From: ernie de goveia Subject: COZY: South African Oaf Date: Mon, 15 Mar 1999 15:05:09 +0200 Hi All I am building a cozy 3, right wing, top spar cap,ply 4. I'm using ciba geigy LY5052 resin, I've used it for years. This resin has a 2 hour pot life , last week I exceeded that on the top spar cap. The area of the spar cap from bl23 to bl55 is much too dry , I did scrape as much of the sticky goo of as was possible and did put fresh resin onto it, it did help but not enough. The problem now , is the repair. I assume three options: 1) leave as is - even I dont think this is advisable. 2) Grind off the 4th ply from bl23 to bl55 and replace this section only. Any ideas? 3) Grind off the whole of the 4th ply and replace. this is probably the only option, the problem is not to grind, it is to grind to a set depth. Any ideas on how to measure this? I would appreciate any help to get out of this hole Thanks in advance Ernie the South African Oaf Still in Cape Town Date: Wed, 17 Mar 1999 06:53:14 +0200 From: Jannie Versfeld Subject: COZY: Aileron Cutout Gaps Hi Coziers, Can any one tell me what is the reason that the inboard and outboard aileron cut-out is 90 degrees to the trailing edge and not parallel to the center line of the aircraft? It only seems that it may have less interference drag if in line with aircraft tracking? Kind regards, Jannie Verfseld #673 "Completed wing core cutting" Date: Tue, 16 Mar 1999 22:04:39 -0800 From: "LCDR James D. Newman" Subject: COZY: Re: Aileron Cutout Gaps Hi Jannie and All, > Can any one tell me what is the reason that the inboard and outboard aileron cut-out is 90 degrees > to the trailing edge and not parallel to the center line of the aircraft? Ease of building. I made my inboard and outboard aileron cuts parallel to flight. Boy what a geometry alignment problem I had to figure out to get the gaps to be close yet allow full travel. The cuts end up being canted. If you don't get it just right, you'll restrict and / or bind the ailerons. It's very doable, and looks nice when done, but is a lot of work. If you're going to do it or think you want to do it, practice the concept on a short section of wing (sweep, airfoil shape and all) - you'll be very glad you did [ I wish I had practiced first :-) ]! Either way you do it, still close off the cup on each end of the ailerons, particularly if you keep the cut perpendicular to the trailing edge per plans. The race boys claim a little more speed. > It only seems that it may have less interference drag if in line with aircraft tracking? True, that's why I went through all the trouble. Looks kinda snarky (haven't heard this one in a while) too. Infinity's Forever, JD Date: Wed, 17 Mar 1999 08:05:47 +0200 From: "Rego Burger" Subject: COZY: Aileron Cutout Gaps Burt did it like that so Nat kept the idea to keep it simple ( Kis ) When correctly finished with silicone between the gaps there is little or no significant drag. I can't see any major problem changing it other than matching the cowling to fit..this translates to time and money. Naturally you would need to make your own cowling as the std. one available will not fit. Rego Burger Port Elizabeth RSA Date: Wed, 17 Mar 1999 08:15:53 +0200 From: "Rego Burger" Subject: COZY: Aileron Cutout Gaps Sorry about previous reading... I was thinking of the match between wing and cowling.....( also 90 deg to attach points ) I'm working at this thought while designing my cowling, hence the similar thought on lines = airflow.... :-) Back to the subject. ( sigh ) The aileron cutout must be at 90 deg. to "work" with minimum gaps as the hinge motion is 90 deg to the trailing edge.... if you cut it to follow the flow of the air the rotation of the aileron will place a "twist" and this would catch if you have a small gap between aileron and wing.... if you increase this gap to make it work it a.) does not look neat and b.) the gap would create drag. Rego Burger RSA Sounds like you'll be flying before me at the pace you're working... :-) From: Epplin John A Subject: RE: COZY: Aileron Cutout Gaps Date: Wed, 17 Mar 1999 07:51:33 -0600 If you really look at this I believe the cuts should be made 90 deg. to the hinge line. This will allow minimum gap without interference. Also keep in mind there is some flex in the wing, make sure you allow sufficient clearance. I would be concerned with anything less than 1/16 inch, even that may not be enough. I say this not having flown mine yet, hope someone with real life experience either corrects me or confirms my observation. John Epplin Mk4 #467 N100EP, applied for. > -----Original Message----- > From: Jannie Versfeld [SMTP:qmain@intekom.co.za] > Sent: Tuesday, March 16, 1999 10:53 PM > To: cozy_builders@canard.com > Subject: COZY: Aileron Cutout Gaps > > Hi Coziers, > > Can any one