From: "Doug Shepherd" Subject: COZY: Landing brake Date: Fri, 7 Jan 2000 19:47:33 -0800 Did the flange on anyone else's landing brake curl when you glassed the back side? The bondoed-on sticks kept the foam-backed portion flat but the flange curled pretty badly. I had to cut it back to 1/4" to get it to fit at all well into the recess. Now I have a big gap I'll have to fill with micro. I think I sanded too aggressively when I roughed it up for a good bond with the backside layup. On the plus side, I caught a near-mistake before I glassed the recess in the fuse. I hadn't excavated enough foam so that I could get the pin out of the hinge if I ever need to remove the brake. Doug Shepherd From: cdenk@ix.netcom.com Date: Sat, 8 Jan 2000 09:53:08 -0500 (EST) Subject: Re: COZY: Landing brake Was said There's a deeper problem: Why did it curl? The normal materials (epoxy and fiberglass) are in general very stable with repect to shrinkage or expansion during cure, which means the shape before cure is the shape after cure! Several possibilities: 1: (And not pointing fingers) the shape immediately before cure (after last touch with squeege or brush, or accidental bump) was curled. 2: Gravity before cure bent piece. 3: The epoxy, and I'm assuming the correct specified, approved material is being used, is defective and has a huge shrinkage or expansion factor. 4: The fiberglass is not a party to this situation. Diverging a little: Concrete slabs (flat on the earth) have a tendency to curl, the ends of a 20 foot long section may raise as much as 1/2". Just take a straightedge (usually at this stage of construction when this becomes evident there is a loose piece of electrical conduit) across a sawed (1/8" wide) joint in the concrete, I'll almost guarantee the ends of the conduit will be at least 1/4" high, and if you put a heavy load (forklift truck) on, it'll rock. The reason is different moisture content of the concrete top and bottom during curing. Also the larger stone pieces, the less shrinkage and curling, since there are less lines of portland cement which is the shinkage agent as the chemical bonding (reaction) takes place. Concrete DOES NOT dry, its a chemical raction like epoxy. From: "Doug Shepherd" Subject: COZY: Landing brake flange Date: Sat, 8 Jan 2000 08:20:40 -0800 Carl Denk said: > Why did it curl? As I said in the original post, I think it curled when I sanded the frontside layup too aggressively to be sure of a good bond. It got thin in a couple of spots and didn't support the new layup in the correct shape while it cured. But the sanding only aggravated the problem -- it had started to curl the minute I cut it out of the fuselage skin. I've never had problems with a layup being unstable, except when it's not backed up by foam. I had to redo my instrument panel stiffener because the unsupported portion of the wiring channel was pathetic. I made an actual channel out of foam scraps and the results were outstanding. The weight difference was at most a couple of ounces, my IP is very stiff and I have all kinds of space to apply sticky-backs for tie-wraps. I'm using MGS 285. It behaves well (and no smell!) and I think my work is decent. Either I haven't mastered the 'free-space' layup technique or it's just a bad idea. Doug Shepherd From: cdenk@ix.netcom.com Date: Sat, 8 Jan 2000 16:45:08 -0500 (EST) Subject: Re: COZY: Landing brake flange Was said Have also at times sanded too thin and wouldn't hold shape - Used scrap of wood, metal, etc. layer of duct (now days I have seen similar material called duck)tape as release and bondo, hot glue or otherwise hold in place, and then do next layup, possibly adding local fiberglass to ensure correct thickness. From: RhodenG@aol.com Date: Wed, 2 Feb 2000 08:23:04 EST Subject: COZY: main landing gear question This probably is in the plans somewhere but it escapes me.... What is the optimum distance between the center of the main landing gear attach points and the plane of the axle centers on the gear legs? Asked another way, if the waterline (WL) markings extended down the main gear legs, what would the WL be at the center of the axle attach point? Thanks, Greg From: "Hunter Welch" Subject: COZY: heat shields Date: Fri, 21 Apr 2000 23:07:21 -0400 Hello all, I have a simple question. Where are the heat shields mounted for the heat protection to the landing gear , when attaching the axle, wheel