 to the bottom, I'd appreciate it. I probably won't be digging the foam out till tomorrow night. I'll work on the plywood and Al stuff tonight. >> I do not have the worm gear etc, and may never use one; however, >> I think it's important to provide for same for the sake of >> possible future retrofit (ok....back-step). >Good thinking, although the electrical retract mounts in the same holes, >so there shouldn't be much of a difference, right? Three of the holes, yes. The elusive fourth hole isn't used for electric unit. Plans/drawings have not yet been made available for the hydraulic, steerable, bigger-tire unit which I would prefer (HINT!!) [I'll bet he doesn't see this :-)], so I am stuck with the options currently available. >> How does one locate the hard-point without a mounting bracket in hand? >Here's the crux of the matter - it seems that you don't. Since, >however, all of the electrical retracts that I've ever seen or heard of >use the same mounting holes as the standard Brock setup, you should be >able to use those as a template for drilling at least the 3 common holes >on each side. If you want to provide for the fourth hole, guestimate >it's position and just glass in the pad - if you ever install the Brock >VENGR, you can drill the fourth hole later. Don't have the electric either (yet), but assumed (fatal word) that the three points which are marked on the drawing were fairly close to the required locations. Plan to drill no more than pilot holes until whatever hardware is in hand. >In my estimation, the fourth bolt is superfluous anyway...... if it works >with three on one side, it should work with three on the other :-). That's probably why the electric unit only uses three. Thanks again. Larry Schuler Plans #500 ch-11, 12 mostly done; and moaning about ch-13. lschuler@cellular.uscc.com From: Marc J. Zeitlin Subject: Re: COZY: CH-13 NG-30s Date: Thu, 23 Apr 98 10:35:58 EDT Larry Schuler asked: >If you could give me some semi-accurate (+/- 1/4" is good enough) >coordinates from your NG-30 relative to F22 and off a parallel line with >F22 to the bottom, I'd appreciate it. My measurements show that the fourth hole (the lower one closer to F-22 on the pilot's side of the fuselage) is approximately 4" forward of the rear surface of F-22 at a distance of 2-5/8" from the upper hole. It's NOT directly below the upper hole, but slightly in front of it. If you make a 2-5/8" circle around the upper hole and then intersect it with a line perpendicular to F-22 at 4" from the rear surface, you've got it. Hope this helps. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 23 Apr 1998 09:39:55 -0500 From: Tom Brusehaver Subject: Re: COZY: CH-13 NG-30s >>If you could give me some semi-accurate (+/- 1/4" is good enough) >>coordinates from your NG-30 relative to F22 and off a parallel line with >>F22 to the bottom, I'd appreciate it. I sorta eyeballed things last night, it looks like the drawing on page 3 (chapter 13) is pretty close. From: lschuler@cellular.uscc.com Date: Thu, 23 Apr 98 12:38:27 -0600 Subject: Re[2]: COZY: CH-13 NG-30s Tom Brusehaver wrote: >>If you could give me some semi-accurate (+/- 1/4" is good enough) >>coordinates from your NG-30 relative to F22 and off a parallel line with >>F22 to the bottom, I'd appreciate it. >I sorta eyeballed things last night, it looks like the drawing on >page 3 (chapter 13) is pretty close. Marc Z. Wrote: >My measurements show that the fourth hole (the lower one closer to F-22 on >the pilot's side of the fuselage) is approximately 4" forward of the rear >surface of F-22 at a distance of 2-5/8" from the upper hole. It's NOT >directly below the upper hole, but slightly in front of it. If you make a >2-5/8" circle around the upper hole and then intersect it with a line >perpendicular to F-22 at 4" from the rear surface, you've got it. MUCH thanks to both of you and special to J.D. Found the drawing on ch-13, page 3 is a 'close' match (not exact due to the well known flaws in the large drawings). Simply lay the large drawing under page 3, aligning the bracket bolt holes, then use some carbon paper to mark the missing one; validate with Marc's measurements. Certainly close enough, to make a 'reasonable' guesstimate on location. I'll stick with #38 pilot holes (same as some nail shanks I use for alignment) in all of these for now. I'll use the brackets (whichever flavor) when I get them for final, accurate drilling. Looks like there are only two choices available: Manual worm gear or electric screw jack. Larry Schuler Plans #500 Ch 11-98%; Ch-12 done; starting Ch-13. lschuler@cellular.uscc.com Date: Fri, 24 Apr 1998 15:39:24 +1000 From: Allan Aaron Subject: COZY:Nose Wheel Doors I'm contemplating making up doors for the nose wheel well. I know there is an article in the CSA newsletter with some good information about how to do this, however I have a simple question before I start ...... is there any real benefit in having two doors (ie. split down the center and hinged on both sides) versus just one door hinged on one side only. Comments? From: Howard Calk Subject: RE: COZY:Nose Wheel Doors Date: Fri, 24 Apr 1998 14:30:16 -0400 There are many ways of installing nose wheel doors. I just finished installing nose wheel doors on my Long EZ. I used a combination of the recent CSA newsletter design and another design. The CSA design attached the hinges with bolts into nutplates embedded in vertical sides of the nose wheel hole. A template and a router are used to enlarge the nose wheel hole and form the vertical sides. This design uses a piano wire loop to hold the doors open in the vertical position when the gear is extended and a spring to pull the doors shut. The other design I have attaches the hinges to the bottom skin with flox and some bid. This has to be faired in with micro. This design also uses a spring to pull the doors closed. To hold the doors open, however, it uses a combination of the spring and the airflow between the doors. This is accomplished by making the spring the exact length of the door opening (distance between the two open doors) and making the door opening 1/4" wider at the front than at the rear. (This also means the doors are not rectangular.) This causes the airflow to force the doors open while the spring holds them in the vertical position. Crude and exaggerated ASCII drawing (view w/ fixed font): ___________ \ | / \ | / \__|__/ Doors closed (bottom view) | | |000000000| <-- spring | | Doors open (frontal view) I used the hinge attach method from the CSA design b/c I wanted to be able to remove the doors without having to cut, grind, contour, and paint. I used the spring/airflow method to open, hold open, and close the doors b/c it is simple and EZ. BTW, using the airflow to hold the doors open is a good reason to use two doors rather than one. There may be good designs for a one door system but I haven't seen any. Howard Calk Long EZ builder Date: Fri, 24 Apr 1998 13:37:46 -0500 Subject: Re: COZY:Nose Wheel Doors From: mikefly@juno.com (Michael B Bowden) On Fri, 24 Apr 1998 15:39:24 +1000 Allan Aaron writes: >I'm contemplating making up doors for the nose wheel well. I know >there >is an article in the CSA newsletter with some good information about >how >to do this, however I have a simple question before I start ...... is >there any real benefit in having two doors (ie. split down the center >and hinged on both sides) versus just one door hinged on one side >only. > >Comments? > > A single door may not clear the ground when the nose is down. _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: cdenk@ix.netcom.com Date: Fri, 24 Apr 1998 17:54:27 -0500 (CDT) Subject: Re: COZY:Nose Wheel Doors On 04/24/98 15:39:24 you wrote: > >I'm contemplating making up doors for the nose wheel well. I know there >is an article in the CSA newsletter with some good information about how >to do this, however I have a simple question before I start ...... is >there any real benefit in having two doors (ie. split down the center >and hinged on both sides) versus just one door hinged on one side only. > >Comments? > > > I don't how to make a one sided gear door including the open/close linkage, but it would of course project further away from the bottom of the fuselage which would be more vunerable to damage from air stream. Mine are 2 piece. The hinge pin center is about 1/4" narrower aft to keep the doors open unless the linkage forces them closed Date: Sat, 25 Apr 1998 10:14:19 -0700 From: Wayne Lanza Subject: Re: COZY:Nose Wheel Doors Allan Aaron wrote: > > I'm contemplating making up doors for the nose wheel well. > I have a simple question before I start ...... is there > any benefit in having two doors vs one door. > > Comments? Hi Allan, Sorry you couldn't make it to Sun&Fun, We had a great show again. I spent the week teaching in the electrical/avionics work shop & enjoyed every minute of it! Two things come to mind with one door vs two: * The single door may tend to "flap" in flight due to it's larger area. The two smaller doors can be held open with a small spring loaded assembly and/or with the screen door trick that Vance (& others) use. Making the doors wider in the front i.e. both pointing outward is another tip to keep them open in flight. I can send you (or anyone) the working drawings of my doors (spring assemblies, flush hinges, ...) via post or email for the asking. * The single, wider door may present a clearance problem if you kneel your bird without the gear fully retracted. The small doors are narrow enough such that the front corners will not touch the ground if they are open. Best Wishes, Wayne Lanza From: lschuler@cellular.uscc.com Date: Tue, 09 Jun 98 13:18:06 -0600 Subject: COZY: Chapter 13 Canard Attachement Noted a couple issues with the plans regarding the canard attachment in Chapter 13. Worth repeating if already in the archives. Critical area. I think you all should make note of if you haven't gotten to it yet. Chapter 13, Page 7, last paragraph calls for K1000-4 nutplates; should be MS21047-L4 per change in chapter 12. Same point on drawing M-11. Kinda like modifications; changing one thing changes everything. Same paragraph calls for 0.063" X 3/4" X 1-1/4" aluminum to mount the nut plates on while the drawing calls for AN970-4 washers to mount the nut plates. Not sure which is 'best'. Washers may or may not be wide enough for these nut plates as the only issue. Otherwise the difference is steel vs aluminum. Drawing M-11 shows the canard attach bolts to be AN4-13A. These are probably too short per normal grip range standards. They certainly are if the length of the bushings isn't changed. Consider AN4-14A instead. There should be zero thread inside the bushings when it's all said and done; preferably zero thread in the nut plate retainer as well. Just pay attention when selecting these bolts. Where following the plans to the letter would cause a deviation from standard aircraft practices, one needs to consider the implications of the deviation. The F-22 bushings I received from Brock were .003" over 5/8". Cute. Made for an interesting situation trying to get the bushings to fit without wobbling the holes with a rat tail file. Darn near tossed the bushings in the trash and made my own, but I only had some 1/2" stock for the lathe. Sometimes being a perfectionist is a real pain in the toosh! I'll be measuring everything upon receipt from here on. If it doesn't match the plans, it goes back. It's about the only recourse when dealing with monopolies [Brock]. With the prices he charges you'd think he would be a bit more faithful to the plans. The length of the F-22 bushings turned out to be just a hair long (for my F-22 thickness). The above referenced paragraph says to file the aft ends after floxing in place. Since the glass lay-ups on the back of F-22 are considerably softer than the 2024-T3 bushings, I was afraid of accidentally removing glass as well, or worse, gouging the glass making a weak point. I have decided to lay up one ply of BID over this area to take up the space similar to the BID-shims put on the forward face. My bushings aren't floxed in yet, but noticed a potential for some error in the method described in the plans. Thought I'd point this out FWW. We are instructed (see ref. paragraph) to flox the bushings in with the canard installed along with the AN4 bolts. Unfortunately, doing this without trimming the rear of the bushings "and" installing the nutplates, does not guarantee that the face of the bushings will be flush with the face of F-22. They can easily slide fore-aft along with the canard. Inadvertantly curing in place forward of F-22 would be a bad thing. The lift tabs could be clamped to F-22; but, depending on the trueness of the tab to F-22 mating, this may not be 'best'. Using the BID shims on the rear face will allow me to install the bushings, nutplates and a layer of flox on both front and rear faces of F22 simultaneously and ensure a 'good' fit all around. I'll probably have to be a bit of a contortionist to put the one ply BID over the nutplates with canard in place; but at least I'll sleep better. Larry Schuler MK-IV plans #500 lschuler@cellular.uscc.com From: lschuler@cellular.uscc.com Date: Tue, 09 Jun 98 17:48:56 -0600 Subject: Re: COZY: Brock Whine (Re: Chapter 13 Canard Attachement) Tom Brusehaver wrote: Isn't canard attatch in chapter 12? >snip Yes and no. Chapter 12 title is a bit off. Should be "Canard Fitting". The holes in F-22 along with the bushings and nut plates (final structural attachement stuff) aren't done until chapter 13. Good reason too. Can't do a proper job of drilling F-22 for the bushings until after the 5 plies of BID are done from face of F-22 onto the nose sides. Larry Schuler MK-IV plans #500 lschuler@cellular.uscc.com From: "Marc J. Zeitlin" Subject: COZY: Chapter 13 Canard Attachement Date: Wed, 10 Jun 98 8:49:10 EDT Larry Schuler wrote: >Same paragraph calls for 0.063" X 3/4" X 1-1/4" aluminum to mount the nut >plates on while the drawing calls for AN970-4 washers to mount the nut >plates. Not sure which is 'best'. I used aluminum - worked fine. Easier than steel washers, too, I'd think. > The F-22 bushings I received from Brock were .003" over 5/8". I can't believe I'm actually going to defend Brock here, after all the complaints I've had about them and their (lack of) quality control and customer service, but: I don't think we've seen the plans for the CNL bushings, so we don't know what the tolerance on the 0.625 dimension is. Maybe it's +/- .005, in which case this is per print. I couldn't find the CNL dimensions anywhere. At any rate, since the bushing gets floxed in place with the canard holding it aligned, it doesn't make a lot of difference if the hole in F-22 is a few thousanths oversize. >...... Since the glass lay-ups on the back of F-22 are >considerably softer than the 2024-T3 bushings, I was afraid of accidentally >removing glass as well, or worse, gouging the glass making a weak point. I had the same concern, but if you hold the file evenly with two hands, you (or at least I) can remove the aluminum material without gouging the glass. YMMV, I guess. >...... Unfortunately, doing this without >trimming the rear of the bushings "and" installing the nutplates, does not >guarantee that the face of the bushings will be flush with the face of F-22. > They can easily slide fore-aft along with the canard. While I think that your plan will certainly work, I think you're making more work for yourself than you need to. After floxing the bushings in place and installing the canard, I found no tendency for the canard or the bushings to move at all. Just don't bump into anything. Anyway, I had no problems with the plans method, but there are always more than one way to skin a cat. -- Marc J. Zeitlin Email: marcz@an.hp.com From: lschuler@cellular.uscc.com Date: Wed, 10 Jun 98 13:30:01 -0600 Subject: Re: COZY: Chapter 13 Canard Attachement Marc Zeitlin wrote: >I used aluminum - worked fine. Easier than steel washers, too, I'd >think. Me too. Steel is harder to work with. The issue is a difference between drawing and text. Nat has to fix one of them. >I don't think we've seen the plans for the CNL bushings... I know, there are quite a number of parts that could be made locally, but the specs are not part of our plans or some dimensions are missing from the drawings etc. One way to support a monopoly and ensure kickbacks I guess. May not be intended by the parties involved, but certainly doesn't hurt the beneficiaries. Point well made on returns though. I guess I'd be up the proverbial creek if I wasn't the one who supplied 'my' required specs with 'my' order... I have a small lathe, drill presses, gas and arc welders and so on; all I need is a decent mill and the drawings and I could do all my own parts but the rough castings. My single biggest problem with doing this is "time". Particularly considering that I would probably end up making 4 or 5 parts for each one needed (I'm no pro). Trade is learning/experience gained.... Fair trade. Time is a non-issue. Nat, Care to share the plans for all the metal parts? >...since the bushing gets floxed in place with the canard holding it >aligned, it doesn't make a lot of difference if the hole in F-22 is a >few thousanths oversize. Well, I must agree that making the hole a bit 'bigger' is ok. But the issue was that I used a relatively accurate spot-facing bit (per plans) which resulted in holes that were too 'small' for the bushings (rather than too big). An oversize reamer is rather expensive; especially for a possible one-time use. Alternatives are wobbling them out with the spot facing bit, a regular 5/8" bit, or maybe a file. Or, if one just happens to have a 5/8" wood bit that is a couple thou over, one could very carefully hand-turn the bit (about a half-hour per hole) and still keep the holes fairly square, round, and snug. Not saying which method I used... It's embarassing for a perfectionist like me. :-) >I had the same concern, but if you hold the file evenly with two hands, >you (or at least I) can remove the aluminum material without gouging the >glass. YMMV, I guess. Thanks for the confidence (been-there, done-that) check Marc. Does help. Heck, after turning a wood bit into a hand-held reamer, I figure I wouldn't do much worse with a file on the back of the bushings. After looking this over again last night though, I decided to do the shim layups. The corner tapes from F-22 to fuselage make a small bump near the bushing holes. Using the BID shims will allow me to flox the nutplates in place and not worry about