tell me what is the reason that the inboard and outboard > aileron cut-out is 90 degrees to the trailing edge and not parallel to > the center line of the aircraft? > > It only seems that it may have less interference drag if in line with > aircraft tracking? > > Kind regards, > Jannie Verfseld #673 "Completed wing core cutting" Date: Wed, 17 Mar 1999 08:00 -0600 (CST) From: Michael Pollock Subject: Re: COZY: Aileron Cutout Gaps Jannie Versfeld wrote: >Can any one tell me what is the reason that the inboard and outboard >aileron cut-out is 90 degrees to the trailing edge and not parallel to >the center line of the aircraft? >It only seems that it may have less interference drag if in line with >aircraft tracking? Drag is not a problem during cruise if you have your airplane properly configured. It also makes it easier for fabrication when they are 90 degrees. Our Velocity is also at 90 degrees. Michael.Pollock@mci.com Flying Velocity N173DT Building Cozy MKIV #643 Date: Sun, 11 Apr 1999 17:40:45 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: Wing "Kink". Hi Jannie and All, > >> Jannie Versfeld Writes: > >> Just pulled my right wing from the jig and to my horror I saw a "Kink" in the trailing edge? > It is where the middle panel and the inner panel joins. Did I do something wrong? > Phil Johnson wrote: > If I read you correctly your trailing edge takes a dip at about the > inboard location of the aileron. If this is the case, you have built it > correctly. Look at the location of the trailing edge according to the > jigs and you will see what I mean. The aero canard design uses a > straight edge all the way in to the cowling and is different to Nat's > design. Both seem to work. > Dave Domeier wrote: > Sounds to me like you have a perfectly normal Nat Puffer MKIV wing. The way I understand it, the reason the Long-EZ (LE) wing has ~+0.6 degrees of wash-in (trailing edge down) at the beginning of the ailerons is because of the interaction of the canard tip vortices (which can reach to about 30" in diameter) with the wing and strake at that juncture. Then the wing twists trailing edge up from that point to -2.7 degrees of wash-out (trailing edge up) at the wing tip to make sure the wing tip stalls last (like most all other airplanes do). The reason (TWIUT) for the "kink" in the trailing edge of the wing at the end of the strake and at the beginning of the aileron sloping up and slightly forward to the cowling is left over from the Vari-EZE (VE) days. Since the strakes are basically non flying, and Burt didn't want to make a new cowling when he changed the Vari-EZE to a Long-EZ, he made the LE wing trailing edge slope up and forward to the VE cowling (about 0.99" up and about 0.67" forward compared to if you just make the wing trailing edge straight to the cowling). I told Shirl Dickey this tid bit in Nov. '85 (and other items), and to many others since then, the rest is history (some LE derivatives make straight trailing edges to the cowling, some don't) :-) . So, straight trailing edges or kinked, both work fine - depends on whose LE derivative you have and whose cowling you buy, or if you make your own cowling (which I prefer). Personally, it's a little easier to blend and contour the wing when sanding if the trailing edge is straight, but I wouldn't go through the trouble to change your templates if that's not how your derivative has it already. HTH. Infinity's Forever, JD Date: Sat, 10 Jul 1999 12:27:50 -0500 From: Bulent Aliev Subject: COZY: Re: Sanding wing cores to template > > > -------> So then, is it really worth it to hotwire to 1/8" oversize, > then sand down to contour? I debated on doing this for the canard. I > wish I had done it too. Did you find the wing foam easy to sand with > straight consistency? > > Wayne Hicks Absolutely! I had a chance to compare cores done both ways and I like mine better. No grooves here and there, No lag dips etc. The most you will appreciate this method is at the winglets. The guy at the top of the core must move the hot wire about 3 times slower and the wire burns in nasty grooves. My cores looked like came from a mold. First I made all per plans templates from aluminum sheet. Then traced them loosely 1/8 or 1/4" oversize on top of (any cheep material will do) the thin particle board. Transfer the WL, hot wire guide numbers and match drill all the holes for the sheet metal screws - the more the better. Cut your cores with the oversize templates. You will wary much less about mistakes. Screw in to the same holes the real al. templates and use at least 6' sanding board. I made mine from 2"X3" aluminum extrusion and self adhesive 36 grit sand paper. make sure it sticks good, or loose paper will make grooves in the foam. start sanding trying to do your best to keep the board between