Date: Sat, 14 Mar 1998 21:02:51 -0500 From: Ian Douglas Subject: COZY: Rudders Hi All, I am just finishing the skinning of my winglets and want to know it there is any reason I can cut the rudders out prior to bonding to the wing. It seams to me that it would be much easier to work on the rudders while the winglet is not attached to the wing. -- Best regards, Ian D.S. Douglas MK0069 Date: Sat, 14 Mar 1998 12:38:47 -0500 From: "Jeff S. Russell http://www.AeroCad.com" Subject: Re: COZY: Rudders Ian Douglas wrote: > > I am just finishing the skinning of my winglets and want to know it > there is any reason I can cut the rudders out prior to bonding to the > wing. It seams to me that it would be much easier to work on the > rudders while the winglet is not attached to the wing. Ian, I did this on the Velocity I built and the AeroCanard. The lower winglets were not on the airplanes but I added small ones on the latter with no problems. -- Jeff Russell/AeroCad Inc. P.O. Box 7307 Port St. Lucie FL. 34985 Shop# 561-460-8020 Home# 561-343-7366 Composite workshop info: http://www.Sportair.com From: "Nat Puffer" Subject: Re: COZY: Rudders Date: Sat, 14 Mar 1998 19:18:33 -0600 Dear Ian, The rudders extend down into the lower winglets, which are not added until after the upper winglets are installed. The lower winglets are required to give the airplane lateral stability at aft stick and aft c.g. They also extend the safe c.g. range by 1/2 inch, so I don't know how you could cut out the rudders until after both upper and lower winglets are installed. It is not difficult to cut out the rudders after the winglets are installed. Best regards, Nat ---------- > From: Ian Douglas > To: Cozy MK IV Builders > Subject: COZY: Rudders > Date: Saturday, March 14, 1998 8:02 PM > > Hi All, > > I am just finishing the skinning of my winglets and want to know it > there is any reason I can cut the rudders out prior to bonding to the > wing. It seams to me that it would be much easier to work on the > rudders while the winglet is not attached to the wing. > -- > Best regards, > Ian D.S. Douglas > MK0069 From: cdenk@ix.netcom.com Date: Sat, 14 Mar 1998 22:23:09 -0600 (CST) Subject: Re: COZY: Rudders On 03/14/98 21:02:51 you wrote: > >Hi All, > >I am just finishing the skinning of my winglets and want to know it >there is any reason I can cut the rudders out prior to bonding to the >wing. It seams to me that it would be much easier to work on the >rudders while the winglet is not attached to the wing. >-- >Best regards, >Ian D.S. Douglas >MK0069 > > I cut after attaching to the wing, and doing the filling. That way the pieces will matchup better. Date: Sun, 15 Mar 1998 08:04:05 -0800 From: Michael Antares Subject: COZY: Cozy re: Rudders Having installed both of my winglets and having cut out the rudders, I agree with NOT cutting them out until the winglets are installed IF you are going to put on the lower winglets (and I did). You won't be able to effectively line up the uppper and lower portions of the winglets beforehand since part of the rudder is formed after the lower winglet is installed--there's a lot of filling and matching at that point. Michael 11597 Summerhome Park Road Forestville, CA 95436 707.887.7260 Cozy#413 Finished through chap 14 except chap 13. Chaps 16 & 24 mostly finished. Chapters 20 and 21 finished. Date: Sun, 15 Mar 1998 17:12:06 -0500 From: Ian Douglas Subject: Re: COZY: Rudders Thanks for all the replies. I still intended to put on the lower winglets (they are also skinned) but thought that it might be easier to cutout and install all of the hardware and rudders while I could have the winglet held at any angle require for easy access. Since the overwhelming majority say not to do it, I'll follow the plans and do it after joining to the wing. Guess I'm on to the turtle back as I have to wait for my inspection of shear webs to be completed prior to finishing the wings. -- Best regards, Ian D.S. Douglas Director of Technology Workplace Technologies Corporation If you write software, send me your resume! Date: Mon, 16 Mar 1998 08:15:24 +0200 From: Rego Burger Subject: COZY: Rudders I found no problem as per plan. I just needed a good few friends to help mount the winglet, after that I did all the rudder work on my own, only used a loose hacksaw