the aluminum being bent by the tape bump when I flox them in. I can sand the area perfectly flat without disturbing the side tapes or F-22's primary structure. >While I think that your plan will certainly work, I think you're >making more work for yourself than you need to. Sounds just like me... mountains 'n mole hills. Doesn't seem to be that much more involved other than adding the simple shim-plies. They could have been done a long time ago when doing other layups (like the front of F-22 shims or any number of other tasks). All the rest (floxing bushings, floxing nut plates, BID over nut plates, flox between F22 and lift tabs) needs to be done anyway; I get to do it all in one session rather than spreading it out over two separate cure-times (3-days each per EZ-10 literature). The only part that may be a bit more difficult will be the BID over the nut plates while the canard is in place. May be the price paid for doing it all at once. Choices. I'm curious. How did you ensure that the lift tabs ended up "tight" against the face of F-22, not just tight against the bushings? Just use some flox (with lift tabs taped) later? Not worry about possible gap? While not having the plans in front of me, I don't remember seeing any provision for this 'possible' gap. I don't think flox is called for as a gap-filler between lift tabs and F-22; but, sure seems like a good idea regardless of how the nut plates and bushings are handled. Larry Schuler MK-IV plans #500 lschuler@cellular.uscc.com From: "Marc J. Zeitlin" Subject: Re: COZY: Chapter 13 Canard Attachement Date: Wed, 10 Jun 98 16:25:03 EDT Larry Schuler wrote; >I'm curious. How did you ensure that the lift tabs ended up "tight" >against the face of F-22, not just tight against the bushings? I installed the bushings with flox, then installed the canard with bolts. I pushed the bushings up tight forward against the lift tabs (which I covered with saran wrap) and then pushed the canard backwards against F-22. This ensured that the lift tab, bushing, and F-22 were all exactly aligned on the front surface. After the flox cured, the canard comes right off and the nutplates went on the back (after filing the bushings to length). Maybe I was just lucky in getting everything right - it didn't seem that complex or worrisome to me (but then, I'm not a worrier :-) ). -- Marc J. Zeitlin Email: marcz@an.hp.com From: "Nat Puffer" Subject: Re: COZY: Chapter 13 Canard Attachement Date: Wed, 10 Jun 1998 19:18:21 -0500 Dear Cozy builders, There is no reason to have tight tolerances on canard lift tab bushings which have to be floxed in place in alignment with the lift tabs. Obviously if the 5/8 inch holes in F-22 are too tight, they must be enlarged to allow for the flox, and to allow for alignment with the tabs. This can easily be done with a round file. Also, the bushings must be supplied long enough so that they can be adjusted to the thickness of each builders F-22, because some builders might have to add additional plies on one side or the other to adjust the canard so it is square with the centerline of the fuselage. The length of the bushings can be adjusted before they are floxed in place. Obviously the bolt call-out is only a guide in selecting the right length bolt. The governing criteria is that the bolt must be long enough so 2 threads extend beyond the nutplate (or nut), but not so long that it runs out of threads. The plans and instructions allow you to rivet the nutplates to either a steel washer or a piece of alumunim. A rectangular piece of aluminum is probably more reliable in securing the nutplate so it will not turn, but if floxed in place and covered with 1 ply BID, either should be acceptable. Where tolerances are critical, for example, the landing gear bushings MKMG-4, the tolerances are shown (see Chap. 9, page 5, Fig. 28). There are many instances where it is not possible to control the fit by establishing tolerances. If a prefab part must fit inside of stock tubing which has a plus or minus 10% wall thickness, it would be better to have that part supplied oversize and adjusted by the builder to fit. If anyone has design questions, we would encourage them to contact us directly. Regards, Nat From: "Nat Puffer" Subject: Re: COZY: Re: 5/8" hole alignment and clearances Date: Fri, 12 Jun 1998 18:51:07 -0500 Thomas, Good suggestion. I made my instrument panel holes undersize, and then found glass jars with tapered sides of the right OD, stuck sandpaper on them and gradually reamed the holes out to the right size. Regards, Nat ---------- From: Thomas Kennedy To: cozy_builders@canard.com Subject: COZY: Re: 5/8" hole alignment and clearances Date: Friday, June 12, 1998 1:32 PM To: In a recent letter Nat writes... if the 5/8 inch holes in F-22 are too tight, they must be enlarged to allow for the flox, and to allow for alignment with the tabs. This can easily be done with a round file... Builder suggestion: For all these 5/8" bored holes that need to be slightly enlarged, I have had very good results by using a long socket the next size down and wrapping it with a length of 100 or 120 grit sand paper to gradually enlarge the hole's diameter. Tom Kennedy, Plans #248 Canard is FINALLY in and done! ALMOST finished with the nose. From: Epplin John A Subject: RE: COZY: Re: 5/8" hole alignment and clearances Date: Sat, 13 Jun 1998 07:46:27 -0600 Regarding the canard bushings. My take on this is the bolt fit is much more important than the bushing to glass fit. I drilled the holes in the mounting tabs to 3/16 when I made them. When I finished the glass work, I took a metal bar and clamped it to the mounting tabs and used a transfer punch to locate the mounting holes. The canard was finished at this time. I then drilled these holes, I don't recall the exact size, 1/4 would be OK. The bar should be as thick as you can find that you can use. I used 1/2 inch aluminum. Using this clamped to F22, I drilled the pilot holes into F22. The thicker bar keeps the holes square to the former. Important to drill the holes in the bar in a drill press. I then opened up the holes with a 5/8 hole saw. I like this better than a spot facer, probably makes no difference. I then made the bushings to fit the holes left by the hole saw. These will almost always be oversize. I made 3/16 holes in the bushings. I then floxed the bushings in place, mounting the canard temporarily with 3/16 bolts, large area washers and plenty of release. I use PLY-9 as a release agent, let it dry before you get it near epoxy. After this it was a simple matter to enlarge the holes with the canard in place from the rear. Drill up in steps to 1/64 undersize then ream to .250. AN bolts are 1.5 to 2 thousands under size so you will have a good fit. I then made and installed the nutplate holders per plans using the aluminum plate method. I had previously checked for canard squarness, turns out mine was as close to perfect as could be hoped for. You should resolve this before the bushings in my opinion. Hope this helps someone. John epplin Mk4 #467 Date: Sat, 13 Jun 1998 22:28:03 -0400 From: David Domeier Subject: Re: COZY: Chapter 13 Canard Attachement Nat, re "The governing criteria is that the bolt must be long enough so 2 threads extend beyond the nutplate (or nut),...." After removing and reinstalling the canard on my LEZ a number of times, I found one of the nut plates to be stripped out. So, in my MKIV, I did not bother with nutplates at all. The canard attach bolts are sucured with wide washers under good old fashioned AN nuts. I am condident the canard will remain attached to F22. dd From: lschuler@cellular.uscc.com Date: Mon, 15 Jun 98 08:58:40 -0600 Subject: Re[2]: COZY: Chapter 13 Canard Attachement Nat Puffer wrote: >There is no reason to have tight tolerances on canard lift tab bushings... >snip I can certainly understand the concept and reasoning here; but, since this is my life and the life of my passengers we are discussing along with other builders, would you please tell me and the rest of us: How tight is "too tight" How much space is required for the flox? How loose is too loose? >Also, the bushings must be supplied long enough so that they can be >adjusted... >snip I don't remember seeing any concerns about the length of the CNL bushings as supplied. Did I miss something? >Obviously the bolt call-out is only a guide in selecting the right length >bolt. The governing criteria is that the bolt must be long enough so 2 >threads extend beyond the nutplate (or nut), but not so long that it runs >out of threads. Sorry, but, personally, I have a problem with two threads beyond the nut being the only criteria. Particularly for shear-stress applications. Maybe I'm all wet, but isn't the "two-threads" the minimum standard for fiber-type locking nuts? At least, that was the only reference I found to any thread length beyond the nut in AC 43.13-1A, dated 1988 which calls for at least 1/32" beyond the nut for flat-ended bolts. AC 43.13-1A, paragraph 227, b states, in part: "In general, bolt-grip lengths should equal the material thickness. However, bolts of slightly greater grip length may be used provided washers are placed under the nut or the bolt head." We should all know that grip length of AN hardware does not include the threads. The reference does not indicate any allowance for threads within the material, or grip lengths shorter than the material thickness. Please feel free to correct my understanding. Two threads on "everything" would sure make things easier. Maybe I missed something? >The plans and instructions allow you to rivet the nutplates to either a >steel washer or a piece of alaluminum. >snip I guess I must take exception to your statement that the plans, as currently written, as supplied to me, and as changed/updated via official newsletter, provide an option to use either aluminum or steel. Again, maybe I missed something, but seems to me the drawing calls for a steel washer and does not show a piece of aluminum as an option; the text specifies a piece of aluminum and does not say a single word about a steel washer as an optional backing. I suppose that if I had written the words and drawn the drawings and knew what I had intended, I might be inclined to say the same as you. Unfortunately your intentions didn't make it through the printing process. I wasn't concerned with which is easier to work with (aluminum or steel), nor which could possibly turn easier (something oblong or something round). My primary concern was a potentially significant structural design disagreement between the text and the drawing and an "OBVIOUS" error in the plans which I believe needs to be corrected for clarification. I take my canard attachment as VERY critical. If I am not allowed to have a bubble of air within 10" of the canard attachment points, then I must consider the strength difference between aluminum and steel in this area to be just as life-threatening. It scares me that anyone, would take this issue lightly. I do not. I understand from Nat's statement that this "option" is now an official change to both the drawing and to the text to allow either, and that it will appear in the next newsletter as such. Thanks for the clarification. I am not a structural, mechanical, nor aeronautical engineer; nor have I ever claimed that I have the capability to do such work. Therefore, I am at the mercy of the designer who has or claims to have those capabilities and qualifications. Some things may be "obvious" to some; but that doesn't automatically make it "obvious" to the rest of us. Nat, With all due respect, I did not take the purchase of plans from you lightly before spending my money and taking a chance with my life and the life of possible passengers based on your salesmanship. I know you are not a structural, mechanical, nor aeronautical engineer; you are a chemical engineer. I knew that before I bought plans. My choice. I pointed out what I perceived as an error in the plans, as I have before (and will continue to do) with the hope that the plans could be made better or easier to follow for those who follow; or, that I can be corrected on my own interpretation. I sincerely hope that you do not have the mind set that the plans are perfect simply because there are (x) number of plans sold, or (x) number of planes flying, or because you followed them once yourself, or all the testing that needs to be done has been done, or that all of the mistakes that were made have already been caught, or that everyone who buys the plans will read them the way you intended. >Snip >If anyone has design questions, we would encourage them to contact us >directly. Why? Is there something improper about posing a question and providing an answer to 200-plus people all at once? This could occure just as easily in a forum tent as here. Maybe a question is simple, especially if it's been asked and answered more than once. I can understand how frustrating that can be (kind of like raising more than one child). Seems to me that answering a design question in this forum would save you a great deal of aggravation. By the way, who is "we" at Co-Z Development? Only person I have ever communicated with at Co-Z Development is you. Who else can we communicate with about design or plans issues at Co-Z Development? Larry Schuler lschuler@cellular.uscc.com From: lschuler@cellular.uscc.com Date: Mon, 15 Jun 98 09:19:51 -0600 Subject: Re[2]: COZY: Re: 5/8" hole alignment and clearances John Epplin wrote: >snip >When I finished the glass work, I took a metal bar and clamped it to >the mounting tabs and used a transfer punch to locate the mounting >holes. >snip I did similar when first drilling my F-22 (not for the enlarged 5/8". Used a block of hard maple drilled on a drill press, then clamped to F-22. Maybe not quite as accurate as your metal solution, but still better than eyeball. Larry Schuler From: "Nat Puffer" Subject: Re: Re[2]: COZY: Chapter 13 Canard Attachement Date: Mon, 15 Jun 1998 12:10:44 -0500 Dear Larry, To flox the bushings in the canard attach bulkhead, there must be room for the flox. I would guess that .001 to .002 clearance would be sufficient. I would say that over .003 would be too loose, although I have never tried to measure the clearance accurately. It should just be a slip fit. I believe (as I remember) the bushings are supplied a little on the long side so they may be adjusted to the length that each individual builder requires. We are using the same bushings as Burt designed for the Long EZ. Drawing M-11 shows the bushing to be the same thickness as F-22. 1/4" AN Bolts have about 3/8" of threads. 1/4" nutplates are about 1/4" thick. Allowing 2 threads to protrude will still not bottom out the threads. Two threads protruding on all bolts is a pretty good rule. I won't argue about 1-1/2 threads, but 3 or more probably means the nut is bottoming out, unless you are using Sensenich propellor bolts, which have longer threads. What we want to avoid is nuts or nutplates where the bolt doesn't go all the way through and might have only 1 or 2 threads engaged. That would be life threatening. I am sorry if the steel washer vs aluminum plate has caused confusion. This is the first time it has come up. Newsletter #62 is at the printers. I will mention this in the next newsletter. In the meantime, either will be satisfactory. "We" is commonly used as the subject in a Corporation. My wife Shirley is vice president and she is pretty good at answering questions. She is a college graduate and pretty knowlegeable about building airplanes, after over 20 years of helping me. Chemical engineering includes courses in mechanical engineering and the same fluid flow as in aeronautical engineering. I did undergraduate work in Aeronautics in the Navy and post graduate work and studies in Aeronautical engineering at the University of Minnesota (Professor Ackerman), 3M and John Hopkins University (Dr. Clauser). This doesn't mean I know everything, but I have learned a lot about airplane building and hopefully can help others. "We" have tried to make our plans and instructions as complete as possible, but obviously there could still be things which need clarification. We are glad you are concerned about safety. We (Shirley and I) are concerned that some builders might not be. Best regards, Nat Date: Thu, 18 Jun 1998 12:52:50 -0400 From: David Domeier Subject: Re: COZY: Chapter 13 Canard Attachement Larry, re "Nat, With all due respect, I did not take the purchase of plans from you lightly before spending my money and taking a chance with my life and the life of possible passengers based on your salesmanship." I think you're getting a little carried away, Larry. In order to provide as safe a flying machine as possible, Nat has spent much time on everything from washers to flight testing. The Cozy MKIV is a safe airplane if built and flown according tothe plan. The carard attach system has been in use for at least 20 years and the only one I ever heard of departing F22 was because the pilot forgot to install the bolts before take off. The carard started flying long befor the airplane did and the take off was aborted. I personally do not like the nut plates. I use plane AN nuts instead. As far as shear strength is concerned, Burt once said at a grass session at OSH, quarter inch bolts have enough shear strength to be used as wing attach bolts, but he knew no one would believe it so we have half inch bolts. The quarter inch bolts screwed tight at the canard attach point with the nut plate or a nut will not come apart. I think the carard will break first. dd From: lschuler@cellular.uscc.com Date: Thu, 18 Jun 98 17:15:22 -0600 Subject: Re[2]: COZY: Chapter 13 Canard Attachement david010@earthlink.net wrote: >snip The Cozy MKIV is a safe airplane if built and flown according tothe plan. >snip I don't think there is a need to belabor the point too terribly much. However, it appears that there is a misunderstanding here. It is rather difficult for us (or at least some of us) to build "per plans" when the plans show two distinctly different things in what some of us might consider a critical area. The entire point was to illustrate this discrepancy and to try to bring reasonable pressure so the plans might be improved. As for the temperament of my message, that is entirely due to other things that have been pointed out as obvious, documented, errors which have not changed in the plans. [Archives are a good place to start.] I think it is appropriate as a member of two groups (the EAA first and a Cozy plans owner second) to try to help those who may follow. I could much