the matching numbers on each template similar to the hot wire. When you get close and start touching the template you will hear it. Then do your final tune up until you are satisfied. While there, hot wire your spar cap channels . Do not try to sand them. It is not worth it. Bulent Date: Mon, 12 Jul 1999 16:57:30 -0500 (CDT) From: Tom Brusehaver Subject: COZY: Wing drilling I tried to drill my wings over the weekend. I am not too happy, it seems the darn top hole in the outboard part of the wing is too low. I'll have to dig out some more foam in the access hole to put a nut on. The bottom was more flush than the top, so I don't think I did things too wrong. How did anyone else do? I broke three of the points off the spot facer. This was a new one I bought just for the wings. I was about 1/4" on one hole (I was rotating between holes trying to keep things cool). I remember folks recommending a hole saw, but when I went to all the stores, the smallest hole saw anyone had was 3/4". I have the 1/4" holes all matched drilled, but I had to take everything apart, since I didn't have room to leave things, and I was uncomfortable with the tool and hole situation. Is there a better tool to drill things? I have the MSC catalog and they seem to have a nice assortment of hole cutting tools. Am I too far off with that top hole in the wing, will I be better off moving that up, or dropping the wing tip down? From: ponciroli@postoffice.worldnet.att.net Date: Tue, 13 Jul 1999 07:38:56 -0400 Subject: Re: COZY: Wing drilling Dear Tom and fellow builders Tom wrote: I tried to drill my wings over the weekend. I am not too happy... After visiting Marc Zeitlin and listening to his story on wing drilling, my building partner and I agreed that drilling the holes with a spot facing tool was not the optimum way to do the job. First it just aint the right tool for the job, it causes too much heat when cutting and the finish isn't crisp. Sorry Nat, so here's how we did it. We aligned both wings and main spar to the correct incidence and leveled both fore and aft and from, side to side. We then bondo puttied them together. Then we used large clamping straps to hold every thing together when drilling. We drilled 1/4 inch pilot holes and then we drilled the bolt holes with the proper sized drill ( i think it was a 1/2 inch bit) with a low speed 1/2 inch chucked Milwaukee drill. When the drill point started to show through the opposite side, we then finished off the job with the spot facing tool. All holes were drilled within one hour and the work site didn't get over heated. Hope this helps. Don Ponciroli ponciroli@att.net From: Epplin John A Subject: RE: COZY: Wing drilling Date: Tue, 13 Jul 1999 09:07:54 -0500 > -----Original Message----- > From: Tom Brusehaver [SMTP:tgb@wamnet.com] > Sent: Monday, July 12, 1999 4:58 PM > To: cozy_builders@canard.com > Subject: COZY: Wing drilling > > > > Is there a better tool to drill things? I have the MSC catalog and > they seem to have a nice assortment of hole cutting tools. > > [Epplin John A] MSC has several hole saws, 5/8 if I remember correctly. This works much better than a spot facer. The only thing to watch out for is they will cut a slightly larger hole than nominal. I made a template with the correct spacing of the holes, template outside dimensions same as spar rear face. Attach template to rear face of spar, align with tip and bottom edge, and drill through with pilot drill. I think I used 1/8 in or so to locate the holes. Move template to forward face, and drill pilot holes there. At this time check for proper bolt head clearance, if not correct you can elongate these holes somewhat to get where you need to be. I then through drilled with 1/4 in long drill. You will need to open up the forward holes 5/8 with your hole saw. Mount the wing and bond, clamp, glue, whatever is needed to guarantee it will stay put. Check alignment about 5 times. When satisfied, make a bushing to fit the 5/8 hole in the front face of the spar with a 1/4 hole centered in it. I made mine from aluminum, anything will work, probable even wood. Drill through the wing mounting points with 1/4 in long drill. Remove the pilot drill from the hole saw and insert a piece of 1/4 in drill rod about a foot long. You will need to grind a flat on this to hold the hole saw torque. Use the drill rod for the pilot, it will not ream the 1/4 in hole you already have and make a larger hole. I used an air driven drill to drive the hole saw, not really required but they have lower inertia in case the saw binds. I takes a few minutes for each hole, go slowly and remove the hole saw and remove the stuff, there are several layers of aluminum and glass to go through. I cut mine dry, don't know if water lube would be better or not. I reamed these holes