blade to cut it out.....no fancy tools. Rego Burger, web site: http://home.intekom.com/glen/rnb.htm (home e-mail) mailto:rnb@intekom.co.za RSA From: "DeFord, Brian" Subject: COZY: Opinions: Internal rudder belhorns (CH20) Date: Mon, 15 Jun 1998 09:06:00 -0700 I'd like to get a quick survey of builders already flying with the internal rudder belhorns installed versus the POR (plan of record) external belhorn installation. I like the idea of it all being hidden, but has it been a problem in any way? Any differences worth noting for those who have flown both ways? Just curious and would like to hear some opinions... Brian DeFord From: cdenk@ix.netcom.com Date: Mon, 15 Jun 1998 15:57:05 -0500 (CDT) Subject: Re: COZY: Opinions: Internal rudder belhorns (CH20) I have over 600 hours on them and wouldn't have it any other way. There have been 2 issues: The bellcranks at the firewall where the cables come aft and then go up had to be revised to change the amount of movement of the rudders coordinated with the brakes, this was required on the COSY, but I can't speek for the rest. At Rough River once before I had control locks, the wind was banging the rudders resulting in a broken cable. Easily repaired when got home, and wasn't a issue for the flight. From: "Marc J. Zeitlin" Subject: COZY: winglet positioning Date: Fri, 26 Jun 98 10:56:47 EDT Wayne Walter Peterson writes (but majordomo bounced it): >I am just about to place the winglet on the wing on my Berkut, and can >one of you please give me a hand? > >I want to make sure both leading edges are at the same angle. > >The wing are on the plane and set up correctly and we use the RAF >Long-Ez type set up with the WPRP.The only thing I see different is that >we hang a plumb bob from the top of the winglet on the outboard side and >the string should be 4.0 inch from the bottom trailing edge of the >winglet.Negative dihedral.I see no note of useing 118.35 inch from WPRP >to the aft tip of winglet.The RAF Long-Ez plane said that the trailing >edge of the winglet is 78.64 dergees off the top of the winglet when you >cut your foam for the winglet.When I placed the template on the bottom >of the winglet I tried to cut perpendicular and as well as I could >do.But when I place the winglet on the wing the winglet is not level on >the top of the winglet.It appears that I must trim off some more of the >fore aspect of the winglet to make the top level. > >Did I not trim off the right amount? > >I would think the Cozy is the same way in this aspect of the plans. >Does it say if the top of the winglet is level? Does the Cozy plans or >anyone know what the angle is of the leading edge of the winglet? > >I would think the Nat would have this answer in his plans as it would be >something that would come up in building the Cozy. >I am stuck and can't go on til I know if the top of the winglet is level >or know the angle of the leading gdge of the winglets. >Any help will be appreciated.Hope to meet some of you at the Cozy dinner >at EAA on that Sat. night. Thanks, :-) Wayne Peterson. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Wed, 01 Jul 1998 08:13:38 -0500 From: Wayne Walter Peterson Subject: COZY: BERKUT: Just an update. I am putting the winglets on the wings.My fuselage sits Bondoed to saw horses that are bolted to the floor.The main spar is in place,but the strakes are not in place.I don't have C kit as of yet.The wings are in place with the bolts.I made a jig that is Bondoed to the spar in two places,Bondoed also to the floor.The wings are supported by large concrete blocks which are Bondoed together and Bondoed to the floor.The wings without the strakes in place do not flop around and the distance from the centerline of the instrument panel to that point that is 4.5 inches aft of the leading edge of the wing is 202inches and 5/8th on each side.I sanded the fore aspect of the lower winglet to make that level I superglued to the top of my winglet level.I get 62 degrees for the leading edge of the winglet.The leading edge of the winglet is 102.15 inch from the WPRP, and the trailing edge is 108.35 inch from the WPRP. I am just about to put the Bondo to the Winglet/wing area.Is 62 degrees sound right? Wayne Date: Wed, 01 Jul 1998 07:43:34 -0400 From: David Domeier Subject: Re: COZY: comparing canard