more easily, and with less aggravation, just call Nat to ask a question, get my own needs satisfied, and then keep quiet. That, in my opinion, is selfish. Basically all I was doing, was intentionally creating a squeaky wheel. When it appears to me that folks get hard of hearing, I shout louder... :-) Seems that the mission was accomplished. Plans will be improved for all that follow. If there is any suffering due to the exchange, I am sorry, it was not intended. On the other hand, if there was, I pray it may be only an ego and not a life. Larry Schuler MK-IV plans #500 lschuler@cellular.uscc.com Date: Tue, 4 Aug 1998 07:27:07 -0700 Subject: Re: COZY:Brake pedals From: alwick@juno.com (ok How) I made my own Tom. Used cozy plans for them. Gas welded tubing, added appropriate reinforcment to tubing, then powder coated (have to mask certain areas). Made passenger side adjustable, pilot side fits me (I'm 6' 2"). I like building stuff, brake pedals were fun and easy. Cozy plans have enough detail. Milling the slots for the mounting hardware was the most challenging part. If you have access to lathe and mill with rotary table, it's a piece of cake. Many builders (self included) eliminated all the levers & stuff actuating the brakes. I believe there are details in one of the newletters. New sys is very simple. Very pleased with it, no reservations. -al wick 83% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components, now installing winglets. Expect completion date 4-30-99. On Mon, 3 Aug 1998 10:58:48 -0500 Tom Brusehaver writes: >The one thing I wanted to find out at Oshkosh, but didn't was, what >are folks doing with rudder pedals. > >The Brock ones are, expensive, and maybe not all what I want. Not >adjustable on pilot side, but could be modified. > >The AeroCad ones don't have all the fittings to use the brakes as in >the plans. > >My thought now is make my own. I guess if I gotta modify a set, I >might as well make 'em right in the first place. I think I want them >adjustable, I know how tall Nat is, and think I might want my pedals >farther in, but how far? I don't know. Having them adjustable should >allow me to tweak after the plane is done. >I'll listen to any ideas. > _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: N11TE@aol.com Date: Fri, 28 Aug 1998 02:03:57 EDT Subject: Re: [canard-aviators] Re[2]: COZY: Chapter 13 Rudder pedals In a message dated 8/27/98 9:50:11 PM EST, lschuler@cellular.uscc.com writes: << Only one remaining question after this and other responses: One response referred to Vance's plan for the Matco lay-down masters which I intend to use. Anyone have a copy of the CSA page(s) this is on or at least know which newsletter it was in? My fax # is 715-573-7623. >> Oops, I find I gave out bad directions. Obviously first mistake I've made this year (?). The original instructions for the lay-down pedal installation as originally engineered by Vance Atkinson was printed in Nat's Cozy Newsletter #47, page 7, October 1994, not Central States. If you do not have a copy, let me know and I'll fax you one. I modified the design by making an aluminum angle that was glassed in the floor to help hold the forward end of the master cylinder and by using Jeff's idea to make the attachment to the pedals with a piece of aluminum bar stock screwed on the end of the master cylinder sliding inside a piece of 4130 tubing attached to the pedal rather than the milled slots as shown on the drawing. Tom Ellis From: "Brian & Susan DeFord" Subject: COZY: Chapter 13 Rudder pedal alternative Date: Thu, 27 Aug 1998 08:42:08 -0700 I thought I would throw out what I did on my pedals since we have the subject going. I liked the co-pilot adjustable pedals and wanted to have them on the pilot's side as well, so I ordered two sets of co-pilot pedals from Brock instead of one pilot and one co-pilot. Well, Brock sent a pilot/co-pilot set 'cause they figured I didn't know what I was doing, but they gladly sent me what I ordered after I called and explained it to them. They were also a little peaved that they now had an odd ball number of pedals left since they typically sell them in pilot/co-pilot pairs. I need to explain that I am using Matco brakes and Matco lay down cylinders instead of the type Nat shows in the plans and have the cylinders mounted on the floor at the pilot's right pedal and the co-pilot's left pedal. By using identical sets of pedals for both sides, the tabs for the return spring and the rudder cable will be pointing backward. This is actually no problem since the return spring will just get pulled a little longer and the rudder cable will get attached ahead of the pedal instead of behind it (a difference of about 2-1/2 inches in length). Should a person want Now I have identical and adjustable pedal sets for each front seat occupant. Anyone interested in seeing this all in pictures can have a look at my WEB site at chapter 13. By the way, Nat had a look at this set-up when he was inspecting my plane a few months back and liked what he saw. Regards, Brian DeFord From: lschuler@cellular.uscc.com Date: Thu, 27 Aug 98 12:20:45 -0600 Subject: Re: COZY: Chapter 13 Rudder pedal alternative Brian DeFord wrote: >I need to explain that I am using Matco brakes and Matco lay down >cylinders instead of the type Nat shows in the plans and have the >cylinders mounted on the floor at the pilot's right pedal and the >co-pilot's left pedal. Brian, I'd like to use same master cylinders. How did you attach them to the rudder pedals? Add a tab on the front of the pedals? I'd appreciate some rough dimentions of the attachement point(s). Thanks, Larry From: N11TE@aol.com Date: Thu, 27 Aug 1998 14:36:19 EDT Subject: Re: COZY: Chapter 13 Rudder pedal alternative In a message dated 8/27/98 10:47:41 AM EST, bdeford@ionet.net writes: << I thought I would throw out what I did on my pedals since we have the subject going. I liked the copilot adjustable pedals and wanted to have them on the pilot's side as well, so I ordered two sets of copilot pedals from Brock instead of one pilot and one copilot. >> Brian, I also wanted pedals that were adjustable for pilot and copilot. However, I wasn't creative enough to think of ordering two copilot pedals from Brock. Instead, I ordered a set of the pedals specially designed for the AeroCanard from Jeff Russell at AeroCad. These provide for adjustment for both sides, I liked the design better, and they fit both the Cozy and AeroCanard planes. Plus, they were considerably less expensive. Don't think Nat is getting a commission on these like he gets from all Brock parts so that may be one reason. Since there have been some quality questions raised recently about alternate suppliers, I can report (as a builder and an engineer) that the AeroCad pedal assembly I received was of very high quality with first-class welds and more gussets than needed. Much stronger than necessary for the purpose designed for. I have absolutely no concerns about my pedal installation. I orginally installed them using Vance Atkinson's lay-down plans similiar to what you did. Then (to really throw out a new idea guaranteed to attract flames) I kept looking at them and decided I could mount them upside down using pillow blocks located on the forward face of F22 and therefore get rid of the bars going accross the floor. So, I ripped them out and started over. This has resulted in much more foot room! Looked at your web page and found it one of the best and easiest to use that I've seen. Your plane looks great. Tom Ellis N11TE@aol.com Cozy MK IV plans #25 now AeroCanard 540 #11 due to many changes. From: "Steve Campbell" Subject: Re: COZY: Chapter 13 Rudder pedal alternative Date: Thu, 27 Aug 1998 13:46:43 Larry, I am using the brake pedals from Jeff along with the same setup as Brian. The tab is about 2/3'rds of the way up the pedal leg. I'll measure it tonight to get a more exact number. If memory serves, they are attached with a regular AN bolt and nut (The cylinder has a hole in the end that matches the tab hole - I think it fits AN4 hardware, but i'll double check) Steve On Thu, 27 Aug 98 12:20:45 -0600, lschuler@cellular.uscc.com wrote... > >Brian DeFord wrote: > >>I need to explain that I am using Matco brakes and Matco lay down >Brian, >I'd like to use same master cylinders. How did you attach them to the Steve Campbell Professor, ECE University of Minnesota 200 Union Street Minneapolis 55455 Campbell@ece.umn.edu (612) 625-5876 (612) 625-4583 (fax) From: lschuler@cellular.uscc.com Date: Thu, 27 Aug 98 15:24:15 -0600 Subject: Re[2]: COZY: Chapter 13 Rudder pedal alternative Tom Ellis wrote: >...decided I could mount them upside down using pillow blocks located on the >forward face of F22 and therefore get rid of the bars going accross the >floor. So, I ripped them out and started over. This has resulted in much >more foot room! Tom, Neat idea! No flames here. Did you make your own pillow blocks? How'd you mount the master cylinders? Did you use Matco lay-down style? Larry Date: Thu, 27 Aug 1998 16:20:12 -0500 From: Tom Brusehaver Subject: Re: COZY: Chapter 13 Rudder pedal alternative >Neat idea! No flames here. > >Did you make your own pillow blocks? I saw another builders cozy where this was done, he used kydex for the pillow blocks, built the whole thing himself, really looked good. >How'd you mount the master cylinders? Did you use Matco lay-down style? He used the Toyota clutch cylinders like a Velocity. From: N11TE@aol.com Date: Thu, 27 Aug 1998 18:13:27 EDT Subject: Re: Re[2]: COZY: Chapter 13 Rudder pedal alternative In a message dated 8/27/98 3:44:05 PM EST, lschuler@cellular.uscc.com writes: << Tom, Neat idea! No flames here. Did you make your own pillow blocks? How'd you mount the master cylinders? Did you use Matco lay-down style? Larry >> Thanks, Larry, for your nice response. I made the split pillow blocks out of 3/4" thick UMHW (or something like that) plastic. A double block in the middle and single on each side... one close to F22 and one spaced out from F22. I then made some vertical supports up from each side of the NG30's to hold the forward end of the lay-down style master cylinders. Mounted so that they are higher on the forward end to remove air and give proper push angle. I'm using Cleveland lay-down style cylinders but it should be a very similiar mounting for Matco cylinders. Remember that you must space the pedal assembly far enough forward from F22 to still allow the plans directed mounting of the canard tabs against F22. Don't know if this is very clear, but it really was very simple. If you have questions, you are welcome to give me a call @ 812-867-2275. Tom Ellis N11TE@aol.com Cozy MKIV plans #25 now AeroCanard 540 #11 due to all these changes. Date: Thu, 27 Aug 1998 07:59:52 -0400 From: bil kleb Subject: Re: COZY: Chapter 13 Rudder pedals lschuler@cellular.uscc.com wrote: > > Trying to make my own rudder pedals as they generally appear in the > drawings to be fairly simple welded 4130. i made jeff r draw up the pedals that he sells. you should be able to get a copy of them for a price... they are a little sparse on notation however, so you might ask him to jolt down some more notes and dimensions on the drawings if you go that route. -- bil From: N11TE@aol.com Date: Thu, 27 Aug 1998 10:57:43 EDT Subject: Fwd: COZY: Chapter 13 Rudder pedals From: N11TE@aol.com Return-path: To: lschuler@cellular.uscc.com Subject: Re: COZY: Chapter 13 Rudder pedals Date: Thu, 27 Aug 1998 01:41:07 EDT Mime-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit In a message dated 8/26/98 5:59:47 PM EST, lschuler@cellular.uscc.com writes: << 10. Would the use of the lay-down masters be considered a deveiation from the plans which would be significant enough to cause me to name the plane something other than a Cozy since it directly affects safety (ability to stop)? >> As a point of information, Vance Atkinson developed and installed a set of lay-down pedals in his plane which is still being called a "Cozy". He even wrote up a set of plans and instructions which were printed in Central States. You might want to review them as they were quite complete and the design has been in operation for many hours. Tom Ellis N11TE@aol.com Cozy MKIV plans #25 now AeroCanard 540 #11 due to all the changes. From ???@??? Sun Aug 30 16:15:39 1998 Received: from twc2.betaweb.com (betaweb.com [206.43.209.18]) by strato-fe0.ultra.net (8.8.8/ult.n14767) with ESMTP id QAA05637 for ; Thu, 27 Aug 1998 16:52:21 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id QAA32285 for cozy_builders-list; Thu, 27 Aug 1998 16:52:02 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from gatekeep.uscc.com (relay1.uscc.com [205.229.240.3]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id QAA32263; Thu, 27 Aug 1998 16:51:39 -0400 From: lschuler@cellular.uscc.com Received: from cellular.uscc.com (cellular.uscc.com [165.27.237.27]) by gatekeep.uscc.com (8.9.1a/8.9.1) with SMTP id QAA13147; Thu, 27 Aug 1998 16:36:27 -0400 (EDT) Received: from ccMail by cellular.uscc.com (ccMail Link to SMTP R8.00.01) id AA904250539; Thu, 27 Aug 98 15:42:20 -0600 Message-Id: <9808279042.AA904250539@cellular.uscc.com> X-Mailer: ccMail Link to SMTP R8.00.01 Date: Thu, 27 Aug 98 15:41:23 -0600 To: , Subject: Re[2]: COZY: Chapter 13 Rudder pedals MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: lschuler@cellular.uscc.com X-UIDL: 0d7dcbe9fc726db7583646b010437399 Steve Miles wrote: An embarasingly long list of references to pages I didn't look at! Told ya I was an idiot! Oh well, everyone makes mistakes. I'm just not shy about making mine in public so others can learn. Only one remainig question after this and other responses: One response refered to Vance's plan for the Matco lay-down masters which I intend to use. Anyone have a copy of the CSA page(s) this is on or at least know which newsletter it was in? My fax # is 715-573-7623. Most-needed info is the correct positioning of the master cylinder attachement tabs on the rudder pedals, and the location (B.L. & F.S.) of the floor brackets. Thanks for your patience with my mental lapses. Larry Schuler CozyIV plans #500 ______________________________ Reply Separator _________________________________ Subject: Re: COZY: Chapter 13 Rudder pedals Author: at internet Date: 8/26/98 10:29 PM In a message dated 98-08-26 18:59:53 EDT, Larry Schuler wrote: > Questions: > > 1. There are no dimensions for either of these tabs. What are the > dimensions? Reference chapter 13 pages 15 and 16. > 2. There is no definition of the material these tabs are made of. What is > the material? And, how thick is it? .063 4130N steel > 3. How big are the holes in the tabs? Drill #10 > 4. Where are the holes in the tabs relative to the tab edges? Outboard pedals 1.0" from top of pedal, 1.13 from center line of verticle riser facing aft, outboard pedals 5.25" from top of pedals .5" from center of verticle riser facing forward. Distance from edges should be .37" radius, same as for master cylinder brackets. > 5. Are they welded to the pedal vertical sections? Bolted? Welded. > 6. Both tabs appear to be drawn such that they would be perpendicular to > the left edge of each pedal (pointed to the fuselage side rather than fore > or aft). Is this correct? If not what is correct for each one? Offset 6 degrees, outboard pointed aft, inboard pointed forward. > 7. If they are supposed to go fore and/or aft, are they attached to the > left side of the pedal or the fore or aft edge or one of each? Inboard side on inboard pedals, outboard side on outboard pedals. > 8. Is the tab on the pilots left pedal for the rudder and the one on the > passenger's left pedal for a lay-down style master cylinder? Makes sense, > if the pilot's left pedal tab points to the rear and the passenger's left > pedal tab points forward. If the passenger's laft pedal tab is for the > brake, it's size and location are in significant disagreement with the > drawing on page 9; in which case, one of the drwaings is incorrect. Both drawings are correct. The small aft facing tabs on outboard pedals are for rudders, forward facing tabs on inboard pedals are for return springs, large triangular brackets facing forward on pilots side are for master cylinders. > 9. To reduce the complexity of the Rube Goldburg brake linkage, I would > like to use the Matco lay-down style master cylinders. Is the 1-3/4" > verticle dimension for the tab on the passenger's left pedal appropriate? > If not, what is? That is for the rudder pedal return spring, re: figure 38 chapter 13 page 8. Plans version brakes use 2.5". > 10. Would the use of the lay-down masters be considered a deveiation from > the plans which would be significant enough to cause me to name the plane > something other than a Cozy since it directly affects safety (ability to > stop)? Doubtful, but I would ask Nat. > 11. Would making my own rudder pedals rather than paying a rediculous > amount to Brock for some seemingly simple welds cause me to rename the > plane from a Cozy since these directly affect flight (rudders) and safety > on the ground (brakes)? Doubtful, that's why they're drawn in such detail with dimensions and material callouts on pages 15 and 16 chapter 13. > 12. How is Brock able to make these without the complete drawings and > details? I have the drawings and details in my plans. > 13. If Brock has drwawings for any parts used on the Cozy which are more > detailed than the drawings I received, can I get a copy of those as well > please? Check above referenced pages. > 14. If the answers to any of these questions are in the plans would > someone please point that out to me. Sometimes I see stuff that isn't > there and sometimes I can't see my own face in a mirror. Pages 15 and 16 chapter 13. > Thanks, > > Larry Schuler MK-IV Plans #500 HTH, Steve Miles Cozy MkIV 272 From: cdenk@ix.netcom.com Date: Thu, 10 Sep 1998 07:28:39 -0500 (CDT) Subject: Re: COZY: Prop Protection? A. Arron writes < Remove the thread from the Nose tire to minimize picking stones into prop> I was able to remove most of the tread (left about 1/16") with a 10" table saw from a MKIV tire. I used a planer blade, but I think almost any will work. Drilled a 5/16" hole in a foot square piece of 3/4" plywood, and counterbored bottom for bolt head. Used axle bolt with spaces to secure wheel and plywood, yet rotate tire. Clamp plywood to saw table, loosen clamps slightly and hammer sieways for adjustment. Use front part of blade to cut edges, since bottom of grooves is not flat. Without moving plywood turn wheel over and do ather side to keep symmetric. Do