after the hole saw with a 5/8 in adjustable reamer set so as to true up all the holes to the same size. This will be a few thousandths over 5/8. I then made the bushings about .005 under the reamed holes with 3/8 holes instead of the 1/2 called for in the plans. Break the wings free and install the bushings and bolt the wings on with 3/8 in bolts. When satisfied that all is well, remove one bolt and get a long 15/32 drill and drill the hole out. I think I made another bushing to hold the drill straight. I then line reamed with a .500 reamer which I extended with a piece of tubing over the shank. I don't remember the exact ID of the tube, need to check your reamer. I ended up drilling through the tube and reamer and using a rivet to hold it together. When the first one is done, install a AN8- whatever bolt. If you don't use a AN bolt you should check the hardware store bolt for size, they are usually quite a bit under size. Continue on with the other holes. Debur the best you can, I made a special tool to do that with but think it was a waste of time. You will like the way this all goes together later as you will mount and remove the wings abut 8 thousand times before you are flying. John Epplin. Mk4 #467 > Date: Tue, 13 Jul 1999 15:00:36 -0400 From: Neil Clayton Subject: RE: COZY: Wing drilling >> Is there a better tool to drill things? I haven't drilled my wings yet, but it's a similar problem to drilling the bores for the canard attach tabs, and the main gear mounting points. I took a hole drill, which left to itself would drill oversize, & mounted it on a 1/4" dia x 12" long piece of drillrod. I centred the hole drill by eye as best I could, then mounted it on the lathe and using the tool as a static guide, rotated the piece by hand bending the teeth in or out with plyers 'till I got a fairly good 5/8 circle, concentric with the drillrod. Then I took a final skim with the lathe tool - result; a very nice accurate 5/8" hole. Neil C. From: cdenk@ix.netcom.com Date: Tue, 13 Jul 1999 16:16:12 -0500 (CDT) Subject: Re: COZY: Wing drilling I think I would go slightly undersize on the drill, and ream if doing it today. Date: Wed, 14 Jul 1999 10:04:22 -0700 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: Wing drilling Tom Brusehaver wrote: "I tried to drill my wings over the weekend. I am not too happy, it seems the darn top hole in the outboard part of the wing is too low. I'll have to dig out some more foam in the access hole to put a nut on. The bottom was more flush than the top, so I don't think I did things too wrong. How did anyone else do? I broke three of the points off the spot facer. This was a new one I bought just for the wings. I was about 1/4" on one hole (I was rotating between holes trying to keep things cool). I remember folks recommending a hole saw, but when I went to all the stores, the smallest hole saw anyone had was 3/4". I have the 1/4" holes all matched drilled, but I had to take everything apart, since I didn't have room to leave things, and I was uncomfortable with the tool and hole situation. Is there a better tool to drill things? I have the MSC catalog and they seem to have a nice assortment of hole cutting tools. Am I too far off with that top hole in the wing, will I be better off moving that up, or dropping the wing tip down? " Tom, Not to belabor the point, but this was ALSO thoroughly covered in CP. I elected to drill all mine with the spot facer, but (per CP recommendation), I used a LOT of water spray to keep things nice and cool. Didn't take too long. No damage to the tool, and I can still use it, because it is still sharp. Another issue, heat-wise, is how hot the layup gets. It can not only change dimension, but the high temps can deform the epoxy-glass matrix, and possibly weaken it. Water works great, and won't hurt anything. As for the location of one of your holes, I don't quite visualize the problem from the description. Could you elaborate? My first knee-jerk response, based on my sketchy visualization, would only be concerned about where the hole you drilled passes through the imbedded aluminum pieces in the layup. If your hole has come too close to an aluminum edge, you could have a serious problem. Have you only drilled a 1/4 pilot hole there, or have you punched the large diameter hole through yet? If only a pilot hole, I would reccommend filling it with 5-minute and flox, and starting over, so long as the large diameter hole completely encompasses the *old* pilot hole. I don't understand your comment about dropping the wing tip down, but that makes no sense to me. The wing is where it should be (hopefully), and should not move while you are drilling your holes. It's position is "not negotiable". -Howard Rogers Date: Wed, 14 Jul 1999 13:18:11 -0500 (CDT) From: Tom Brusehaver