to main wing incidence Phil, Good post on incidence. re "I had also heard some horror stories from builders who had had their wings twist during storage between build and final assembly." My rudders were stored on a shelf subject to temps over 100 degrees for about 3 years and I'm sure the left one warped somewhat. It does not fit the winglet as if it were cut from it and the middle hinge line is off just a bit. The rudder functions OK but I am not satisfied with the fit - but haven't figured out what to do about it. dd From: cdenk@ix.netcom.com Date: Tue, 30 Jun 1998 19:15:01 -0500 (CDT) Subject: Re: COZY: winglet-wing problem Peterson writes The Cosy Classic has 3 dimensions from the inboard forward corner of the aileron cutout. The Leading and trailing edges where the winglet intersects with the wing top surface, and the top (I forget whether its the leading or trailing edge). I wouldn't trust these dims for a different plans. You should check with Ronnenburg for questions like this. The Bercut may have a different location which results in better performance. Date: Wed, 01 Jul 1998 01:48:19 -0500 From: Wayne Walter Peterson Subject: COZY: winglet-wing problem Wayne Walter Peterson wrote: > > I am just about to place the winglet on the wing on my Berkut, and can > one of you please give me a hand? > > I want to make sure both leading edges are at the same angle. > > The wing are on the plane and set up correctly and we use the RAF > Long-Ez type set up with the WPRP.The only thing I see different is that > we hang a plumb bob from the top of the winglet on the outboard side and > the string should be 4.0 inch from the bottom trailing edge of the > winglet.Negative dihedral.I see no note of useing 118.35 inch from WPRP > to the aft tip of winglet.The RAF Long-Ez plane said that the trailing > edge of the winglet is 78.64 dergees off the top of the winglet when you > cut your foam for the winglet.When I placed the template on the bottom > of the winglet I tried to cut perpendicular and as well as I could > do.But when I place the winglet on the wing the winglet is not level on > the top of the winglet.It appears that I must trim off some more of the > fore aspect of the winglet to make the top level. > > Did I not trim off the right amount? > > I would think the Cozy is the same way in this aspect of the plans. > Does it say if the top of the winglet is level? Does the Cozy plans or > anyone know what the angle is of the leading edge of the winglet? > > I would think the Nat would have this answer in his plans as it would be > something that would come up in building the Cozy. > I am stuck and can't go on til I know if the top of the winglet is level > or know the angle of the leading gdge of the winglets. > Any help will be appreciated.Hope to meet some of you at the Cozy dinner > at EAA on that fri. night. Thanks, :-) Wayne Peterson. Date: Tue, 14 Jul 1998 04:25:42 -0500 From: Wayne Walter Peterson Subject: COZY: BERKUT: I am just about to attach the winglets to the wings and it seems that there is a number of variations with how much the top of the winglet should lean,if at all. The RAF Long-Ez plans page 20-2 say to use the three measurements.From what I understand they were given in the Canard Pusher newsletter 26 on page 6. A; WPRP to leading edge of the winglet 102.15 inch B; WPRP to trailing edge of the winglet 108.35 inch C; WPRP to the top of the trailing edge of the winglet 118.35 inch RAF notes that "C is not critical and can be plus or minus 1 inch" It is the last measurement that seems to have variation between the Long-Ez,Berkut,and the Velocity.I have not been able to find out from a builder what the Cozy does in this area. Long-Ez: It looks as if the winglet is leaning, with the top of the winglet more inboard on a Long-Ez I saw last week.I did not put an angle finder on the outboard aspect of the winglet.The plane would have to be level in roll.I put the angle finder on the leading edge of the winglet with a level on the longeron and can up with 62 degrees.From looking at the Long-Ez plans retro fit to make the larger rudders the leading edge is 60 degrees if one assumes the top of the winglet is level with the waterline. Velocity: The outboard aspect of the winglet is vertical. The leading edge of the winglet is 