several times with different cutting angles to get whole width. Leaves a kind of rough surface, but no different than worn tire. Balance using stick on Mag wheel weights and rod through axle hole on 2 sharp edges. From: lschuler@cellular.uscc.com Date: Wed, 16 Sep 98 09:51:54 -0600 Subject: COZY: Ch-13 rudder pedals Ok, I'm about to have another foot-in-mouth episode; some reason I just can't resist. Got a question I probably already know the answer to, but figured I needed to bounce my thinking off you patient folks in Cozy land. My understanding of acceptable practices in making airplanes includes the need to use castelated nuts and cotter-pins (or similar) on all bolts used where there will be parts rotating around the bolt (particularly control systems). The nose wheel axle bolt is a good example. Self locking hardware is not supposed to be used in these applications as there is still the possibility for the bolt to loosen and fall out. Hope I described that well enough. If that's true, it appears that there is a potential for loss of one or both brakes/rudders during some point in the life-cycle of our airplanes. The plans call for the use of a self-locking nutplate for the rudder pedal pivot bolts. Seems to go against acceptable practices. Please, I don't want to hear that none have failed yet. That ain't good enough. Way too many historical cases of latent failures in airplanes (thus the standards we use these days). Tell me I'm all wet in my understanding of the standard practices though, if that's the case. Larry Schuler MK-IV #500 Ch-13 From: cdenk@ix.netcom.com Date: Wed, 16 Sep 1998 11:35:15 -0500 (CDT) Subject: Re: COZY: Ch-13 rudder pedals - Safetying bolts Another case, get the book "Accepted practices", AND READ IT. If I remember right, if something turns on the assembly, like the bearings, then a cotter or safety wire or lock plate are required. If everything is static, then locking nuts or lock washers are OK. If the self locking nutplates aren't happy by you, use drilled head bolts, and safety wire. From: Epplin John A Subject: RE: COZY: Ch-13 rudder pedals Date: Wed, 16 Sep 1998 12:43:19 -0500 > -----Original Message----- > From: lschuler@cellular.uscc.com [SMTP:lschuler@cellular.uscc.com] > > My understanding of acceptable practices in making airplanes includes the > need to use castelated nuts and cotter-pins (or similar) on all bolts used > > where there will be parts rotating around the bolt (particularly control > systems). [Epplin John A] Thought about this one also. There is a bushing that should not rotate involved here. Better than nothing, but still not the ultimate solution. The only thing that comes to mind that can be done easily is to weld the bushing to a small plate that could be fastened to the airframe in some way that would keep it from rotating. This is still not the ultimate solution, anybody out there have a better idea? The loading placed on the system from rudder use is probably fairly low, the system should stay in place even if the bolt came out. However, the loading from the braking system is another matter. This may cause real problems??? John Epplin Mk4 #467 Date: Wed, 16 Sep 1998 13:50:15 -0400 From: David Domeier Subject: Re: COZY: Ch-13 rudder pedals Larry, re "The plans call for the use of a self-locking nutplate for the rudder pedal pivot bolts. Seems to go against acceptable practices." Understand your consternation....the world isn't perfect....somethings seem and are inconsistent. I have the same problem with attaching the canard to F22. I did not like the nut plate arrangement so I use self locking nuts, is it better, who knows? At least I feel better about a couple 1/4" nuts rather than nut plates. No ones lost a canard yet, either way. dd From: lschuler@cellular.uscc.com Date: Wed, 16 Sep 98 17:49:25 -0600 Subject: Re[2]: COZY: Ch-13 rudder pedals John Epplin wrote: >Thought about this one also.... >... anybody out there have a better >idea? John, I have one that uses bronze bushings (better than steel-on-steel) and no rotation around any bolts. No need to fiddle around with nutplates either. Someone graciously gave me the idea when visiting my project this summer. Don't think I should publish it without his permission. Maybe if I can get his OK and this one works for me, I will work with him to publish it in the CSA. Shoot, maybe it was already published there and I haven't seen it (don't have all back issues). I could get real fancy with this one and use ball or roller bearings, but don't think the wear will be that great to warrant it. Larry Schuler From: lschuler@cellular.uscc.com Date: Wed, 16 Sep 98 18:01:04 -0600 Subject: Re[2]: COZY: Ch-13 rudder pedals Norm Doty wrote: >not a problem, you put a spacer over the bolt so its become a shoulder >bolt and is torqued to the nutplate, the bolt therefore doesn't rotate as >the pedals are used. Hmmmmm. I think I understand the point. However, isn't this kind of like the rod-end ball joints which are bolted to something? The ball generally doesn't move since it's clamped by the bolt to whatever; but, doen't we normally use a castelated nut here also? Same for cable pully bearings? Larry From ???@??? Sun Sep 20 17:59:14 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult.n20340) with ESMTP id XAA09975 for ; Sat, 19 Sep 1998 23:25:08 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id XAA05467 for cozy_builders-list; Sat, 19 Sep 1998 23:32:40 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from arl-img-3.compuserve.com (arl-img-3.compuserve.com [149.174.217.133]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id XAA05462 for ; Sat, 19 Sep 1998 23:32:36 -0400 Received: (from root@localhost) by arl-img-3.compuserve.com (8.8.6/8.8.6/2.14) id XAA03142 for Cozy_Builders@canard.com; Sat, 19 Sep 1998 23:19:01 -0400 (EDT) Date: Sat, 19 Sep 1998 23:18:43 -0400 From: Bill Theeringer Subject: COZY: Mainly rain To: All Message-ID: <199809192318_MC2-5A06-EB9F@compuserve.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by twc2.betaweb.com id XAA05463 Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: Bill Theeringer X-UIDL: 41e1f84fe4bb61b094e1b94c7f3ab6a2 Al and all; When I built my Long EZ I left a hole in the side of the nose that lined up with the nose gear bolt. With a wrench on the nut inside and a socket in the hole I can and do remove the nose gear easily. After painting I took a piece of sail cloth repair material and painted that. This stuff is a tough dacron with a sticky back that looks like a big piece of thick peel ply. I cut out a small round piece and put it over the hole and it stays. Actually kind of difficult to get it off. I also cover up the main wing attach holes with it. Bill Theeringer N29EZ Date: Sun, 20 Sep 1998 01:02:26 -0500 From: Bulent Aliev Subject: Re: COZY: Mainly rain Hi Bill, The cloth you are talking about is: sail repair cloth and you can buy it in the marine stores. Bulent Date: Tue, 29 Sep 1998 17:33:33 -0500 From: Tom Brusehaver Subject: COZY: Cover for nose I have been constructing the cover for the nose (Ch 13), and thought I might ask for suggestions. I was thinking if I made the indentation for the cover lower (less than flush), I might be able to put some weather stripping around the edges. My thoughts is this would be an excellent source for leakage, and some weather stripping might help. Maybe I should ask Mark Beduhn directly, but looking at my pictures from Oshkosh, it looks like his cover is the whole part you cut off. That also might be a way to keep water out, since the openings are at the sides rather than the top, and does seem to simplify the whole construction. Of course everyones covers at Oshkosh seemed different than the plans. Anyone have other advice? From: cdenk@ix.netcom.com Date: Wed, 30 Sep 1998 14:25:23 -0500 (CDT) Subject: Re: COZY: Cover for nose I assume you are talking about the top aft of the canard and forward of the canopy. That is structure and an should be fixed per the plans. Date: Wed, 30 Sep 1998 14:27:56 -0500 From: Tom Brusehaver Subject: Re: COZY: Cover for nose >I assume you are talking about the top aft of the canard and forward >of the canopy. That is structure and an should be fixed per the plans. Nope, I am talking about the access door to the front, brakes, and rudder pedals. From: cdenk@ix.netcom.com Date: Wed, 30 Sep 1998 14:41:46 -0500 (CDT) Subject: Re: COZY: Cover for nose On 09/30/98 14:27:56 you wrote: > > >>I assume you are talking about the top aft of the canard and forward >>of the canopy. That is structure and an should be fixed per the plans. > >Nope, I am talking about the access door to the front, brakes, and >rudder pedals. > > Ok, mine is hinged in the front, has a spring loaded pin aft. The pin is pulled by a bowden cable, with a small lever locqted just forward of the instrument panel accessible from either side when the canopy is open. The cover is weatherstripped and does not leak. Ask if more info wanted. Is most useful when airframe tends to roll on sloped ramp. Am able to activate parking valve, open door, and pull both brake pedals to set brakes. From: mbeduhn@juno.com Date: Wed, 30 Sep 1998 20:23:53 -0500 Subject: Re: COZY: Cover for nose On Tue, 29 Sep 1998 17:33:33 -0500 Tom Brusehaver writes: > >I have been constructing the cover for the nose (Ch 13), and thought I >might ask for suggestions. > >I was thinking if I made the indentation for the cover lower (less >than flush), I might be able to put some weather stripping around the >edges. My thoughts is this would be an excellent source for leakage, >and some weather stripping might help. > >Maybe I should ask Mark Beduhn directly, but looking at my pictures >from Oshkosh, it looks like his cover is the whole part you cut off. >That also might be a way to keep water out, since the openings are at >the sides rather than the top, and does seem to simplify the whole >construction. > Actually, installing the hatch the way I did was not as simple as it looks. There are 4 dowels (2 in front and 2 on each side) that hold the hatch rigidly in position. There are also two screws that hold it down. I also lapped 2 layers of glass from the top of the cover on to the fuselage sides to ensure that it would be water tight. The main reason that I did the hatch this way was for access. With the instrument cover removed, the canard removed and the hatch removed I have great access. However, the nose is not as strong as the plans build version (which I found up on my one obligitory gear up landing). Repairs were easy though and I was flying again in a couple of days. All things considered, if I had to do it over I would build the hatch according to the plans. Mark Beduhn ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: FLYCOZY@aol.com Date: Thu, 8 Oct 1998 12:06:57 EDT Subject: COZY: improved rudder peddals for sale I recently built what I believe is a better set of rudder peddals for the Cozy, Cozy Mark IV and long EZ. The Set which consist of 2 peddals to be mounted on either sides of the ng 30 plates with the master cylinders at about a 30 degress angle. This configuration which is shown in the cozy newsletter 24-5 in detail. The peddals I have for sale, are really nice they were welded by a certified welder , made of 4130 steel and powdercoated. I am buildind a markIV and am using the Cleveland 199-133 super heavy duty brakes. I sent the master cylinders back to wicks that came with the brake kit and ordered the CWB 10-54 master cylinders and A-600 reservoirs. The instalation came out neat and less clutter from extra brackets. I also had the sliders that go on the end of the master cylinders machined to get the desired amount of travel at the wing tip. And am including them with the rudder/ brake peddals. I am offering this set to the first caller for $ 300.00. This is less than the competition and their adjustable on both pilot and co-pilot side. Call me at ( 319 ) 234-6109 or E-mail at FLYCOZY @ AOL.COM Dennis Oelmann N261DM N66DK co builder N2269H co builder From: "astrong" Subject: Re: COZY: Landing lights Date: Mon, 19 Oct 1998 06:35:17 -0700 Guy. Check out "Landing Lights" in Innovations,My homepage it may help. Alex ---------- From: guy Terren To: cozy_builders@canard.com Subject: COZY: Landing lights Date: Sunday, October 18, 1998 11:44 PM Hi All, I am in the process of fixing landing lights in the nose. Has anyone data about the angle required between the axle of the landing lights and level ?. Thanks Guy From: cdenk@ix.netcom.com Date: Mon, 19 Oct 1998 06:51:48 -0500 (CDT) Subject: Re: COZY: Landing lights Terran writes Mine are adjustable, with one fixed point and 2 springloaded screws in fore/ aft direction for aimimg. They should be roughly horizontal, but its trial and error. Probably depends also on the beam of the lamps. I have the Whelan retangular recognition lights, one narrow beam, one wide beam. Date: Thu, 29 Oct 1998 06:24:24 -0500 From: "Jeff S. Russell (http://www.AeroCad.com)" Subject: Re: COZY: Improved rudder pedals Nat Puffer wrote: > > All Cozy Builders, > On October 8, Dennis Oelmann posted a notice that he had designed and built > an improved set of heavy duty rudder pedals for the Cozy III and Mark IV. > They were designed to use the "laydown" CWB 10-54 aerobatic master brake > cylinders similar to the schematic we published in January 1989 Cozy > Newsletter #24-5, and republished in newsletter #47-7. They are stronger > than the pedals we show in the plans, because they are made of 5/8" x 5/8" > x .062 W 4130 square stock, they are FULLY ADJUSTABLE ON BOTH SIDES, and > are flame epoxy coated. Dennis includes the sliders that mount on the > master cylinders to provide the correct amount of rudder travel before > braking. They result in a very neat installation. We asked Dennis to send > us a set, which he did. They are very strong, very well made, and we have > approved them. We will announce in the next newsletter that he is an > "authorized supplier" of these pedals. Dennis will sell them at his cost > plus a little for his time. They will probably cost no more than the plans > pedals from Brock. Dennis is a good friend, a very good builder, and very > honest and trust worthy. We are very pleased to recommend him. You can > reach him at (319) 234-6109 or e-mail at FLYCOZY@AOL.com. These are the same rudder pedels that we have made for years. We gave Dennis a drawing to do this. -- Jeff Russell/AeroCad Inc. E-mail: Jeff@aerocad.com 2954 Curtis King Blvd. Ft. Pierce, FL. 34946 Shop# 561-460-8020 7:00am to 3:30pm Home# 561-334-6200 Website: http://www.Aerocad.com Composite workshop info: http://www.Sportair.com From: "Nat Puffer" Subject: Re: COZY: Improved rudder pedals Date: Thu, 29 Oct 1998 09:17:08 -0600 Dear Tom, I intend to republish in the next newsletter the schematic for rudder pedals using the lay-down aerobatic master brake cylinders that I first published in 1989, and also Dennis' pedal design, in case any builders wish to make them themselves. The pedals Dennis is making are so rugged, so complete, and so nice, and result in such a neat installation, I thought it was too important to wait until the next newsletter. They are an improvement over anything that has been available up until now, and an excellent value for the money. Believe me, I have seen them. Best regards, Nat ---------- > From: Tom Brusehaver > To: cozy@extremezone.com > Subject: Re: COZY: Improved rudder pedals > Date: Wednesday, October 28, 1998 4:19 PM > > > >On October 8, Dennis Oelmann posted a notice that he had designed and built > >an improved set of heavy duty rudder pedals for the Cozy III and Mark IV. > >They were designed to use the "laydown" CWB 10-54 aerobatic master brake > >cylinders similar to the schematic we published in January 1989 Cozy > >Newsletter #24-5, and republished in newsletter #47-7. They are stronger > >than the pedals we show in the plans, because they are made of 5/8" x 5/8" > > Nat, > > If you have space, could you reprint that schematic (in the next > newsletter). I have second edition plans (642 or something like > that), and the newsletters start after 47. > > Thanks From: lschuler@cellular.uscc.com Date: Wed, 04 Nov 1998 16:09:47 -0600 Subject: COZY: Brake Fluid Reserviour Trying to decide whether to use one common brake fluid reservoir or two separate (one each main). Single, common seams to make some sense without giving up safety issue. If it runs dry, I lose both brakes and go straight ahead. If I use separates and run one dry, I do a doughnut on touch down. Thoughts? Larry Schuler Date: Wed, 4 Nov 1998 17:31:22 -0600 From: Tom Brusehaver Subject: Re: COZY: Brake Fluid Reserviour >Single, common seams to make some sense without giving up safety issue. If >it runs dry, I lose both brakes and go straight ahead. If I use separates >and run one dry, I do a doughnut on touch down. > >Thoughts? I guess I would want some brakes, even if I could only go in circles. 