assy? Bill W From: cdenk@ix.netcom.com Date: Sat, 22 Apr 2000 07:42:26 -0400 (EDT) Subject: Re: COZY: heat shields On 04/21/00 23:07:21 you wrote: > >Hello all, > I have a simple question. Where are the heat shields mounted for the heat >protection to the landing gear , when attaching the axle, wheel assy? > Bill W > > They are against the fiberglass gear strut, with the axle outboard. They shield the heated disc from the strut. Mine are 1/8" alum., same diameter as the disc, cut out for brake caliper clearance, with fully worn pads. Mine are primed and painted with shiny aluminum paint to reflect heat. From: "Ed Richards" Subject: COZY: Re: heat shields Date: Sat, 22 Apr 2000 19:36:41 -0400 Hi Bill, I made mine from thin (.025" I think) shiny Aluminum sheet and have them clamped around the gear leg with one layer of Fiberfax between the Al and the glass. The shields cover the gear leg from the axle up about 4" (past top the brake disc). Ed Richards Cozy IV N826ER ----- Original Message ----- From: "Hunter Welch" To: Sent: Friday, April 21, 2000 11:07 PM Subject: COZY: heat shields > Hello all, > I have a simple question. Where are the heat shields mounted for the heat > protection to the landing gear , when attaching the axle, wheel assy? > Bill W > > Date: Sat, 29 Apr 2000 20:48:56 -0400 From: Neil & Margie Clayton Subject: COZY: Re: [c-a] Linear Actuators The one I used is an Elecktrak-1 Linear Motion actuator. It's made by Warner Electric (http://www.warnernet.com). I bought it via a local agent; Miller Bearings. Stroke is 4". 12volt. Internal limit switches at stroke ends. 75 lb max force. Yet to fly it, but works great in the shop. Price was about $175 delivered. Installation was a cinch. Noisy operation. Mail me if more info needed. Neil C At 09:29 AM 4/29/00 -0400, you wrote: >[The Canard Aviators's Mailing list] > >Can someone please post the supplier or suppliers for Linear Acturators used >for the speed brake?! Phone Number, Web Address any help is greatly >appreciated!! > >Thanks, > >RKH > > > > > \ >->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>-|- > / >-For details on sponsors of this list, copyrights, and how to remove >-yourself from this list, please visit: > > http://www.canard.com/canard-aviator-sponsors.html > > (c) 1997,1998, 1999 Canard Aviators. support@canard.com > / > -|-<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > \ From: "Nat Puffer" Subject: Re: COZY: Axle Drilling for Wheel Pants Date: Thu, 11 May 2000 09:17:06 -0500 Builders, You have two options when installing wheel pants. One is to drill and tap a hole in the end of the axle to fasten the pant to. But you have to drill it OFF-CENTER, because otherwise you will be drilling it through the cotter key hole, and you won't have a way to secure the nut from turning. The other option is to buy from Brock or make a U-shaped piece of steel which has a nutplate riveted to the bottom part of the U, and then weld the arms (legs?) of the U to the axle nut. This is a little more elaborate, but works best. If you drill and tap the axle off center, you must make sure that the depth of the threaded hole is deep enough to engage all the threads of the bolt. Uli Wolter did not do this and had the bolt fatigue at the threads which were exposed. Regards, Nat ---------- > From: Paul Stowitts > To: Cozy_Builders > Subject: COZY: Axle Drilling for Wheel Pants > Date: Thursday, May 11, 2000 12:33 AM > > Installing my wheel pants required drilling and tapping the axles. There > was already a centered hole to drill so I figured it would be relatively > easy even though the axles were already floxed and bolted to the main gear. > The drilling went well but my 10-32 tap decided it was time to break inside > the axle on the last turn. After many attempts to extract it, I decided my > time would best be utilized by replacing the axle. > > I recommend two things when it comes to axle drilling and tapping. One, do > it before you mount the axles as it is much easier. Two, use a 1/4-28 tap, > not a 10-32. > > Paul Stowitts > Cozy Mark Iv #200 > From: rlacour@pop1.trib.com Date: Thu, 11 May 2000 13:12:16 -0600 Subject: Re: COZY: Axle Drilling for Wheel Pants >Builders, > >>There is another easier way to install your wheel pants front screw The RV people sell a nut that replaces the hex nut on your axle, the hex nut the rv people sell is about 2 or 3 inchs long