60 degrees. Berkut: The top of the winglet leans outboard. I measured 62 degrees with an angle finder on the leading edge. Which is the best? Does the Long-Ez really lean inboard? Could a Cozy builder add their imput? I placed a string on the WL (BL) that is on the sand down template of top winglet.Both wings and winglets are mounted on the plane(Bondoed).The string was then run to the walls of my shop(fore and aft of plane).My shop is 29 feet 1 inch long. I placed a string at the centerline at the same height.The distance from the centerline to the winglet line(mounted on the wall,fore aspect)is 16 inches less than the distance from centerline to the winglet line(mounted on the wall,aft aspect).The TE of the top of the winglet is ~47.5 inch from the aft wall. I would assume this is what Burt Rutan had designed into the Long-Ez. Has anyone else looked at the amount of angle for the winglets? Does it sound as my winglet have the right amount of angle? What is the benefits of changing the amount of lean on the winglets inboard or outboard? Has anyone done wing tunnel testing as which give the least amount of drag? My wings/winglets are Bondoed in place,I would like to get to that first lay-up.But now, I can't commit til I have a better understanding of the risks and benefits of changing Burt's design. Wayne Peterson Date: Wed, 15 Jul 1998 00:07:15 -0400 From: "Marc J. Zeitlin" Subject: Re: COZY: BERKUT: Wayne Walter Peterson writes (wrt Berkut); >The RAF Long-Ez plans page 20-2 say to use the three measurements.From >what I understand they were given in the Canard Pusher newsletter 26 on >page 6. >A; WPRP to leading edge of the winglet 102.15 inch >B; WPRP to trailing edge of the winglet 108.35 inch >C; WPRP to the top of the trailing edge of the winglet 118.35 inch > >RAF notes that "C is not critical and can be plus or minus 1 inch" >Which is the best? It's best to do what the plans say. I >Does the Long-Ez really lean inboard? Yep. >Could a Cozy builder add their imput? The COZY MKIV numbers are identical to the L.E., with the same tolerance on the 118.35" dimension (the tol. on the other two dims is 0.05"). >What is the benefits of changing the amount of lean on the winglets >inboard or outboard? I would venture a guess that there's no particular benefit or loss to changing the angle within the tolerance range - the angular difference is small. >Has anyone done wing tunnel testing as which give the least amount of >drag? Surely you jest :-). >My wings/winglets are Bondoed in place,I would like to get to that first >lay-up.But now, I can't commit til I have a better understanding of the >risks and benefits of changing Burt's design. I know you've mentioned this issue before, and I'm sorry that no one on this list has been able to help you out to your satisfaction. You've mentioned that you haven't been able to get in touch with anyone at the Berkut factory, but that's where I'd keep plugging. Check with Richard Riley at: Berkut@loop.com or check with any one of the other Berkut builders that have gotten past this point. I think the berkut web pages have some links to builders for contact information. Good luck. -- Marc J. Zeitlin                     marcz@burnside.ma.ultranet.com 3 Sweetbriar Way                  http://www.ultranet.com/~marcz Acton, MA  01720                 http://cozy.canard.com/ Date: Tue, 14 Jul 1998 22:58:46 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: BERKUT Hi Wayne, Marc and All, >> The RAF Long-EZ plans page 20-2 say to use the three measurements. From what I understand they were given in the Canard Pusher newsletter 26 on page 6. Which is the best? > It's best to do what the plans say. In this case, true. >> What is the benefits of changing the amount of lean on the winglets inboard or outboard? > I would venture a guess that there's no particular benefit or loss to changing the angle within the tolerance range - the angular difference is small. True, concerning Marc's statement above of staying within the tolerances. But there are advantages and disadvantages to having more or less of an angle, and there are ways to correct the small disadvantages :-). >> Has anyone done wing tunnel testing as which give the least amount of drag? > Surely you jest :-). Yes, NASA. We've done computer wind tunnel