80kts on a hard runway would be really scarey with no brakes. You shouldn't land with your feet on the brakes (oof! really short tire life), and sure, let the speed bleed down using aerodynamic forces. I could see a single one for convenience. From: cdenk@ix.netcom.com Date: Wed, 4 Nov 1998 18:38:00 -0600 (CST) Subject: Re: COZY: Brake Fluid Reserviour In real live takeoffs and landings with an EZ, the rudders are NOT decently effective below around 50K. Crosswinds cause the Bird to weathercock into the wind. BOth brakes are really needed, in actuality, if a brake fails, it probably would be noticed when you need it most since its not likely that you use a brake just to test it, except at low speed taxi and runup. The saving grace is raise the nose gear, which will stop you from landing speeds in 300 ft. with minimal damage. Its important to take that large step early while centered on the runway. The minimal damage doesn't count when going through a ditch or taking out a runway light, sign, or a Gulfstream IV. Date: Wed, 04 Nov 1998 18:36:41 -0600 From: vance atkinson Subject: COZY: brake resevoir You should have two reservoirs. One for each brake. One brake is better than none. Here is a typical scenario (it happened to me). You are just landing, your left (or right) brake line just blew out from the main assembly you lose all the fluid in that side. The aircraft momentarily swerves, but let up on both brakes. At this speed you've still got rudder authority. you quickly realize you need to get closer to the failed brake side of the runway (Being and ace pilot you landed in the center). As you deflect the left rudder to steer you over, you also tap the right brake, slowing you down. If you have enough runway left you'll be able to stop at the end doing a right hand swerve or circle. Some fun ! If you are landing on a shorter type strip, add power and go around to a longer and wider one. Vance Atkinson From: cdenk@ix.netcom.com Date: Wed, 4 Nov 1998 18:50:28 -0600 (CST) Subject: Re: COZY: Brake Fluid Reserviour On 11/04/98 16:09:47 you wrote: > >Trying to decide whether to use one common brake fluid reservoir or two >separate (one each main). > >Single, common seams to make some sense without giving up safety issue. If >it runs dry, I lose both brakes and go straight ahead. If I use separates >and run one dry, I do a doughnut on touch down. > Even if the reservoir goes dry to both at the same time, its not likely that you would loose both at the same time. Usually when one of 2 reservoirs gets low, you will notice one pedal being softer or go futher distance as a warning. I fill my reservoirs about 4 time a year. Most of the fluid goes when the pads wear and the pistons project out more. From: "Brown, Michael" Subject: RE: COZY: brake reservoir Date: Wed, 4 Nov 1998 18:17:00 -0700 Ditto Vance's observation - this actually happened to me on the way to Oshkosh this year. Due to a leaking fitting, one brake faded upon touchdown. This is immediately obvious and I followed the same procedure Vance described, with good results. Really the only problem is you have to get out and push your airplane off the runway because you can't taxi with only one brake. Mike Brown N97PZ ---------- From: vance atkinson Subject: COZY: brake reservoir You should have two reservoirs. One for each brake. One brake is better than none. Here is a typical scenario (it happened to me). You are just landing, your left (or right) brake line just blew out from the main assembly you lose all the fluid in that side. The aircraft momentarily swerves, but let up on both brakes. At this speed you've still got rudder authority. you quickly realize you need to get closer to the failed brake side of the runway (Being and ace pilot you landed in the center). As you deflect the left rudder to steer you over, you also tap the right brake, slowing you down. If you have enough runway left you'll be able to stop at the end doing a right hand swerve or circle. Some fun ! If you are landing on a shorter type strip, add power and go around to a longer and wider one. Vance Atkinson Date: Wed, 4 Nov 1998 19:16:38 -0600 Subject: Re: COZY: Brake Fluid Reservoir From: mikefly@juno.com (Michael B Bowden) On Wed, 04 Nov 1998 16:09:47 -0600 lschuler@cellular.uscc.com writes: >Trying to decide whether to use one common brake fluid reservoir or >two >separate (one each main). I originally built the plans brake system for my Long EZ , but converted to front mounted brake cylinders after seeing the neat system in the Berkut prototype. They had "lay-down" type cylinders with slides to actuate brakes at the end of the rudder travel. The cylinders each had a small reservoir mounted with pipe fittings directly on top. I duplicated their system as best as I could from memory and it turned out well although it hasn't been fully tested since I haven't flown yet. The system was in place and full of fluid during a prolonged inverted period in the shop. Some fluid drained out the vents during this time and when turned upright I found little fluid left in one of the reservoirs. I began to think they were too small. Not wanting to start over, I added a large remote reservoir by replacing the vent/fill plugs with pipe fittings that had tube fittings on one end and plumbed plastic tubing to the main reservoir. What this all boils down to, is that I now have both separate and common reservoirs. The main has a sight gauge. If it depletes for some reason, the two reservoirs on the master cylinders will still have enough for stopping unless there is a major leak down stream of the master cylinders. ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] From: cdenk@ix.netcom.com Date: Fri, 6 Nov 1998 07:40:07 -0600 (CST) Subject: Re: COZY: Nose gear collapses On 11/06/98 07:17:29 you wrote: > >Being just about to start on the nose, all this talk of nose gear collapses >is scaring me. > >Is the plans gear mechanism REALLY up to the job? Does it need >beefing-up/over-sizing? >What're other alternatives folks have used? I was thinking of a hydraulic >device with a "free-drop back up. > >d. >Thx >Neil > > No the mechanism seems to be adequate, with 3 exceptions. I have not heard of any other problems. All of the problems are easily corrected: 1: The 3/8" rod ends should be changed to high strength magnafluxed variety. 2: Some of the worm gear assemblies exhibit not enough friction. I have added a friction device to add some friction. Apparently with low friction, and on rough (rolling) surfaces, its possible to jar the past center spring strut off its stop, and once past center to the going up side, the gear retracts! Some have installed a ratchet, but they have been known to fail, and then can't deploy the gear. 3: If original installation does not go past center far enough, then the possiblilty of an uncommanded retract is increased. There are several electric retracts available. They all are heavy, at a location that is much less than ideal, and add complexity. They are very neat for people with spine problems. There have been some failures, and most of the units really don't have more than low to mid time on them, where fatique issues have had the opportunity to become evident. I use the manual crank, and find its easy, and no good reason to do something more expensive, heavy, and less than "Keep it Simple". I thing your getting the wrong impression from the conversation. I use 1900 lbs gross as max. weight and have done more than 1 or 2 carrier landings at near that weight with no ill effects to the Airframe. The message is all aircraft have the possibility of brake failure, especially if you don't do routine inspections of fluid and linings, in particular if you use certified brakes, and have used care in running the tubing, that risk hould be identical, if not less, since it takes less than a hours time to do a complete inspection of the system say 3 or 4 times a year. IF you do have a brake failure, there is an emergency BACKUP, retract the gear, with minimal damage. A big advantage of othe aircraft. For those with main gear retracts, is it possible to retract only the nose gear???? Date: Fri, 6 Nov 1998 09:10:55 -0500 From: Bill Theeringer Subject: COZY: Nose gear collapses For those with main gear retracts, is it possible to retract only the nose gear???? I'm sure JD will respond to this, but yes. My main retractable system is an electric driven hydraulic pump with a CO2 bottle for backup. My nose gear is, and I think I have posted this before, a Black & Decker cordless electric screw driver with the batteries removed. It runs on the 12 volt aircraft system and depends on the built in adjustable slip clutch to engage at the end of the travel limits. Actuation time is about 2 - 3 seconds and it has been in there since 1992. I guess it weighs about 8 ounces and is easily removable because it engages with its hex drive head. Bill Theeringer N29EZ See our award winning Long EZ with Jim Newmans excellent retractable gear at http://www.flash.net/~infaero/infgear.htm Composite Aircraft Accessories HOME: 805-964-5454, SHOP: 805-964-5453 E Mail: Composite_Aircraft_Accessories@Compuserve.com PO Box 21645 Santa Barbara, CA 93121 "Once you have tasted flight, you will walk with your eyes turned skywards, for there you have been, and there you will long to be" Leonardo DaVinci (1452-1519) From: "John R. Rogers" Subject: Re: COZY: Nose gear collapses Date: Fri, 6 Nov 1998 08:19:20 -0600 Doesn't Nat use an electric retract? Wouldn't you agree he is VERY conservative in the "Keep it simple" philosophy? > There are several electric retracts available. They all are heavy, at a > location that is much less than ideal, and add complexity. They are very neat > for people with spine problems. There have been some failures, and most of the > units really don't have more than low to mid time on them, where fatique > issues have had the opportunity to become evident. I use the manual crank, and > find its easy, and no good reason to do something more expensive, heavy, and > less than "Keep it Simple". From: cdenk@ix.netcom.com Date: Fri, 6 Nov 1998 08:40:40 -0600 (CST) Subject: Re: COZY: Nose gear collapses JOhn Rogers writes I don't know what Nat has at this time. The conservatism is only from lack of long term flight experience, and the possiblility of fatique issues of the details. I am a Structural Engineer, and recently at work had to investigate a 5 ton door support failure, that was performing well for 20 years, and then failed causing a fatality! In landing gear and other items, we SHOULD NEVER see a fatique failure. My view at this time for my aircraft, is the manual system does an excellent job, is simple, and light weight. What other criteria would you like to judge by? I am not a grandstander of items that don't meet 1: Safety, 2: Practical (weight), AND 3: Simple. I believe there is a way to electrify the nose gear, without resorting to the heavy worm screw units, just haven't had the time priority to address the issue. Date: Fri, 06 Nov 1998 12:31:34 -0800 From: "LCDR James D. Newman" Subject: Re: COZY: Nose gear collapses Hi Carl and All, > Carl Denk wrote: > For those with main gear retracts, is it possible to retract only the nose gear???? Yes. This is standard. Infinity's Forever, JD Date: Fri, 6 Nov 1998 22:09:23 -0500 From: Bill Theeringer Subject: COZY: Retractable nose gear Bill; YOur Nose gear sounds interesting. Does the hex then engage directly with the usual worm gear shaft?, What is your backup on the nose? Carl; Yes. I cut off a #2 phillips bit and inserted it into the cut off NG-61(tight fit), drilled and pinned it, leaving the hex head to do the engaging. The motor sits on top of the nose wheel blister secured with a single aluminum Adel clamp. You can really tell when the slip clutch engages as the blister reverbs like a drum surface. If your deaf at the end of a long flight, you can also feel it. I was hoping you (and Howard) wouldn't ask that other question. Bill Theeringer N29EZ Date: Sat, 07 Nov 1998 14:52:37 -0500 From: David Domeier Subject: Re: COZY: Nose gear collapses Neal, The nose gear system as designed is OK...it's us dummy pilots who forget to crank it down or try to taxi with it partially extended and strip out the gears that needs watching. The electric system prevents the the later but not the former. dd From: "terren" Subject: COZY: Lexan Date: Sun, 8 Nov 1998 09:43:50 +0100 Hi all, Just some news from my lexan bending. I took a plaster mold from the nose, put it at 150C, put lexan on which slightly bend upon the mold, and then press it against the mold with the Nose. Work fine, i've now formed materials to carve Zeitlin's eyes. Thanks to those who helps me. Guy From: cdenk@ix.netcom.com Date: Fri, 20 Nov 1998 08:09:29 -0600 (CST) Subject: COZY: MKIV NG15 Nose gear casting cracked The night before, while taxiing out do do my 3 night landings, and going over some smooth grass (2' slope down 6 inches then level) the MKNG15(A) casting on the bottom end of the nose strut cracked and came off. Fortunately I was at very low speed, and not landing or taking off, and additional damage was very minimal to the strut fairing. The aircraft has 670 hours on it, and is nose heavy, and operated frequently at 1900 lbs gross with maximum forward C.G. Everyone should as part of the preflight, inspect the MKNG15 for cracks along the top edge of the casting. The initial failure was the left bolt cracking, pealing the right side parallel to the strut. There is evidence of long term cracks on both sides of 1/4" on the right side, and the whole top left ear being broken clear through for some time. I will have a Zip file of JPG files available for those that are able to handle, just ask. Terry Schubert is going to stop by this weekend and get photos for the CSA newsletter. I have talked to Nat, and he is intrested in my comments on changes needed, and I will followup on that. I have talked to Mike and Irene at Brock. They want $200 for a replacement. I have decided to weld up a 4130 steel replacement, and have on Autocad the dimensions, and most of the materials located locally. Will keep posted. Date: Fri, 20 Nov 1998 13:17:13 -0500 From: bil kleb Subject: Re: COZY: Nose wheel > Darcy & Karen Reed wrote: > > I have just received the A-1230 nose wheel from Aircraft Spruce > and after I pulled it out and started inspecting it I began to > wonder is it suppose to be so rough? i just received mine from wicks a few weeks ago, mine is "kinda" rough, but not as bad you describe. (i'll have some photos after the current roll comes out of the camera.) for instance, not all surfaces are machined, but the important ones are. the through-bolt holes are drilled slightly offset from the center of the machined spots, but nothing critical. the hardware supplied (bolts, nuts, etc.) all fit fine. -- bil Date: Sat, 21 Nov 1998 20:30:18 +0200 From: C van Hoof Subject: COZY: Re: MKIV NG15 Nose gear casting cracked Hi Carl & others We witnessed a similar breakage, but not at slow speed. At our 1997 Sun'n Fun Groblersdal meeting, Dave O'Neil's longEze did a normal landing, but when the nosewheel touched down it broke the casting, the amazing thing was that the a/c kept the landing configuration (but now without the wheel). Of course, Dave had to get out and pull it off the tar runway ... all this on video, but unfortunately of _very_ poor quality ... The casting was of the older units - his Eze is over 10 yrs old. if you want more info, i can ask... chris Cozy Mk IV #219 still building... Date: Mon, 23 Nov 1998 13:45:25 -0500 From: bil kleb Subject: Re: COZY: MKIV NG15 Nose gear casting cracked cdenk@ix.netcom.com wrote: > > I will have a Zip file of JPG files available for those that are > able to handle, just ask. i asked carl, and i have put the photos online at: http://www.geocities.com/~kleb/homebuilt/other.html -- bil Date: Mon, 23 Nov 1998 14:56:30 -0500 From: bil kleb Subject: Re: COZY: Nose wheel bil kleb wrote: > > i just received mine from wicks a few weeks ago, mine is "kinda" > rough, but not as bad you describe. (i'll have some photos after > the current roll comes out of the camera.) not particularly great photos, but hey... http://www.geocities.com/~kleb/homebuilt/ch13/ the left-most bolt in `mkng15ntire2.jpg' shows how the through-bolt holes are offset from the center of the machined surfaces. -- bil From: cdenk@ix.netcom.com Date: Wed, 25 Nov 1998 06:56:50 -0600 (CST) Subject: Re: COZY: Nose gear lift device On 11/25/98 11:02:14 you wrote: > >Canardians, >I?m looking for the best ELECTRIC / MANUAL NOSE GEAR LIFT DEVICE >available today on the Canard market, >Can someone suggest me the right one??? >E-MAIL ? FAX NUMBER ? DIRECTION ? > >COSY CLASSIC (3 place) I-COSI reserved > >Every info is welcome, thanks > >Massimo Bonicelli > > > > I prefer the manual, it is very proven, light weight and is simple, easy to use. The Ez's are not a bird that can stand extra weight in particular forward. Someone recently wrote me, using an electric screwdriver motor directly on the worm shaft. It was lightweight, and relatively light weight. Disadvantage, no manual way to get the gear down. I think an easy improvement would be offset the motor to the side with gears or cogbelt drive (there are minatures readily available), leaving a removable crank available. The electric using the linear accuators (Steve Wright most notable) are neat, but add 12 lbs. to the nose weight. If you have a disability (bad back) this is a big advantage, but will add considerably to your takeoff/landing distance. At this point I'm a little conservative, the linear accuators do not have many landings on them, and remember I'm the one that had the nose caster casting break a week ago. I think there is another way to design the lift that will be lighter weight, and have appropriate factors of safety, but haven't had the priority to work on it. From: "Reid Siebert" Subject: Re: COZY: Nose gear lift device Date: Wed, 25 Nov 1998 06:22:57 -0600 Steve Wright's Noze Lift is the kit I have. I'm installing it in my Cozy right now. Email address: SWrightFLY@aol.com From: "Pengelly, Stan L" Subject: RE: COZY: Re: MKIV NG15 Nose gear casting cracked Date: Wed, 25 Nov 1998 13:30:49 -0600 The problem is grain size. A casting in this application is at risk. Perhaps we as builders/pilots of these airplanes should inspect for cracks in the casting as part of the annual inspections . Maybe even x-raying. Another solution would be to replace the casting with a machined or forged part. I know: very expensive. But a casting used the way it is in the Cozy will be prone to a failure. Stan L. Pengelly Cozy IV plans #539 > ---------- > From: Wilhelmson, Jack[SMTP:Wilhelmson@scra.org] > Sent: Wednesday, November 25, 1998 11:17 AM > To: 'C van Hoof'; cozy_builders@canard.com > Subject: RE: COZY: Re: MKIV NG15 Nose gear casting cracked > > From looking at the Photos of the broken NG15 casting it appears that > there > maybe several areas > to investigate to analyze this and other cases of this casting breaking. > Once we have a example of a failure mode, the reason for the failure can > be > at least be theorized. > > 1. From the design it is evident that the stresses that are locked up by > the > fastening bolts will be > added to the stresses applied from the wheel hitting obstructions. Two > possible solutions to this > come to mind. First, don't over tighten the fastening bolts. Use only > the torque nessary to hold the casting. Second the casting could be > redesigned so that the fastening bolts went from the side direction rather > than fore and aft. > > 2. The casting fracture is typical of crystalline fractures caused by > fatigue. Fatigue fractures can often be traced to locked up stress from > the > original casting process. When the metal cools it cools unevenly leaving > stress locked up in the part. When these locked up stress are added to the > in service load stresses the part fails. All cast parts should be heat > treated to normalize the locked up stress. Most casting aluminum requires > a > four to eight hour heat treat at 1000 degrees F and a > quench in boiling water to normalize it for critical applications. Some > manufacturers skip this because it is risky (Aluminum