and has a nut plate already installed, it also has holes for the cotter pin,I used them on my cozy and they work really well cost is about 15 bucks a piece from Vans rick From: cdenk@ix.netcom.com Date: Thu, 11 May 2000 17:11:00 -0400 (EDT) Subject: Re: COZY: Axle Drilling for Wheel Pants I took a piece of 4130 steel, 1" wide, bent to a "U", and welded to the nut. Drilled the cotter hole through at the old hole location, and installed a floating nut plate on the axle centerline. Works just fine. From: jhocut@mindspring.com Date: Fri, 12 May 2000 07:20:11 -0400 Subject: Re: Re: COZY: Axle Drilling for Wheel Pants Carl, Any way you can post a photo of this for us who are imagination impaired. cdenk@ix.netcom.com wrote: > I took a piece of 4130 steel, 1" wide, bent to a "U", and welded to the nut. Drilled the cotter hole through at the old hole location, and installed a floating nut plate on the axle centerline. Works just fine. Date: Tue, 24 Oct 2000 17:43:08 -0500 From: David Domeier Subject: COZY: Brake chatter follow up.... Several weeks ago I reported a long standing problem of brake chatter (or shimmy) on roll out with the Cozy MKIV. A number of responses indicated that the problem could be wheels not balanced, toe in not correct, brake disks not true, or wheel halves not true. After an inordinate amount of time carefully checking things, this is what I have found. (all numbers are left and right respectively) Toe in was .4° and .6°. It is now .2° on both sides. (in landing attitude) A .020 shim will change toe in about .2°, and a .032 shim will change is about .4°. Tires were out of balance. In each case the valve stem was the heavy side. They are now statically balanced using as much as 1.5 oz of stick on lead. Disk run out is .002 and .008. (still is) Disk thickness is .365 +/- .003 on both sides. (still is) Installed new 10 ply retread tires thinking the resonant frequency of the spinning wheels and the "tuning fork strut" might change if that was a factor. Today I test flew the airplane. On take off and climb out, no vibration at all. On landing, with light braking, almost no vibration, On second landing, with heavy braking, the chatter developed but at a much lower speed (40 knots) and of less intensity than before. I still do not know what is causing it, but it is much better than before. If ever I solve the problem completely, I will report back. dd From: alwick@juno.com Date: Tue, 24 Oct 2000 16:54:15 -0700 Subject: Re: COZY: Brake chatter follow up.... Excellent report Dave. .008" tir runout is very high. Combined with your description, I'm confident that it is the primary cause. Make sure that the brake disk is properly mounted to wheel. No burrs, no radius interference, etc. Place .004" shim under low side and retest. I would not recommend using it shimmed for long period of time. Could induce warpage of disk due to uneven heat transfer (speculating here). On Tue, 24 Oct 2000 17:43:08 -0500 David Domeier writes: > Disk run out is .002 and .008. (still is) > ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj. From: "Doug Shepherd" Subject: COZY: Landing gear cover Date: Sat, 11 Nov 2000 17:15:59 -0800 How much clearance did people provide for the landing gear strut in the landing gear cover? I'm building mine and the instructions don't give any specific amount of relief to provide. Doug Shepherd From: "Nat Puffer" Subject: Re: COZY: Re: Landing gear cover Date: Sun, 12 Nov 2000 15:24:24 -0600 Builders, The recommended way to make the fairings where the strut joins the fuselage is to shape them with molding clay (Playdough), glass over with at least 2 plies, cut thru half way between where they join the strut and join the fuselage, then remove the gear, and dig out the clay, so that there is nothing but air inside the fairings. The cut has to be at least 1/8 inch wide to allow flexing of the gear to not cause cracking of the fairing. I have tried other ways, but this way works the best, doesn't cost much, and is easy to do. This should be done while the fuselage is upside down. Then when it is sitting on the gear, the fairing halves won't be quite aligned, but in the air with the weight off the gear, the halves will be aligned for minimum drag. Regards, Nat ---------- > From: Ed Richards > To: Cozy Builders List > Subject: COZY: Re: Landing gear cover > Date: Sunday, November 12, 2000 3:40 PM > > Doug, > The clearance