tests too. >> My wings/winglets are Bondoed in place, I would like to get to that first lay-up. But now, I can't commit til I have a better understanding of the risks and benefits of changing Burt's design. > I know you've mentioned this issue before, and I'm sorry that no one on this list has been able to help you out to your satisfaction. You've mentioned that you haven't been able to get in touch with anyone at the Berkut factory, but that's where I'd keep plugging. Check with Richard Riley . . . If you can't get a hold of Richard or Dave, call and I'll discuss with you what little bit I know concerning winglet angle issues for all aircraft. OBTW - some of what you are asking has been discussed before and is (should be) in the archives. Infinity's Forever, JD From: mikefly@juno.com Date: Wed, 15 Jul 1998 14:31:20 +0000 Subject: Re: COZY: Berkut >Does the Long-Ez really lean inboard? Yes it does. When a Long EZ rudder is deflected, it causes three reactions. Yaw in the direction of the deflected rudder, drag also causing yaw in the direction of the deflected rudder and since the rudder is also deflected slightly upwards it will cause a small roll reaction. ( left rudder = left yaw and roll ) More inboard winglet lean = more roll reaction. Good if you want a high roll rate. Bad when cross controlling for cross wind correction on landing. mbb _____________________________________________________________________ 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: Fred I. Mahan Date: Thursday, July 16, 1998 7:00 PM Subject: COZY: Re: radio interference >I meant to say "Micro Encoder" not "Micro Monitor." Sorry for the >confusion. I think I'm on Ron's s**t list now! From: EJCV@aol.com Date: Fri, 17 Jul 1998 13:31:56 EDT Subject: COZY: Rudder induced Roll It seems to me that any roll caused by rudder application will be against the rudder application, not with it as has been suggested. The outward deflected rudder will reduce the pressure "inside" i.e. twards the fuselage, the winglet and this reduced pressure will act on the upper surface of the wing inducing a rolling moment against the rudder input significantly greater than any input due to the winglet not being vertical. A related piece of useless information is that rudder deflections on a delta aircraft where the fin and rudder are over the wing have the same undesirable effect. This is why the fin on Concorde is behind the wing. Eddie Vann Date: Sat, 18 Jul 1998 10:01:19 -0400 From: David Domeier Subject: Re: COZY: Rudder induced Roll Eddie, re "The outward deflected rudder will reduce the pressure "inside" i.e. twards the fuselage, the winglet and this reduced pressure will act on the upper surface of the wing inducing a rolling moment against the rudder input significantly greater than any input due to the winglet not being vertical." If I read and interpret that sentence correctly, it says left rudder will cause a right roll. I think you're ignoring the drag caused by the deflected rudder. It definitely cause the MKIV to roll left. dd From: mikefly@juno.com Date: Sat, 18 Jul 1998 19:37:32 +0000 Subject: Re: COZY: Rudder induced Roll On Fri, 17 Jul 1998 13:31:56 EDT EJCV@aol.com writes: >It seems to me that any roll caused by rudder application will be >against the >rudder application, not with it as has been suggested. > >The outward deflected rudder will reduce the pressure "inside" i.e. >twards the >fuselage, the winglet and this reduced pressure will act on the upper >surface >of the wing inducing a rolling moment against the rudder input >significantly >greater than any input due to the winglet not being vertical. > >A related piece of useless information is that rudder deflections on a >delta >aircraft where the fin and rudder are over the wing have the same >undesirable >effect. This is why the fin on Concorde is behind the wing. > >Eddie Vann > I understand what you are saying. Perhaps Burt designed them to cant inward to counter the reduced pressure on top of the wing. Also, the winglet is mounted more aft than the wing it is mounted to and is swept causing the reduced pressure to actually be behind the wing as you suggest on the Concord. If that is the case, then the lift vector from an inward canted inglet would be slightly downward and any asymetry between left and