melts at 1050 to > 1100 > F). Also, it costs money. > > Jack Wilhelmson N711CZ > > > > -----Original Message----- > > From: C van Hoof [SMTP:cvh@iafrica.com] > > Sent: Saturday, November 21, 1998 1:30 PM > > To: cozy_builders@canard.com > > Subject: COZY: Re: MKIV NG15 Nose gear casting cracked > > > > Hi Carl & others > > > > > > We witnessed a similar breakage, but not at slow speed. > > > > At our 1997 Sun'n Fun Groblersdal meeting, Dave O'Neil's longEze did a > > normal landing, but when the nosewheel touched down it broke the > > casting, the amazing thing was that the a/c kept the landing > > configuration (but now without the wheel). Of course, Dave had to get > > out and pull it off the tar runway ... all this on video, but > > unfortunately of _very_ poor quality ... The casting was of the older > > units - his Eze is over 10 yrs old. > > > > if you want more info, i can ask... > > > > chris > > Cozy Mk IV #219 still building... > > > Date: Wed, 25 Nov 1998 12:39:28 -0600 From: Tom Brusehaver Subject: Re: COZY: Re: MKIV NG15 Nose gear casting cracked >1. From the design it is evident that the stresses that are locked up by the >fastening bolts will be added to the stresses applied from the wheel >hitting obstructions. Two possible solutions to this come to >mind. First, don't over tighten the fastening bolts. Use only the >torque nessary to hold the casting. Maybe I mis-read the instructions, but I thought the casting was to be floxed on, as well as bolted. Would the floxing affect the torquing? Like does it really need to be so tight, considering the whole socket would be making really good contact? I realize there is the possibility that the flox could crack, then the bolts are there for backup. From: "DL Davis" Subject: RE: COZY: Re: MKIV NG15 Nose gear casting cracked Date: Wed, 25 Nov 1998 19:28:08 -0500 I had an NG15 failure also. It broke in the same way as has been described by others here. Unfortunately for me, it failed at the one of the most inconvenient remote airports that I have ever landed at, Tangier Island in the middle of the Chesapeake Bay. I knew the runway was not the greatest, so I had been very careful on the speed, touched down gently, let the speed bleed off, and let the nose down carefully. Since this airport seems to be about 6 inches above sea level, the runway had some hills and valleys from the frequent flooding. So on my rollout, the airplane had a little hop here and there. On the second or third hop the nosewheel simply snapped off and I skidded to a stop on the peg leg. When I tell other flyers that story I know they're thinking "yeah sure, I bet he crashed on the runway!" But it really was a pretty decent landing. I still don't understand why the casting decided to break then. Believe me, I've made worse landings. It took me about 30 minutes to fly there, and 10 hours to get back home via boat and car. I borrowed a fellow builder's nose strut and returned a week later for repairs. No problems since then, but I still don't really understand the failure. (I also haven't returned to Tangier Island). Dewey Davis Date: Thu, 26 Nov 1998 10:51:56 -0500 From: Bill Theeringer Subject: COZY: Nose crank dimensions ......The crank handle does not fit inside the connecting tube. It is about .040 too big. This will mean that I turn down the handle shaft or drill open the tube. If I drill open the tube that I fear the wall thickness will be too thin. ----------- Jannie; It sounds to me like the aluminum tubing you are using has too thick a wall. The tubing should be 3/8 OD with a 0.035 wall thickness. The crank handle shaft typically has a dimension of 0.302 to 0.307. I make the nose gear ratchet and I have to bore out a hardened steel gear to accept the shaft. I bore it to 0.305 as this seems to be the most common shaft size. Those with 0.308 shafts have to sand them down a few thousanths and those with a dimension around 0.302 have to oval the shaft a little and force it in. The shaft on my Brock crank is 0.303 and is a sloppy fit to the aluminum tubing of about 2 or 3 mils. HTH ll Theeringer N29EZ See our award winning Long EZ with Jim Newmans excellent retractable gear at http://www.flash.net/~infaero/infgear.htm Composite Aircraft Accessories HOME: 805-964-5454, SHOP: 805-964-5453 E Mail: Composite_Aircraft_Accessories@Compuserve.com PO Box 21645 Santa Barbara, CA 93121 "Once you have tasted flight, you will walk with your eyes turned skywards, for there you have been, and there you will long to be" Leonardo DaVinci (1452-1519) From: GunMechInc@aol.com Date: Thu, 26 Nov 1998 20:16:46 EST Subject: Re: COZY: Nose crank dimensions You talk about turning the tube on the crank down or boring out the tube. Try cutting the tube off and use a piece of aluminum rod and machine it to fit both pieces. Jack F. walker Vari-Eze N52EZ From: cdenk@ix.netcom.com Date: Wed, 25 Nov 1998 19:58:13 -0600 (CST) Subject: Re: COZY: Re: MKIV NG15 Nose gear casting cracked Tom Brusehaver wrote The NG15 is bolted tight causing bending (prying) stresses in the casting before the flox sets. The top bolts are in tension, adding to the original bending in the casting due to wheel spinup, bumps, and friction. This force is in the aft direction, basically at the axle level (ignoring bearing friction), with a fulcrum or pivot near the bottom of the fiberglass strut. With an aft force at the axle, a pivot point in the middle, and the top bolts at the top with a counteracting forward force. It is possible that just the bolts could cause the crack, but it seems to be more a fatigue issue. The flox helps hold things together, acting more as a shim to prevent rattling movement, and providing some friction along the sides. The bond in tension on the aft face is not reliable, and should be ignored, with shimming the only function. The only real place the friction is counted on is to prevent the casting from sliding off the end of the strut. And this is one of the main functions of the 4 bolts. Someone else recently suggested inspection at annual, NO NO, every flight!, just like you look at elevator hinges. Date: Thu, 26 Nov 1998 10:03:00 -0800 Subject: COZY: Re: MKIV NG15 Nose gear casting cracked From: alwick@juno.com (ok How) On Wed, 25 Nov 1998 13:30:49 -0600 "Pengelly, Stan L" writes: >The problem is grain size. A casting in this application is at risk. >Perhaps we as builders/pilots of these airplanes should inspect for cracks >in the casting as part of the annual inspections . Maybe even x-raying. If you have a grain size problem with any casting, xraying will not show a thing. Although a casting failure could have a connection to the grain size, it would never show on xray. Alum grains can only be measured by polishing the sample, looking at it under magnification. Then visually compare to some photo's in an astm standards book. Pretty crude, but fairly accurate. All modern foundries now use a more proactive and accurate method of pouring a sample into a test cup and measuring the temperature of the material as it solidifies. This provides a repeatable accurate number measuring grain size and "modification" factors. >Another solution would be to replace the casting with a machined or forged >part. I know: very expensive. But a casting used the way it is in the Cozy will be prone to a failure. Personally feel our nose gear is ideal application for an aluminum casting. Haven't done any sort of stress analysis, but considering the long flexible arm of front gear it should be a piece of cake. I'm not impressed with three features of the nose gear design. 1) they machined the highest stress locations with a sharp radius. This greatly reduces fatique and ultimate strength. I haven't seen the failed pics (where are they?), but I would expect a failure to occur at corner of bottom two bolt tabs. 2) The bolt attachment looks to be very prone to overtorque, thus the casting can easily be stressed behond the ultimate strength of the material. This MAY induce micro cracks which then spread due to cycling... fatigue. 3) Attachment to gear places all the load on the attach pads. If casting was placed on opposite side of gear, it would largely be in compression and less likely to fail. Additionally, alum castings are vulnerable to the occasional freak piece that has an internal "shrinkage" defect. Shrinkage defects are by far the #1 cause for casting failures. You can have 500 castings with a substantial safety margin, but one with shrinkage defects can be produced and fail in the field. This is why aircraft industry requires 100% xray of castings... that darned freak piece. By magnifying the broken section you should be able to determine if shrinkage is involved. I'm skeptical about the grain size and "they forgot to heat treat" explanations previously posted. But have to admit that either of those could be possible causes. Just not likely in my opinion. Easy to determine by maginifying broken section. I had someone request a tutoral on alum casting. I never finished it, but it's pretty interesting subject that few have been exposed to. So I include it below fwiw. What is aluminum? Seems like a stupid question, but it’s good to realize that "aluminum" is actually an alloy. Aluminum itself has poor mechanical properties. So they add "filler" to make the mix bind better. Exact same concept as our use of flox to bind epoxy. The percentage of filler varies depending on the alloy, but generally they add a bunch of Silicon to fill the gaps, Magnesium, Copper, Manganese, Chromium, and normally a little Titanium. Effect of alloy elements Great, so they add other elements to make the aluminum stronger. Unfortunately, there is a negative effect of adding other elements to aluminum. Not all of the elements transition from liquid to solid at the same temperature. Usually the liquid alum is held at around 1300 f. When the manufacturer converts the liquid to a solid, when he casts the aluminum, the alloy does not all become solid at the same moment. As a result, some of the alloy elements tend to clump together. This is particularly true for sand castings because sand is not very good at conducting heat. So you end up with a casting that has a distribution of elements that varies location to location. This is the reason aluminum is heat treated. It’s necessary to bring the material almost back to the liquid state. At that state, these clumps of alloy material will naturally disperse through the casting. They actually move away from each other. "Solution" means that the alum was heated to appx 1000 deg F(typically for 8 hours) and then dumped in water. At this 1000 F the alum is almost liquid again (thus the term "solution") and the individual components of the alloy like silicon, titanium, tend to disperse evenly in the alum sheet. Dumping in water just locks the homogeneous elements in place, else they would clump together again. After solution, alum is highly malleable. But after a day or so it looses malleability. It ages naturally. Mfgs use artificial aging only because natural aging takes years. They don't want alum product to change it's properties with time. Usually aging is done 1 day after solution. The product is placed in an oven at around 325F for a few hours. To give you a feel for how antiquated the aluminum industry is, I did a lot of testing to find the effects of reducing the solution cure time from the normal 8 hours to as little as ½ hour. Interesting that there is no significant difference in mechanical properties after the second hour of solution. Yet all of the manufacturers still put each part through an 8 hour solution. Conversely however, the aluminum industry has made some very substantial improvements to improve the consistency of mechanical properties. Major improvements in the last 10 years. -al wick 87% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components. Expect completion date 6-21-99. ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] From: cdenk@ix.netcom.com Date: Fri, 27 Nov 1998 07:00:29 -0600 (CST) Subject: COZY: MKNG15 FAilure Nat wrote Yes, I do frequently takeoff at 1900 lbs, with the wife and I in the front seat. We total 320 lbs, while I use a front seat limit of 400 lbs. With the wife and I and a gross of 1900 lbs, the static nose wheel load is 235 lbs. For the 3 place CoZY I calculate for a gross of 1600 lbs. and forward C.G. of 97.5, the nose load is 215 lbs., an 9% overlaod. BUT, my entire nose gear area is MKIV details. Now for the MKIV with a gross of 2050 lbs., C.G. of 97.5", main wheels at F.S.= 110", and nose wheels at F.S.=17 (I had 2 different responses to my request for info at this point, this is close, and won't change the numbers enough to matter), I calculate nose load at 275 lbs. On a few occasions, I have operated with 1900 lbs gross, and 400 lbs. in the front seat, then the nose wheel load is 273 lbs., still less to near equal to the MKIV limits. From: "Nat Puffer" Subject: COZY: MKIV-15A Date: Thu, 26 Nov 1998 13:24:30 -0600 Dear Builders, We think we have about 35 Cozy Mark IVs flying, and NONE OF THESE have reported any problems with the nose gear. We have close to 500 hours on ours and I am a former Navy Carrier Pilot (you know, we are used to dropping our planes on the deck from 20 ft.) There is only one reported failure of the MKIV-15A, and it wasn't on a Mark IV. It occurred on Uli's COSY design which admittedly was being flown over gross with a very heavy nose. I believe Dewey Davis had the Long EZ gear (completely different) on a 3-place Cozy. LETS NOT GET CARRIED AWAY! Happy Thanksgiving. Nat Date: Thu, 26 Nov 1998 21:12:20 -0500 From: David Domeier Subject: Re: COZY: MK IV DIMENSIONS WANTED Carl, re " Could someone look at the back cover of the instructions and get met the location of the nose and main gear axles (Fuselage stations [F.S.]). Also the allowable forward C.G. location at the maximum takeoff weight of 2050 lbs." My MKIV Flight Handbook is at the hangar but here are some numbers stored in my computer. These are measurements of my airplane and those of the proto type. Nose gear = 17.9 (plan = 17.6) Main gear = 110.25 (plan = 109.5) CG range = 97.5 forward limit, 102.0 aft limit. I think the cg limit is the same no matter what the airplane weighs, but I need to read the FHB to confirm it. Hope this helps. dd From: Fritzx2@aol.com Date: Thu, 26 Nov 1998 22:44:18 EST Subject: Re: COZY: MK IV DIMENSIONS WANTED Carl, >Could someone look at the back cover of the instructions and get met the location >of the nose and main gear axles (Fuselage stations [F.S.]). >From the back of the MK IV plans, the main gear axle is at FS 110 and the front axle is at FS 16. >Also the allowable forward C.G. location at the maximum >takeoff weight of 2050 lbs. >From the MK IV owner's manual, the forward C. G. location at max weight (also the same for all weights) is at 97.5. I smell a new front gear design a brew'n. John Fritz fritzx2@aol.com Date: Thu, 26 Nov 1998 12:52:30 +0200 From: Jannie Versfeld Subject: COZY: Brock Parts - Nose Gear Dear builders, I am busy with my nose gear box and discovered some mis fitting parts and would like some advice on what_to_do and if anyone else have the same problem. All parts were purchased from Brock. The crank handle does not fit inside the connecting tube. It is about .040 too big. This will mean that I turn down the handle shaft or drill open the tube. If I drill open the tube that I fear the wall thickness will be too thin. Although the tube fits perfectly inside the universal (also supplied by Brock) the sleeve (which I presume must be the exact size as the tube in diameter and wall thickness) fits perfectly inside the universal but the same problem as fitting over the worm gear shaft. To make this sleeve fit I will also have to either turn down the worm gear shaft or drill open the sleeve. It is my contention that the tube and sleeve is of the wrong dimension or alternatively the worm gear shaft and crank handle shaft would be the problem. It is known that Brock is an approved supllier and I will be taking the matter up with them. I must also state that Brock's service was excellent fast and the alway kept me up_to_date with progress on my back orders and shipping. Now what benifits do we as Cozy Builders have dealing with "Approved Suppliers"? I believe if there were to be a second/third supplier the quality of the goods will surely improve. Referring to the nose wheel fork situation. Comments Please, Jannie Versfeld #673 Date: Sat, 22 Nov 1997 12:38:41 +0100 From: Jean-Jacques CLAUS Subject: Re: COZY: Design and Material Quality Control - Landing Gear andCastings Nat Puffer wrote: > > I have a copy of Uli Wolter's owners manual, which is basically a copy of > Cozy Dev. Cozy III manual, and it lists 1500 lbs. as maximum gross weight, > except under certain special conditions take-off can be at 1600 lbs. gross > (if he has changed this, he hasn't informed me). In the COSY EUROPE newsletter #62 & #63 ( july/oct 98 ) ULI WOLTER wrote : "INCREASED MAX TAKE OFF WEIGHT The MAXTOW of 800kg ( 1764 lbs ) in the utility category for the COZY and the COSY CLASSIC is only valid if you made the changes introduced in NL#37 ( WING TORSION )and NL#38/39 ( CANARD ). If you have not incorporated these modifications your MAXTOW is 725kg ( 1600 lbs. ), normal category as outlined in the COZY owners manual." You must know ( i'm sure you already knows )that an a German independant aeronautical expert did a calculations folder of the COSY CLASSIC ( do you have one for the MKIV ? ). So ULI modified ( reinforcement ) canard attach points and add a wing torsion reinforcement to permit to use the COSY CLASSIC in the utility category ( normal +3.8Gs, utility +4.4Gs ). According to FAR23 the structure has to be designed to sustain a minimum factor load of 1.5 ( 150% ) for safety reasons. As we say in French ( A famous language for proverbs ( with the chineese, of course)) : "Une chaîne a la résistance de son maillon le plus faible" Translated : "A chain has the resistance of its weakest link" In the Carl's case, may be the MKNG15 was only the "weakest link". Jean-Jacques CLAUS PS : On sept 21st, ULI WOLTER performed the first flight of the NEW COSY CLASSIC KIT. This "COSY KIT" is supplied by SC AERO ( French Sailplanes manufacturer ). For more information contact mailto:flyclassic@aol.com From: "guy Terren" Subject: Re: COZY: Design and Material Quality Control - Landing Gear and Castings Date: Thu, 26 Nov 1998 14:56:45 +0100
Jean Jacques,

The problem is: there will be no "luggage compartment" in my Cozy
..............., perhaps not an approved design ????