issue is not so much around the gear cover but more a question > or how do you fair the strut into the fuselage and leave the right amount of > clearance. This was a spot in the plans that I found particularly confusing > because no direction is given. And if you look at finished Cozies you'll > see quite a variety because it's not really specified. > > I had someone make, what I thought was, a good suggestion and that is to > create a space between the gear strut and the end of the fairing that could > be filled with RTV. This would make sort of a flex joint and eliminate the > micro that cracks off the first time land a little hard. While I haven't > done this yet, although I plan to at some point. I think this would also > work well where the wheel pants join the gear strut. > > My $.02. Hope it helps. > > Ed Richards > Cozy IV N826ER > > > > ----- Original Message ----- > From: "Doug Shepherd" > To: "Cozy mailing list" > Sent: Saturday, November 11, 2000 8:15 PM > Subject: COZY: Landing gear cover > > > > How much clearance did people provide for the landing gear strut in the > > landing gear cover? I'm building mine and the instructions don't give any > > specific amount of relief to provide. > > > > Doug Shepherd > > > > > > > From: "Ed Richards" Subject: COZY: Re: Landing gear cover Date: Sun, 12 Nov 2000 16:40:52 -0500 Doug, The clearance issue is not so much around the gear cover but more a question or how do you fair the strut into the fuselage and leave the right amount of clearance. This was a spot in the plans that I found particularly confusing because no direction is given. And if you look at finished Cozies you'll see quite a variety because it's not really specified. I had someone make, what I thought was, a good suggestion and that is to create a space between the gear strut and the end of the fairing that could be filled with RTV. This would make sort of a flex joint and eliminate the micro that cracks off the first time land a little hard. While I haven't done this yet, although I plan to at some point. I think this would also work well where the wheel pants join the gear strut. My $.02. Hope it helps. Ed Richards Cozy IV N826ER ----- Original Message ----- From: "Doug Shepherd" To: "Cozy mailing list" Sent: Saturday, November 11, 2000 8:15 PM Subject: COZY: Landing gear cover > How much clearance did people provide for the landing gear strut in the > landing gear cover? I'm building mine and the instructions don't give any > specific amount of relief to provide. > > Doug Shepherd > > > Date: Sun, 12 Nov 2000 17:04:40 -0600 From: David Domeier Subject: Re: COZY: Stainless brake lines Carl, You thinking about changing to SS? How are you going to see the little bubbles go up when bleeding the brakes? Burt knew what he was doing when selecting Nylaflow. Kidding aside, AN3 or maybe AN2, 303 hose ought to work just fine. I think the certified guys use AN4 like on a Cessna. dd Date: Sun, 12 Nov 2000 17:15:40 -0600 From: David Domeier Subject: Re: COZY: Re: Landing gear cover Doug, If you asking about the door that goes between the strut legs on the bottom of the fuselage, I can tell you what I did. At first the clearance was not enough. The strut flexed enough on one my less than sterling landings and it came down far enough to crack the door. It did not come off but a couple screw holes got enlarged. I remover the inside glass on the door and removed some more foam and reglassed it and what I have now is enough room for the strut to move up and down a bit. I would say give it at least a 1/2 inch clearance. The strut (mine is an Aerocad) moves more than you'd think. dd Date: Sun, 12 Nov 2000 21:17:59 -0500 From: Carl Denk Subject: Re: COZY: Re: Landing gear cover Mine are glued to the fuselage with white RTV. In 850 hours, I think I had to reglue them 2 or 3 times. Date: Sat, 11 Nov 2000 18:17:37 -0600 From: David Domeier Subject: COZY: Cozy cruisin' - brake chatter no more.. A while back I reported a brake chatter problem since day one on my airplane, a Cozy MKIV, and was trying to cure it. Many of you reported having a similar problem. >From the responses, it would appear this annoying problem is caused by a number of factors. Some found excessive toe in caused it, some found wheel balance a culprit, some found wheel machining not true and others excessive disk run out (warp) the cause. I think I had a combination