right winlets (ie. deflectd rudder) would cause a roll. Mike Bowden Two EZ MS1 _____________________________________________________________________ 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] Date: Fri, 31 Jul 1998 11:19:45 -0700 Subject: COZY: lower winglet help From: alwick@juno.com (ok How) I could sure use some advice. In the distant past, when I hot wired my lower winglets, they came out great except the bottom portion has less material than expected. Doesn't look like the plans. I know that all my core dimensions were correct. I strongly suspect I used the wrong template for the bottom of the core. I could find nothing in the archives about this. Very embarrasing to be the only one to screw this up. So here is the question. What template is supposed to be used to cut the bottom winglet core? I used the "winglet tip" template and the "winglet root-use for top and bottom winglet". Are we supposed to use two of the "winglet root..." templates? Thanks -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. _____________________________________________________________________ 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] Date: Thu, 06 Aug 1998 23:59:12 -0400 From: "Marc J. Zeitlin" Subject: Fwd: COZY: lower winglet help Al Wick wrote; >....... I strongly suspect I used the wrong >template for the bottom of the core. I could find nothing in the archives >about this. Very embarrasing to be the only one to screw this up. >So here is the question. What template is supposed to be used to cut the >bottom winglet core? I used the "winglet tip" template and the "winglet >root-use for top and bottom winglet". Are we supposed to use two of the >"winglet root..." templates? There's a template specifically for the bottom of the lower winglet - it's on the plan sheets somewhere and is labeled. If you used the winglet top template, you'll need to make them over again. No biggie, if you've got a few scraps of foam - they're not real large. Just remember that you've got to get the camber correct - it's sort of reversed from the large template to the small one. Check the archives for chapter 20 a couple years back - I think this was discussed a bit. -- Marc J. Zeitlin                     marcz@burnside.ma.ultranet.com 3 Sweetbriar Way                  http://www.ultranet.com/~marcz Acton, MA  01720                 http://cozy.canard.com/ Date: Thu, 10 Sep 1998 16:08:21 -0700 Subject: COZY: hidden rudder bellhorn From: alwick@juno.com (ok How) I just finished installing the hidden rudder bellhorn. Definitely recommend it if you are interested. It was not difficult at all. Can easily be done as a retrofit. I didn't have to make any changes to the cable path. I did come up with a neat trick that eliminates the hardest part. I used hot glue to secure a thin board to the outside of the rudder. This board was used to line up the internal bellhorn when floxing the horn in place. The board controlled the position and length of the bellhorn. It also controlled the horn clearance to the rudder skin. Seems like the first bellhorn took about 6 - 8 hours. Second one took 3 hours. I use a 1/2" diam wood drill bit to drill out the plastic conduit as my first step. The pilot diam on the wood bit just keeps following the conduit no matter where the conduit goes. Only problem is, having built everything, I am now out of excuses to delay sanding. -al wick 84% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components, now installing rudders. Expect completion date 4-30-99. _____________________________________________________________________ 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 Or call Juno at (800) 654-JUNO [654-5866] From: cdenk@ix.netcom.com Date: Thu, 10 Sep 1998 20:57:48 -0500 (CDT) Subject: Re: COZY: hidden rudder bellhorn It may be necessary when installing the flush bellhorns, depending on you brake/rudder pedal geometry to adjust the amount of cable movement. This is done by altering the length of the arms on the bellcranks aft of the firewall at the aft end of the fuselage cable. Originally I had a set of pulleys there to change the direction. but changed it to the belcranks. Date: Fri, 11 Sep 1998 17:32:09 -0700 Subject: COZY: Hidden rudder bellhorn 2 From: alwick@juno.com (ok How) I rec'd a bunch of private email