I completely agree with you. I also bought the MKNG15 castings and it is the
original design from the authorized supplier.

I also bought the canard fittings from the authorized supplier. They fit so
badly, i had a 2 days work assembling the hinge inserts.

I don't speak of numbers of fax sent by brocks and to brocks because they
back-ordered to France and claimed for shipping as i never ask them anything
in that way.

I think the REAL problem is not to try to eliminate suppliers by
"mandatory", but to find new suppliers to have them competiting.


Guy

-----Message d'origine-----
De : Jean-Jacques CLAUS <jjclaus@club-internet.fr>
À : Cozy Builders <cozy_builders@canard.com>
Date : jeudi 26 novembre 1998 11:28
Objet : Re: COZY: Design and Material Quality Control - Landing Gear and
Castings


>Hi all,
>
>Anyone knows who is the designer of the MKNG15 casting ?
>
>Nat, Brocks, both or other ?
>
>Recently i purchased one from Brocks.
>It cost me $350 + $70 ( french tax 20% ) + port, say $450 total for a
>part that would crack at anytime , anywhere in the future, well !.
>
>In my case, it seems that the MKNG15 casting is the original design from
>the authorized supplier.
>
>So what do i do ?
>Do i mount my MKNG15 casting knowing that it would fail and put a second
>one in the luggage compartment ?
>
>Nat, any comments and/or MANDATORY ?
>
>
>Jean-Jacques CLAUS
>
>
 From ???@??? Thu Nov 26 14:31:55 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id XAA28265 for ; Wed, 25 Nov 1998 23:14:12 -0500 (EST) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id XAA11434 for cozy_builders-list; Wed, 25 Nov 1998 23:08:03 -0500 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from ligarius-fe0.ultra.net (ligarius-fe0.ultra.net [146.115.8.189]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id XAA11427 for ; Wed, 25 Nov 1998 23:07:59 -0500 Received: from zeitlinhome ([146.115.235.235]) by ligarius-fe0.ultra.net (8.8.8/ult.n20340) with SMTP id XAA29420 for ; Wed, 25 Nov 1998 23:05:16 -0500 (EST) Message-Id: <199811260405.XAA29420@ligarius-fe0.ultra.net> X-Sender: marcz@pop.ultranet.com X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0 Date: Wed, 25 Nov 1998 23:01:48 -0500 To: Cozy Builders Mailing List From: "Marc J. Zeitlin" Subject: COZY: Design and Material Quality Control - Landing Gear and Castings Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "Marc J. Zeitlin" X-UIDL: 0d116479cc14f3cb2de57ac82e26cb30 Jack Wilhelmson wrote wrt casting cracking: >> 1. From the design it is evident that the stresses that are locked up by >> the fastening bolts will be added to the stresses applied from >> the wheel hitting obstructions..... >> .... Second the casting could be >> redesigned so that the fastening bolts went from the side direction rather >> than fore and aft. >> 2. The casting fracture is typical of crystalline fractures caused by >> fatigue ......... All cast parts should be heat >> treated to normalize the locked up stress. Stan Pengelly wrote wrt casting cracking: >Another solution would be to replace the casting with a machined or forged >part. I know: very expensive. >But a casting used the way it is in the Cozy will be prone to a failure. As a Mechanical Engineer, after looking at the photos on bil kleb's web pages, I concur completely with both Jack's and Stan's statements and interpretations of the casting cracking. It seems as though there are two major deficiencies in this part - one known one in the basic design, and one potential one in the manufacturing process. The design defect causes the landing stresses (variable and repetitive) to be added to the bolt stresses (variable with temperature cycles and installation). After an unknown number of cycles, these added stresses can (not will, but can and have in at least two reported cases here) lead to cracks and breakage. As far as the potential MFG defect, it may be the case that the manufacturer of these parts (Brock) heat treats them correctly, or it may not. We don't know the specifications for the part, nor whether they are carried out correctly. However, due to the design defect, even if the parts are made perfectly (no voids, correct heat treat), there is still a potential problem due to the design defect, as Stan states so succinctly above. I'd like to claim a parallel between the issue of MKNG15 casting cracking and possible landing gear strut spreading. In one case, we've got at least two verified cases of an approved part breaking and causing a potential safety issue through no fault at all of the builder(s) (at least according to the builders). In the other case of the landing gear struts, we've got a history of some small number of parts made by the approved supplier (for V.E.'s, L.E.'s, and COZY III's) using a substantially similar design to that of the MKIV gear strut, having a spreading problem if not used in the recommended manner - i.e. lifting a wing and letting the gear return to the inboard position after parking. We also have at least one case (and possible four or more) of a landing gear strut made by an unapproved supplier (and maybe the approved supplier) exhibiting the same behavior, although we don't know whether or not the builder(s)/flyer(s) followed all the recommended procedures. We have the unapproved supplier's word that the parts are made to specifications, and this supplier is willing to back up his word with evidence for anyone who asks for it. We know that this spreading (if it continues too far) can be a safety issue, although Vance Atkinson has stated that some spreading and reduction in camber/castor angle is "a good thing". Here's the analogy, for those of you still paying attention: We've had some people claim that the vendor of the unapproved gear struts should be financially liable for any problems with the struts, as well as claim that these struts are/could be unsafe and that people shouldn't buy them. We've had no such claims regarding the approved castings, although the evidence for the design/mfg deficiencies in these parts is incontrovertible. I have both parts on my aircraft - the approved casting, and the unapproved landing gear strut. Personally and professionally (as an engineer), I am much more concerned about the long term viability of the casting than I am about the gear strut (assuming I perform the stress reduction maneuver described previously). If, however, either one of these parts were to fail, I would not expect anyone to reimburse me for the cost of the parts or the damage to my aircraft, any more so than I would expect Mazda to reimburse me for the $2300 I just spent on my MX-3 to get a clutch, water pump, top end job, valves, timing belt, etc., or the $800 I spent on the front 4-wheel drive hub on my Isuzu Trooper. Now, car manufacturers have recalls in which they fix things for free if there's a defect, but this situation doesn't exist in the certificated aircraft world, much less in the experimental aviation world. The only thing I expect in any case is that IF a design or manufacturing deficiency were to come to light (as it has with the casting and may in the future with the gear strut or other parts) that the designer would redesign the parts to eliminate the known defect and the manufacturer would modify their processes to produce the part correctly. I would then expect the designer/manufacturer to offer the "fixed" parts to previous purchasers at cost, as a gesture of goodwill for the problems caused. The ONLY time I would expect remuneration from the designer/manufacturer is if there were proof that they KNEW that the design/manufacturing was defective at the time of purchase. There is absolutely no evidence of this being the case in either of the two failure modes discussed here. I'm not trying to start a flame war here - I'm merely stating some observations of two different failure situations and my opinions of the respective responsibilities of designers and manufacturers of parts used in experimental aircraft. -- Marc J. Zeitlin marcz@ultranet.com http://www.ultranet.com/~marcz/ From: "Nat Puffer" Subject: Re: COZY: Design and Material Quality Control - Landing Gear andCastings Date: Thu, 26 Nov 1998 11:30:20 -0600 Dear Builders, We are still waiting for a picture of Carl Denk's broken casting and his recommendations for improvement. If we are going to improve something, we first need more information on the problem. To set the record straight, Carl is flying a Cosy 3-place, but with a MKNG-15 nose gear casting assembly, I believe. He said his airplane is nose heavy, and he has been flying at 1900 lbs gross at a maximum forward c.g. I have a copy of Uli Wolter's owners manual, which is basically a copy of Cozy Dev. Cozy III manual, and it lists 1500 lbs. as maximum gross weight, except under certain special conditions take-off can be at 1600 lbs. gross (if he has changed this, he hasn't informed me). I don't know what weight is on Carl's nose gear, but at 1900 lbs. gross and maximum forward c.g., it could well be in excess of what was expected of the MKIV-15A design. Nevertheless, if it can be improved to increase the safety factor, we are all for it. We don't know of any other MKIV-15A assembly which broke, so we don't know if this will turn out to be an isolated case. The other reported failure was by Dewy Davis, but he is flying a Cozy 3-place, I believe with Burt Rutan's original NG-15A casting. I believe there have been a number of Long EZs which have had nose gear failures. The forks used to break, but I think Burt redesigned to a heavier fork. I don't know what the record is on NG-15As in Long EZs. Burt won't let anyone else change one of his parts, so the best we can do is to improve the MKNG-15A. I understand that both Mike and Dick on their round the world flights were taking off well in excess of 2,000 lbs. gross, but it probably wasn't at maximum forward c.g., and they were probably much lighter in landing. When installing MKIV-15A on the strut, the MKIV-15A casting could be stressed unnecessarily if you tighten the bolts too tight before the flox is cured. The flox is supposed to fill up any irregularities so the pressure applied by the bolts is evenly distributed over the entire casting. Will mention this in Builder Hints while awaiting more information from Carl. Regards, Nat From ???@??? Sun Nov 29 15:49:20 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id AAA23453 for ; Sat, 28 Nov 1998 00:58:33 -0500 (EST) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id AAA16285 for cozy_builders-list; Sat, 28 Nov 1998 00:54:48 -0500 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from strato-fe0.ultra.net (strato-fe0.ultra.net [146.115.8.190]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id AAA16280 for ; Sat, 28 Nov 1998 00:54:44 -0500 Received: from zeitlinhome ([146.115.235.235]) by strato-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with SMTP id AAA19203 for ; Sat, 28 Nov 1998 00:51:44 -0500 (EST) Message-Id: <199811280551.AAA19203@strato-fe0.ultra.net> X-Sender: marcz@pop.ultranet.com X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0 Date: Sat, 28 Nov 1998 00:34:02 -0500 To: Cozy Builders Mailing List From: "Marc J. Zeitlin" Subject: COZY: Design and Material Quality Control - Landing Gear andCastings Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "Marc J. Zeitlin" X-UIDL: 45e0254a36fecc4010e58f93df2f2bbb Nat Puffer writes (via email); >Dewey Davis confirms that he had the Long EZ/Cozy III NG15-A, and that the >Mark IV MKNG15A "looks a bit beefier". So who are the two confirmed >failures of the MKNG15A? If there aren't two (2), how about acknowlegeing >this? As I said to Nat in a private email, I misinterpreted Dewey's original post regarding his nose gear failure - I thought I read that he was using the MKNG-15A for the MKIV. I used this to claim that there were two failures of MKNG-15A castings. Clearly this is now shown to be incorrect, and I apologize for my mistake and doubling the number of failures incorrectly. However, given the low number of MKNG-15A castings in use (with any appreciable time or takeoff/landing cycles on them), one structural failure is one failure too many. Carl D. has confirmed that the load on his nosegear is less than (or at least no more than) would be experienced in a COZY MKIV, so it seems as though he was not overloading the piece outside of it's design envelope. At any rate, while I will certainly fly my aircraft with the casting as installed, I will certainly inspect it before each flight as part of the pre-flight, as Carl recommends. I also sincerely hope to see a redesigned part in the near future for sale by Brock or another authorized supplier. -- Marc J. Zeitlin marcz@ultranet.com http://www.ultranet.com/~marcz/ Date: Sun, 29 Nov 1998 18:02:15 +0200 From: Rego and Noleen Burger Subject: COZY: Design and Material Quality Control - Landing Geatand Castings Like all sensations things will get modified,expanded and blown out of preportion. I just had a Brand new tyre delaminate on my car returning from Cape Town having visited Ernie DeGovia and his nice three placer that's taking good shape. No one want's a tyre to go faulty but they do as Nat says "it is impossible for an engineer to design something which will never fail." Also we must bear in mind that a designer works 90% with theory. It is the manufacturer who must perform the task of achieving this design goal. Now we're talking a different ball game. So don't be quick to blame the designer, better still don't look for blame at all, find ideas to improve or correct the problem, I feel blaming is becoming part of the problem. If you want answers to the cause of the failure the manufacturer should be involved in the discussion. -- Rego Burger CZ4#139 South Africa Web:http://home.intekom.com/glen/rnb.htm Work e-mail, mailto:burgerr@telkom.co.za From: "Nat Puffer" Subject: Re: COZY: Design and Material Quality Control - Landing GearandCastings Date: Sat, 28 Nov 1998 16:05:51 -0600 Cozy Builders, I object to Marc's posting, first of all that there were two confirmed failures, which he has apologized for, but then his statement that there are a low number of MKNG-15A castings in use. We think that there are at least 35 Mark IVs flying, a number for over two years, and our proof of plans model has been flying for over 6 years with almost 500 logged hours and several hundred landings. There are also a number of Uli's Cosys flying with our MKNG-15A gear, and who knows how many other designs are using this, and ONE reported failure. I have not yet received the casting which failed. There could be a number of reasons apart from the design or fabrication of the part. I have objected to Marc's comparison of the nose gear castings to several confirmed cases of landing gear struts from an unauthorized supplier which have spread. These are two separate matters. Lets not cry "fire" in a crowded theater. Give the designer some time to study the problem, if there is one. I might mention that I have heard of a number of nose gear failures on the Velocity and even factory built airplanes. This isn't an excuse, but it is impossible for an engineer to design something which will never fail. Regards, Nat From: "neal newman" Subject: Re: COZY: Design and Material Quality Control - Landing Gear andCastings Date: Sat, 28 Nov 1998 06:57:36 -0500 Hi Marc,Nat and all From what I have been reading On this matter... It seems to me there are 2 different MKNG15A's one for the longEZ/Cozy3 and one for the COZYMKIV.. if this is the fact why do they both have the same designation? and how do you tell them apart? or did I read it wrong as usual and not see the MKNG15A,MKNG15-A If thats the case.. thats Dumb...it would still be easy for the manufacturer to send the wrong part..and For a Builder to Overlook this slight change in designation.. It should be named something Else...maybe add IV after the A like MKNG15AIV.. I have Not ordered Mine....YET... just food for thought..... Neal Newman Cozy 3place #226 CozyMKIV #659 chapter9 From ???@??? Mon Nov 30 22:07:41 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id GAA01657 for ; Mon, 30 Nov 1998 06:09:30 -0500 (EST) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id GAA24327 for cozy_builders-list; Mon, 30 Nov 1998 06:11:20 -0500 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from smtp1.mailsrvcs.net (smtp1.gte.net [207.115.153.30]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id GAA24321 for ; Mon, 30 Nov 1998 06:11:16 -0500 Received: from jraero (1Cust247.tnt4.mia1.da.uu.net [153.35.37.247]) by smtp1.mailsrvcs.net with SMTP id FAA04379 for ; Mon, 30 Nov 1998 05:07:57 -0600 (CST) Message-ID: <36627D9B.3BE3@gte.net> Date: Mon, 30 Nov 1998 06:12:27 -0500 From: "Jeff S. Russell (http://www.AeroCad.com)" Organization: AeroCad Inc. X-Mailer: Mozilla 2.02E-KIT (Win95; U) MIME-Version: 1.0 To: Cozybuilders Subject: Re: COZY: Re: MKIV NG15 Nose gear casting cracked References: <19981125205311419169@ix.netcom.