of all plus one more because as I addressed each possible fix, starting with the least expensive first, the problem diminished but never went away completely. The one possible cause not mentioned by any builder was suggested by a tech rep at Cleveland Brakes. She said it was possible that the rigid plastic brake line was causing the anchor bolt to hang up in the torque plate. This has happened in some applications and the symptoms are brake chatter on roll out. It also causes excessive wear of the bushing in the torque plate. At her suggestion, I had 2 303 hoses made up with AN3 fittings and connected them between the plastic line and the brake unit. (Note: one of my plastic lines was in fact causing some binding in the brake assembly. I cured it by adjusting the 90° fitting at the brake, but I still had the chatter on roll out. The installation of the hoses reduced the the chatter to an almost acceptable level, but it was still there) Last evening, a friendly UPS guy dropped off a set of new disks I had ordered about 2 weeks ago. After dinner I went to the hangar and installed the new disks in about 35 minutes. (I'm getting pretty fast at this having had the wheels off about 6 times recently.) I am pleased to report I flew the airplane today and for the first time since it was born, there was no brake chatter on roll out. The only vibration noticeable was friendly Lycoming stuff. The disks (part 164-08500) have about 350 landings and were worn somewhat. They also had a run out of .004 to 008. Evidently it is too much for this application. Some of you reported .003 is too much and you are right. My next step is to remove the hoses and go back to the plastic lines. (I did not cut them) I will report the results. If in fact the plastic lines are a factor, it will be an interesting challenge to find room for the hoses under the wheel pants. Thanks to all for the input. dd Date: Sun, 12 Nov 2000 14:12:27 -0600 From: David Domeier Subject: COZY: Cozy cruisin' - brake chatter no more... re "My next step is to remove the hoses and go back to the plastic lines. (I did not cut them) I will report the results." (flex lines installed at the brakes by recommendation of Cleveland) The 303 AN3 hoses were removed this morning, the brakes bled one more time, and a flight check proved the system to be OK without the flex hose as recommended by Cleveland. I do believe, however, the rigid Nylaflow tubing we use as brake fluid line could cause anchor bolt/torque plate binding if it is a bit short at the brake or tie wrapped to the strut. As per usual, the Cozy performed just dandy. I was alone in the traffic pattern for a rare change of pace so two close in full stops were accomplished with just .2 logged on the hobbs. This airplane is a delight to fly - once airborne, accelerate to 120kts, a tight climbing turn to down wind, gear down, power to idle and a 180° turn to touch down. Works great if there aren't any Cessna's dragging in a 3 mile final at 65 knots after a cross country around pattern. dd Date: Thu, 21 Dec 2000 09:32:46 -0600 From: David Domeier Subject: COZY: Brake Chatter/Newsletter #72 The BRAKE CHATTER write up in newsletter #72 needs clarifying. There were numerous progress reports and exchanges of ideas regarding a solution to brake chatter on my airplane. It is no wonder the sequence of finally solving the problem, as stated in #72, is out of sequence. There was, in my opinion, more than one cause of the problem. (wheel alignment, tire balance, right brake binding due to restricted plastic line and finally disk run out) As I corrected each item the chatter lessened somewhat, but never did go away completely until the last and most expensive fix was accomplished - installing new stainless disks. When that was done, I still had the AN303 hoses in the system and hoped that going back to original plastic would not reintroduce the problem. It did not. Plastic is OK as long as the line in not tie wrapped to the strut. The original disks (part 164-08500) have about 350 landings and were worn somewhat with a run out of .004 to 008. Without any doubt in my mind, that much run out is too much. But brake chatter, which is relatively common in these airplanes, can be caused by other factors. Do not go out and buy new disks until the wheels are properly aligned, balanced, and the anchor bolt is checked for free movement in the torque plate. dd