regarding the bellhorn I installed. The plans don't have anyone's name or address on them. Someone put a lot of effort to develop them. Are these being sold or what? I don't want to distribute any copies if it's not freeware. The only identifier is the N number in the photo's. N26MS. Can someone clue me in? -al wick 84% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components. Expect completion date 4-30-99. _____________________________________________________________________ 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 Or call Juno at (800) 654-JUNO [654-5866] From: Jim Hocut Subject: RE: COZY: Hidden rudder bellhorn 2 Date: Fri, 11 Sep 1998 22:47:18 -0400 On Friday, September 11, 1998 8:32 PM, ok How [SMTP:alwick@juno.com] wrote: > .... Someone put a lot of > effort to develop them..... The > only > identifier is the N number in the photo's. N26MS.....> N26MS is Mike Mellville's Long EZ. Sounds like you've got a copy of plans from RAF, who as I understand it still have those plans available for $10. Their e-mail address is raf@hughes.net. (How much did Burt pay you for the advertisement?) Jim Hocut jhocut@mindspring.com Date: Mon, 14 Sep 1998 13:55:05 -0700 Subject: COZY: Mass balance of rudder From: alwick@juno.com (ok How) I'm puzzled as to why the plans don't call for rudder mass balance. I understand how critical it is for aileron and elevators, but can't see why it's not important for rudders. Any ideas out there? Thanks. -al wick 85% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components. Expect completion date 4-30-99. _____________________________________________________________________ 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 Or call Juno at (800) 654-JUNO [654-5866] Date: Mon, 14 Sep 1998 22:08:43 -0400 From: bil kleb Subject: Re: COZY: Mass balance of rudder ok How wrote: > > I'm puzzled as to why the plans don't call for rudder mass balance. I > understand how critical it is for aileron and elevators, but can't see > why it's not important for rudders. Any ideas out there? the first reason that flutter is not an issue when using the airbrake style of rudders is that they only deflect in one direction. a typical control surface flutter scenario requires that the control surface is free to move to either side of center so that the energy can grow unabated from one cycle to the next, feeding on the aerodynamic energy pouring by the flight surfaces. the second reason that rudder flutter is generally not an issue is due to the fact that the aspect ratio (span/chord) is very low. a low aspect ratio usually implies a relatively stiff structure whose fundamental frequencies are very different from the aerodynamic forcing frequencies. (flutter occurs when you "hit the natural frequency", i.e., both the structural and aerodynamic forcing match each other.) a simplified(?) (two-dimensional) airfoil-aileron flutter scenario proceeds as follows: the airfoil hits a disturbance and plunges upward. the unbalanced aileron trails in a downward position, creating lift and a nose-down pitching moment. due to the extra lift the airfoil continues it's plunge motion upward, but due to the nose-down pitching moment, it also begins to rotate. eventually the airfoil pitches to the point that the lift becomes negative and the momentum of the unbalanced aileron diminishes to the point that the whole mess starts plunging downward and the process begins anew, only this time in the downward direction. and, if you're really not having a good day, the amplitudes of the motion will grow exponentially until structural failure. (typically all this occurs in less than the span of a second, so there is no time for user input; and the smallest amount of play in the control linkages is typically enough to allow onset.) -- bil Date: Tue, 15 Sep 1998 08:02:54 +0200 From: Rego Burger Subject: COZY: Mass balance of rudder I guess its not required for one major reason, the airflow around our winglets is not symetrical like on a standard rudder where you have an even "push pull" battle with the airflow over it ( this could promote flutter). Instead on the wingleted type of installation we have a slightly higher pressure on one side to the other tending to keep it in place. Added to this the rudders are spring-loaded, this acts as an anti-flutter damper too. If you look at the design of the rudder it can't move in-board by the stopper, it can only move outboard into the slip-stream... so I guess there is no need for counter balances. 