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "Jeff S. Russell (http://www.AeroCad.com)" X-UIDL: a64653d90164ef4b7e55d8120c217ca7 cdenk@ix.netcom.com wrote: > > Tom Brusehaver wrote > > The NG15 is bolted tight causing bending (prying) stresses in the casting before the flox > sets. I install the flox using only snug pressure on the bolts. After cure (about 1 week) I then tighten them. -- Jeff From: "Pengelly, Stan L" Subject: RE: COZY: MKIV-15A Date: Mon, 30 Nov 1998 07:53:46 -0600 I agree that we should not get carried away. Every change to a design requires much thought. I do not pretend to be an expert in aluminum castings and certainly the safety record of the Cozy/Long Ez aircraft is admirable. However, in the nearly twelve years of doing mechanical design on things like rocket engines and space stations I have found there is always an improvement that can be made to a design. Maybe just a material change here or a process change there. But there is always an improvement to be made. As far as aircraft experience is concerned, I worked as a flight line mechanic on F-111F, U-2, KC-135, T-38 and SR-71 jet aircraft. My specialty was flight controls and landing gear. During my many nights and days working jets, I don't think I ever saw a casting used on a major landing gear component. And when I went to college to get a BS in mechanical engineering and castings were discussed, the subject of grain size and fatigue was always an issue. I like the design as is. But experience has shown me that every design has a flaw and every design can be improved. Stan L. Pengelly Cozy Mk IV plans #539. > ---------- > From: Nat Puffer[SMTP:cozy@extremezone.com] > Sent: Thursday, November 26, 1998 1:24 PM > To: cozy_builders@canard.com > Subject: COZY: MKIV-15A > > Dear Builders, > We think we have about 35 Cozy Mark IVs flying, and NONE OF THESE have > reported any problems with the nose gear. We have close to 500 hours on > ours and I am a former Navy Carrier Pilot (you know, we are used to > dropping our planes on the deck from 20 ft.) There is only one reported > failure of the MKIV-15A, and it wasn't on a Mark IV. It occurred on Uli's > COSY design which admittedly was being flown over gross with a very heavy > nose. I believe Dewey Davis had the Long EZ gear (completely different) on > a 3-place Cozy. LETS NOT GET CARRIED AWAY! Happy Thanksgiving. > Nat > From: cdenk@ix.netcom.com Date: Mon, 30 Nov 1998 09:00:49 -0600 (CST) Subject: RE: COZY: MKIV-15A Pengelly writes The flight school at our airport has a collection of failures that are shown as part of the class work, don't trust anything. One piece is a casting (or maybe forging), the top main gear strut from a Piper Aerostar. It has a nice crack in it. Nothing is immune! Date: Mon, 30 Nov 1998 17:13:38 -0800 From: "LCDR James D. Newman" Subject: COZY: Re: MKNG15 Failure Hi Carl, Wayne and All, > Carl Denk wrote: > Nat wrote > Yes, I do frequently takeoff at 1900 lbs, with the wife and I in the front seat. We total 320 lbs, > while I use a front seat limit of 400 lbs. With the wife and I and a gross of 1900 lbs, the static > nose wheel load is 235 lbs. For the 3 place CoZY I calculate for a gross of 1600 lbs. and forward > C.G. of 97.5, the nose load is 215 lbs., an 9% overlaod. BUT, my entire nose gear area is MKIV > details. Now for the MKIV with a gross of 2050 lbs., C.G. of 97.5", main wheels at F.S.= 110", and > nose wheels at F.S.=17 (I had 2 different responses to my request for info at this point, this is > close, and won't change the numbers enough to matter), I calculate nose load at 275 lbs. > > On a few occasions, I have operated with 1900 lbs gross, and 400 lbs. in the front seat, then the > nose wheel load is 273 lbs., still less to near equal to the MKIV limits. Normal nose wheel loads should be between 10 to 20% of the aircraft weight (reference any landing gear design book). A 2050 lb. aircraft nose strut worst case scenario of 20% is 410 lbs. The best compromise (for spam cans) is to have approximately 15% of the weight of the airplane on the nose wheel at the static level attitude, which is 307.5 lbs. There are 3 home built designs (spam configuration) that have 25 to 35+% of the aircraft weight on the nose wheel, leading to several nose strut collapses upon landing when they were first introduced. Now, because we fly canards, have such a small elevator, and don't have prop wash blasting over a large elevator, the lighter the load on the nose strut, the less the take off roll. But no less than 205 lbs. (10% of 2050 lb. aircraft weight) should be on the nose strut. If nose wheel weight is less than 10%, for example 8%, a slow oscillation in pitch, called "porpoising", may occur. This oscillation in pitch has not been encountered with more forward positions of the C.G.., so probably will not happen as long as you are within the aft C.G. limit. Also, too light of nose wheel load will make nose wheel steering (if you have it) inadequate. > Wayne Hicks wrote: One must also consider that using the nose lift puts more strain on the casting, too, especially while lifting the nose with two people already seated. Is this more than the force applied in bad landings? I don't know... But one could pre-suppose more up and down cycles than botched landings. If memory serves while I write tonight, a 2200 lb. aircraft loaded at the forward C.G. will exert ~460 lbs. on the nose wheel and tire to raise the plane off the ground from the kneel position, which requires about 2550 lbs. of force in the approximate area of the spring attachment to the nose strut. > A partial of my post to the group Sept. 23, '98: "Another note (food for thought): from FAR Part 23.479, using a Limit Load Factor of 3.00, a Landing Weight (LW) of 1325 lbs. could impose over 953 lbs. of load on the *nose* strut and tire from a hard 3 point landing with the aircraft loaded at the _fwd._ CG (worst case scenario); 800 lbs. LW, 576 lbs. nose strut and tire load; 900 lbs. LW, 720 lbs. load; 1500 lbs. LW, 1079 lbs. load; 1700 lbs. LW, 1223 lbs. load; 2050 lbs. LW, 1475 lbs., and at 2200 lbs. LW, 1583 lbs. load. So max Landing Weight for this tire is about 1625 lbs." Looking forward to what the investigation of the MKIV-15A actually reveals. Sounds like the bolts through the tabs are over torqued without the benefit of cured flox to crush against. Maybe a torque valve for the nuts against the cured flox needs to be determined and published so the tabs are not stressed. HTH. Infinity's Forever, JD From: "Pengelly, Stan L" Subject: RE: COZY: Re: MKIV NG15 Nose gear casting cracked Date: Mon, 30 Nov 1998 14:07:21 -0600 The reason I suggested x-raying was for detecting cracks, not for grain inspection. I found several outfits on the Web which do x-raying of aluminum castings. Grain inspection can be done with x-ray interferometry, which is pretty sophisticated and beyond the resources of most Cozy builders. Dye penetrant inspection can be used also to spot surface cracking. Unfortunately, the materials and equipment necessary, like x-raying, are not found in a Wicks catalog. I have done microscopy of metals to observe grain patterns and measured average grain size. Here again it is expensive and is a destructive test if the sample is taken from the part under consideration. Along with the concern grain size is also orientation. Grain boundaries in castings run perpendicular to the part surface, which provides a path for crack growth. Grains in forgings won't form this way and also tend to be smaller. My original suggestion to inspect annually or maybe x-ray still stands. It's obviously up to the prudent builder/pilot to determine what to do, if anything. Mentioning a change to a forging or a machined part was more a suggestion to Nat. If anyone can tweak a design and improve it with little or no risk and keep the cost down, he can. Stan L. Pengelly Cozy IV plans #539 From ???@??? Mon Nov 30 22:07:56 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id NAA29730 for ; Mon, 30 Nov 1998 13:20:10 -0500 (EST) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id NAA30833 for cozy_builders-list; Mon, 30 Nov 1998 13:18:49 -0500 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from indy.spacetec-inc.com (host2.spacetec-inc.com [209.96.176.2]) by twc2.betaweb.com (8.8.5/8.8.5) with SMTP id NAA30825 for ; Mon, 30 Nov 1998 13:18:42 -0500 Received: from hicky.spacetec-inc.com by indy.spacetec-inc.com via SMTP (940816.SGI.8.6.9/940406.SGI.AUTO) for id KAA06935; Mon, 30 Nov 1998 10:10:47 -0800 Received: by localhost with Microsoft MAPI; Mon, 30 Nov 1998 13:07:54 -0500 Message-ID: <01BE1C62.71055460@hicks@spacetec-inc.com> From: "L. Wayne Hicks" To: Cozy Builders Mailing List Subject: COZY: RE: Landing Gear andCastings Date: Mon, 30 Nov 1998 13:07:52 -0500 Organization: SpaceTec Ventures, Inc X-Mailer: Microsoft Internet E-mail/MAPI - 8.0.0.4025 Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "L. Wayne Hicks" X-UIDL: 5cc802e96a39111774bab82382d372e8 -----Original Message----- From: Marc J. Zeitlin [SMTP:marcz@ultranet.com] Sent: Saturday, November 28, 1998 12:34 AM To: Cozy Builders Mailing List Subject: COZY: Design and Material Quality Control - Landing Gear andCastings Nat Puffer writes (via email); >Dewey Davis confirms that he had the Long EZ/Cozy III NG15-A, and that the >Mark IV MKNG15A "looks a bit beefier". So who are the two confirmed >failures of the MKNG15A? If there aren't two (2), how about acknowlegeing >this? Zeitlin replies: Carl D. has confirmed that the load on his nosegear is less than (or at least no more than) would be experienced in a COZY MKIV, so it seems as though he was not overloading the piece outside of it's design envelope. My Reply: One must also consider that using the nose lift puts more strain on the casting, too, especially while lifting the nose with two people already seated. Is this more than the force applied in bad landings? I don't know... But one could pre-suppose more up and down cycles than botched landings. Wayne Hicks Cozy IV #678 Chapter 9 From: cdenk@ix.netcom.com Date: Mon, 30 Nov 1998 15:23:29 -0600 (CST) Subject: Re: COZY: RE: Landing Gear andCastings Hicks writes Would be nice if this loading was considered in the redesign of the nose wheel area. This would be a neat improvement to the Cozy. Date: Tue, 01 Dec 1998 07:09:30 -0500 From: bil kleb Subject: Re: COZY: Re: MKIV NG15 Nose gear casting cracked ok How wrote: > > I haven't seen the failed pics (where are they?) carl has them for the asking. i also put them online at: http://www.geocities.com/~kleb/homebuilt/other.html -- bil Date: Tue, 01 Dec 1998 07:35:55 -0500 From: bil kleb Subject: Re: COZY: Design and Material Quality Control - Landing Gear andCastings neal newman wrote: > > It seems to me there are 2 different MKNG15A's one for the longEZ/Cozy3 > and one for the COZYMKIV.. sort of, but not quite they are not marked the same. for the longEZ/Cozy3/etc it is NG-15 and for the cozy iv it is MKNG-15. ^^ ^^^^ > -----Original Message----- please DO NOT include entire previous message; please check your mailer's default settings! -- bil Date: Wed, 02 Dec 1998 14:33:15 -0500 From: David Domeier Subject: COZY: Cozy MKIV Nose Gear Weight To all, I’ve been experimenting with a spread sheet and have determined that when the Cozy MKIV is loaded to 2050 lbs. and the CG is at 97.5 (forward limit), the weight on the main gear is 1758 lbs. and the weight on the nose gear is 292 lbs. When the Cozy MKIV is loaded to 2050 lbs. and the CG is at 102.5 (aft limit), the weight on the main gear is 1872 lbs. and the weight on the nose gear is 178 lbs. Forward Limit Computations Weight Arm Moment Main 1758 110.25 193819.5 Nosewheel 292 20.9 6102.8 Total 2050 97.523 199922.3 Aft Limit Computations Weight Arm Moment Main 1872 110.25 206388 Nosewheel 178 20.9 3720.2 Total 2050 102.491 210108.2 The nose gear is at 20.9 inches because the airplane must be level to compute CG limits. Since my airplane sits about 1.5° nose up with the NG fully extended, I retracted it partially to level the fuselage. The nose gear center line moved aft from 17.9 to 20.9 inches. One does not normally taxi out and take off with the nose gear slightly retracted, so the weight on at NG is slightly less when it is fully extended. But I think CG computations must be made using 20.9 (my airplane) because the CG limits are referenced to a level fuselage base line. What happens in flight might be interesting to discuss. One does not fly around at 0° AOA. The CG must move aft as the airplane is rotated for take off. Obviously, all this is factored into setting CG limits. What would really be interesting is having a method of determining Center of Lift on each airplane. Then we could set CG limits not based on the proto type, but on your machine. (These airplanes are not all alike,reasonably close, but not identical) The key of course is to keep the CG forward of the CL throughout the entire speed envelope. I suspect that the Center of Lift is far aft of 102 at min speed because the CG obvouisly is somewhere aft of that point also due to the nose high attitude of the airplane at full aft stick just before the canard stalls. dd From ???@??? Thu Dec 03 23:36:21 1998 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id JAA03916 for ; Thu, 3 Dec 1998 09:11:27 -0500 (EST) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id JAA30168 for cozy_builders-list; Thu, 3 Dec 1998 09:11:23 -0500 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from scra_nt1.SCRA.ORG (scra_nt1.scra.org [147.120.100.226]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id JAA30155 for ; Thu, 3 Dec 1998 09:11:13 -0500 Received: by scra_nt1.scra.org with Internet Mail Service (5.5.2232.9) id ; Thu, 3 Dec 1998 09:07:27 -0500 Message-ID: <28C1D35F1A45D2119A4C0008C7FA56D22B1E27@scra_nt1.scra.org> From: "Wilhelmson, Jack" To: "'David Domeier'" , cdenk@ix.netcom.com Cc: cozy_builders@canard.com Subject: COZY: RE: COZY: Cozy MKIV Nose Gear Weight Date: Thu, 3 Dec 1998 09:07:26 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2232.9) Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by twc2.betaweb.com id JAA30157 Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "Wilhelmson, Jack" X-UIDL: a9297980fe1c5a96475092e017d2490e David: If you go farther with this you will find that when the airplane is nose down the CG moves approx. 13 in forward and the nose gear support point moves back approx 11 in. This occurs because the CG is 48 in above the main wheel rotation point. The result is that a full gross forward CG MKIV will have 460+ lbs. on the nose wheel when it starts to raise the airplane. This force is not higher than what happens on a hard landing if you are looking only at the wheel and it's supports. However, the pivot points at the upper end of the gear are put under completely different loads in the partly retracted position. Jack Wilhelmson N711CZ From: "Nat Puffer" Subject: COZY: MKNG-15 installation Date: Mon, 7 Dec 1998 12:45:43 -0600 Dear Builders, This will be in newsletter #64, but it won't hurt to explain it more than once. The MKNG-15 nosegear casting is bonded to the strut with flox and also clamped to the strut with four 1/4 in bolts. Jack Wilhelmson did a stress analysis of the casting for us. He neglected the flox bond and the bolt tension and assumed the worst possible case bending load of the casting on the strut, i.e., a gross weight of 2050 lbs and a c.g. at the forward limit of 97.5, and a 2 g. landing (that's a pretty hard landing) he calculated a safety factor for the casting of 2.1 (a safety factor of 1.5 is required). The flox bond increases the safety factor, but bolt tension reduces it. The bolts can put a bending and shear stress on the casting ears. To maximize the safety factor, therefore, he suggests that you increase the bond strength by adding additional flox between the casting and the backup plate and that you should also minimize the bolt tension. Use only enough bolt tension to hold the assembly in place while the flox cures. He suggests only snugging the bolts, and not exceeding a torque value of 10 in-lbs. This is just the opposite of what most people would expect. One of our builders wrote to us that he saw one Mark IV and a couple of Long EZs where the bolts had been tightened so tight that the ears of the castings were bent. These are probably failures waiting to happen. Best regards, Nat From: Epplin John A Subject: RE: COZY: MKNG-15 installation Date: Mon, 7 Dec 1998 15:12:02 -0600 Nat writes: > To maximize the safety factor, therefore, he suggests that you > increase the bond strength by adding additional flox between the casting > and the backup plate and that you should also minimize the bolt tension. > Use only enough bolt tension to hold the assembly in place while the flox > cures. He suggests only snugging the bolts, and not exceeding a torque > value of 10 in-lbs. This is just the opposite of what most people would > expect. > [Epplin John A] Talk about lucking out! This is exactly what I did about a year ago. Made a note to tighten the bolts during final inspection. My reasoning was not the same, figured that it was prudent to not squeeze every last drop of epoxy out of the joint or warp the back plate. John Epplin Mk4 #467 From: cdenk@ix.netcom.com Date: Mon, 14 Dec 1998 12:29:05 -0600 (CST) Subject: COZY: Landing gear info wanted: I have been chasing several details on 3/4 place Cozys, and could use the following info for at least several planes: Nose gear: 1: Color of your spring strut spring (yellow or red) 2: From observing the wear on the spring strut (should be visible from underneath without removing anything), the length of movement (compression) for the highest repetition movement and the maximum movement. Could be in the inch range, measured to nearest 1/16" 3: The NG6 AN5 pivot bolt condition, after removing the nut, and no weight on nose wheel, can the bolt be moved lengthwise with finger pressure. Its not necessary to remove just move a 1/4" is sufficient. I'm looking for bolts that are bent slightly causing jambing. 4: if providing above info, the empty weight and C.G. Main Gear (3 place only) 1: The distance between the bottom inboard ends of the fiberglass main gear after rolling forward at least 15 feet, and backward 15'. 2: If providing above info, the empty weight, C.G., and fuel on board. Thanks...