Subject: Re: COZY: Wing drilling >visualize the problem from the description. Could you elaborate? My first >knee-jerk response, based on my sketchy visualization, would only be >concerned about where the hole you drilled passes through the imbedded >aluminum pieces in the layup. If your hole has come too close to an >aluminum edge, you could have a serious problem. Have you only drilled a >1/4 pilot hole there, or have you punched the large diameter hole through >yet? If only a pilot hole, I would reccommend filling it with 5-minute and >flox, and starting over, so long as the large diameter hole completely >encompasses the *old* pilot hole. I don't understand your comment about >dropping the wing tip down, but that makes no sense to me. The wing is >where it should be (hopefully), and should not move while you are drilling >your holes. It's position is "not negotiable". The holes in the spar are correct according to the plans, but if I level the wings horizontally, the outboard holes are maybe 1/4" too low in the top, meaning in the access hole, I'd have to dig down a little to put a nut on. My choices are; *move the top hole up 1/4" in the spar (sort of recommended by Nat.) *move the wingtip down, and drill all the wing holes in the same place as the spar, centering in the aluminium. (if dihedral is supposed to be good for canard, maybe anhedral is good for wings?). *carve out the access hole a little. *probably others. Redrilling should be no problem, since I only have the 1/4" holes, and I could easily cover them with the 5/8" hole I'll probably wait until after Oshkosh do do anymore on the wings now. Date: Wed, 14 Jul 1999 23:36:04 -0500 From: Kent Ashton Subject: Re: COZY: Wing drilling > Tom Brusehaver wrote: > "I tried to drill my wings over the weekend. I am not too happy, it > seems the darn top hole in the outboard part of the wing is too > low. I'll have to dig out some more foam in the access hole to put a > nut on. The bottom was more flush than the top, so I don't think I > did things too wrong. How did anyone else do? > I had a similar problem. My 1/4" hole was off center, but I pluged it with a piece of 1/4" 2024 rod and was able to redrill it in the the right place. When I drilled it out to full size, it also drilled out the plugged area. I'm not sure what you're using to drill the big holes, but I suggest buying an "aircraft counterbore". It's has a straight shank and looks like a short end-mill on the end of it with a 1/4" pilot hole through it. I cut most of the shank off with a metal chop saw so it was about 2" long and put a 1/4" rod in it. It cut very cleanly and quickly with little heating of the inserts. The big machine tool catalogs list them. --Kent Ashton Date: Thu, 15 Jul 1999 08:32:53 -0500 (CDT) From: Tom Brusehaver Subject: Re: COZY: Wing drilling This is what I think I did wrong in drilling my wings; I looked at Chapter 19 page 9, Figure 54, where it showed the inboard hole to be 1.75 inches from the top of the spar. The outboard holes are 1.2" from bottom, and top 4.2" from there. I accepted those values, as they were presented. Last night I did some more digging. In chapter 14, page 5, the section shows top holes at WL20.5 (inboard and outboard), and the bottom holes at WL16.3 (4.2 difference). It also shows the spar at ~6.3 inchces thick at the forward face. My spar is almost 6.8" at the forward face. I did extend the sparcaps farther out, making them thicker. Measuring, the thickness, well, it is hard to be too exact, but it appears the top cap is maybe .18 thicker than the drawing, the bottom is maybe .12 thicker. Also on chapter19 page 12 section B-B which is labeled "full size", it shows the bolt centered ~1.25 from the top and bottom. What I think I'll do, is fill all the holes, and start over. I'll mark a constant waterline on the aft face of the center spar, and make all the measurements from there. Date: Thu, 15 Jul 1999 09:56:35 -0400 From: "Johnson, Phillip" Subject: Re: COZY: Wing drilling Tom Brusehaver Writes> My spar is almost 6.8" at the forward face. < Tom when you are referring to the thickness are you referring to the height of the spar. I did mine so long ago I can't remember the dimensions. If your spar is thicker/higher than the spec it will not match the wing thickness and you will end up with a significant bump in the transition from the spar to the wing. Be careful, and now is the time to fix it if it is in error. Good Luck Phillip Johnson Date: Mon, 12 Jul 1999 10:32:54 +0200 From: "Rego Burger" Subject: COZY: Sanding wing cores to template Methods are free to differ if they achieve the same results. Some like sanding, some don't. I found slow cutting ( hot wire ) gave better results with the hotwire temp. set to move at 2-3 seconds per inch. After all there is