2c worth. Rego Burger Web site: http://home.intekom.com/glen/rnb.htm e-mail home- mailto:rnb@intekom.co.za RSA From: cdenk@ix.netcom.com Date: Fri, 20 Nov 1998 20:11:56 -0600 (CST) Subject: Re: COZY: Winglet Access On 11/20/98 20:50:44 you wrote: > >>>Just a question to add to the lower winglet saga.......... My >grandfather is REbuilding a Long EZE from a hull and box of parts. One >of the lower winglets has an access panel on the inboard side. The >cutout has a coax cable and a single wire running into it. Has anyone >else mounted an antenna out there? Or could this "cubby hole" have >been used for something else? > >Thanks in advance, >Chris Holt<< >_____________________ > >Chris; > >I built just such a door into my left bottom winglet during construction >around 1985. I ran two pieces of coax into it. One feeds a 5/8 wave base >loaded vhf (144 - 148 Mhz) vertical and the other feeds the base of the HF >(3 to 30 Mhz) vertical. The VHF radiating element is a piece of 1/8 brass >welding rod that protrudes from inside the box out through the bottom of >the winglet rudder cutout (large rudders) and continues up against the >forward face of the cutout, secured with nylon clamps. It is not uncommon >to have communication with stations 300 miles away with this antenna. > >The other coax feeds the base of a 5/8 inch diameter aluminum tube that is >glassed into the leading edge of the winglet. The top of this rod >protrudes an inch above the top of the winglet and is threaded, accepting >resonators for various HF bands. Worldwide communication is routine with >this antenna. Both coax shields and the wing imbedded ground radials are >connected together inside the box forming a non resonant counterpoise. The >right winglet is the per plans com antenna. In my opinion the 5/8 vertical >works far better than the com antenna. I had one of these on my 150 years >ago and it also worked very well. The base loaded coil is manufactured by >New Tronics. > >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) > > I have one at the base of an Antenna Dynamics Loran antenna in the winglet. The loran antennas require a preamplifier right at the antenna. It turns out that the antenna is identical to their Com. antenna, and thats what I use it for. From: ponciroli@postoffice.worldnet.att.net Date: Fri, 18 Dec 1998 16:17:46 -0500 Subject: COZY: An elegant solution Dear Cozyites I have finished installing the internal rudder bellcranks, and would like to report that I believe that it is an elegant solution. In my opinion it is a safety improvement as well. When the aircraft is in the grazing position, the external bellcranks are at eye level for short guys like me. It gets rid of a '20 design and streamlines the rudder area beautifully. The plans are designed and sold by the Rutan folks. Date: Tue, 22 Dec 1998 22:54:50 +0200 From: Jannie Versfeld Subject: COZY: Winglets Dear all, Some advice please. The plans state to have the lower winglets with the under chamber inwards? Does it transition from under chamber out at the joint with the upper winglet to under chamber in at the lowest point? If so what about the fishtail if I reverse the template (I guess I have to make two then? ). Can I assume that I have to make the template with the fishtail in the reverse? Stupid questions but the plans aren't clear on this. Do I square off the trailing edge of the rudder and how thick? Kind regards, Jannie From: mikefly@juno.com Date: Tue, 22 Dec 1998 18:06:06 -0600 Subject: Re: COZY: Winglets >Some advice please. The plans state to have the lower winglets with >the >under chamber inwards? > >Does it transition from under chamber out at the joint with the >upper >winglet to under chamber in at the lowest point? Yes >If so what about the fishtail if I reverse the template (I guess I >have >to make two then? ). Can I assume that I have to make the template >with >the fishtail in the reversse> No. You will be using the template from the bottom of the upper winglet to make the top of the lower winglet. If the fish tails don't match then the cambers won't be right. Mike Bowden