no rush. The amount of troughs I had were minimal and micro fixes it quick. Régo Burger RSA From: Epplin John A Subject: RE: COZY: Sanding wing cores to template Date: Mon, 12 Jul 1999 09:57:11 -0500 > Subject: Re: COZY: Sanding wing cores to template > > > I made two sets of templates, easy to do with a laser cutter. One .032 oversize. Match drilled allignment holes and nail holes. Hot wired using the oversize then removed them and installed the on-size templates. Sanded down to the on-size using a long aluminum I beam with coarse paper glued to it. I placed the cores in the cutouts for the sanding operation. Only leaving .032 in. was almost a mistake. I removed verry little foam and in places none. Still had ot add a small amount of micro a few places. I did not do this with the winglet templates, made those straight forwared. There is a considerable amount of micro in the top area of the winglets. If I had it to do over again I would make two sets of templates for the winglets also, about .125 oversize on the top end, maybe only .062 on the lower end. Don't know what difference it would make but this would reduce the sanding to a minimum. If I remade the wing templates I would go to .050 or more oversize. John epplin Mk4 #467, getting ready to prime these super straight wings! From: cdenk@ix.netcom.com Date: Mon, 12 Jul 1999 15:54:57 -0500 (CDT) Subject: Re: COZY: Sanding wing cores to template On 07/12/99 09:41:08 you wrote: > >Rego, > > > re "Methods are free to differ if they achieve the same results. >Some like sanding, some don't." > > Me thinks likewise, however, IT IS infinitly easier to sand the foam >core than micro fill. The smoother and straighter the core, the less >fill will be required later.... > >dd > > > And lighter weight. From: cdenk@ix.netcom.com Date: Mon, 12 Jul 1999 16:08:18 -0500 (CDT) Subject: Re: COZY: Sanding wing cores to template When cutting the wing and canard cores, use mixing sticks (with 2 nail holes) to temporarily continue straight over the spar cap troughs. Then remove the sticks and cut out the troughs as a separate operation. Presto no wire lag problems, nice neat corners. Date: Mon, 12 Jul 1999 16:48:38 -0500 (CDT) From: Tom Brusehaver Subject: Re: COZY: Sanding wing cores to template >When cutting the wing and canard cores, use mixing sticks (with 2 >nail holes) to temporarily continue straight over the spar cap >troughs. Then remove the sticks and cut out the troughs as a separate >operation. Presto no wire lag problems, nice neat corners. Thanks alot Carl, I just finished my wings. :-/ What a great idea, dang, I wished someone had suggested that two months ago. Actually, I only had one trough kinda rounded. From: cdenk@ix.netcom.com Date: Tue, 13 Jul 1999 16:29:21 -0500 (CDT) Subject: Re: COZY: Sanding wing cores to template Yea. Mine were cut to the plans template with borrowed templates, a few (4 or less) very light strokes with a 4 foot very hard , very straight, very old oak sanding board with 80 grit glued to it to knock off nubbins. Very little filler. I think they are along with the straightest of wings around. Everyone trying to make more work, instead of planning, and patience. Date: Wed, 14 Jul 1999 09:46:23 -0700 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: Sanding wing cores to template >>When cutting the wing and canard cores, use mixing sticks (with 2 >>nail holes) to temporarily continue straight over the spar cap >>troughs. Then remove the sticks and cut out the troughs as a separate >>operation. Presto no wire lag problems, nice neat corners. > >Thanks alot Carl, I just finished my wings. :-/ > >What a great idea, dang, I wished someone had suggested that two >months ago. Actually, I only had one trough kinda rounded. This is one area that continues to astound me. I first heard about this idea in Canard Pusher MANY years ago. The CPs should be considered required reading for anyone building one of these type airplanes. I can't think of another place, with the possible exception of the Central Sates newsletters, more chock full of useful, on-topic, and safety-related information specifically relating to Canard Pushers. It certainly isn't all dry, techincal stuff, either. There is a lot of human interest content, many great tips and how-to articles, and a wonderful, rich history of this whole phenomenon. Do whatever it takes to get your hands on the whole set! --Howard Rogers Date: Wed, 14 Jul 1999 15:41:50 -0400 From: "Johnson, Phillip" Subject: COZY: RE: Wing drilling Tom Brusehaver writes >The holes in the spar are correct according to the plans, < Tom if you would have to dig into the foam to allow the nut to be tightened then it suggests that your holes are too low and that you have misread the plans. My recommendation is to re-look at the plans and check the measurements yet again. 1) If your measurements are incorrect then make the appropriate adjustments; or, 2) if the measurements are correct then move the hole up 1/4 of an inch as Nat suggests. I think that the former is the case since there should be ample clearance around those nuts if the it is built to plans. Good Luck Phillip Johnson Date: Sat, 10 Jul 1999 23:01:38 -0600 From: James Russell Subject: Re: COZY: Re: Sanding wing cores to template >Was questioned > >I did exact size, and had ZERO problems, using a variety of helpers. Used >wife for canard, 5 minutes instructing, and they >were perfect, and my wife never even watched hotwire before, she is much >more at home with kitchen and sewing machine. > >I would think trying to sand to an accurate surface would be difficult. >How do you hold the piece to witstand the sanding >force and yet not distort the piece. Maybe one side nested in the scrap >piece would work, but turn it over, it no longer nests >snuggly since mating surface has been removed. > >There has been a zillion planes built using actual size templates. If >having problem with quality, need to review technique. >Much planning, and preparation for a 5 minute cut. Hi all: I agree w/ cut-to-size plan... I was building drone prototypes and the engineer over the wing shop (straight out of college) wanted us to sand down the cores ( 36" span). Well, his tolerance was .030" and how we were to measure, let alone acheive this goal is still a mystery. You hold the core in flight position and it would deflect 1-2"... Plus the parts tapered (in chord) so at the tips we had valleys, etc. To get good, light finished parts you have to have perfect cores. That means burning up alot of foam if necessary. This fellow, who is very smart, also believed in wooden surface plates... Then there is the infamous discussion about: "This elevon core is 1/64" oversize! The skin won't fit!" "What skin?" "The 1/64 plywood skin!" "Show me on the print where the skin is..." "I can't draw a 1/64" skin!" "If you can't draw it, how am I supposed to build it?" Well, it was a good education... Regards, James Date: Sun, 11 Jul 1999 16:55:48 -0700 From: Stet Elliott Subject: COZY: Re: [c-a] Re: Sanding wing cores to template Bulent Aliev wrote: > [The Canard Aviators's Mailing list] > > > > -------> So then, is it really worth it to hotwire to 1/8" oversize, > > then sand down to contour? I debated on doing this for the canard. I > > wish I had done it too. Did you find the wing foam easy to sand with > > straight consistency? > > > > Wayne Hicks > I agree with Bulent that hotwiring oversize and sanding to contour is a very good idea. I didn't use this technique on my wings and wished I had. I did on my winglets and was very pleased with the result. Hotwiring oversize and sanding to contour would be particularly helpful when jigging the wing cores together for microing. If the cores are perfect, the use of long straight-edges make aligning the cores a snap. But if your cores are undercut in some areas due to burn-in or wire lag, you often can't tell when straight is really straight, (i.e., no truly straight reference line on the cores.) Makes things terribly befuddling! Whichever technique you use, make SURE that your cores are dead nuts true along the aileron and rudder hinge lines. The trueness of your cores in this area directly determine how straight the hinge lines will eventually be. If your cores aren't true along the hinge lines, your hinges will be out of alignment in relationship to each other and your hinges WILL bind. Check this before skinning by marking out the cut lines for rudders and ailerons on the bare foam cores (on the upper side of the wings and outboard side of the winglets). Then lay a long straightedge on top of these lines where the hinges will eventually be to check the trueness of the cores. Fix any abnormalities before you skin the wings or winglets. Don't be lead into thinking that you can fix this problem later with a little micro later during the finishing stage. Micro goes on top of the wing or winglet surface while the hinges mount to the underside of the wing or winglet skin, (after the aft rib is installed in the aileron/rudder cutout area). So no amount of micro is gonna fix this problem. Several years ago there were numerous reports of abnormal wear in aileron hinges, and most of us who have the problem are now using teflon hinge pin sleeves to eliminate the abnormal wear. I'm convinced that the high hinge wear is due, at least in part, to misaligned and binding hinges. Stet Elliott flyez@earthlink.net (Albuquerque) flyez@rmi.net (Pueblo) Long-EZ N321EF Date: Sun, 11 Jul 1999 02:13:44 -0600 From: "Capital Steel Inc." Subject: COZY: Hot wiring cores. >From models I built I learned that cutting with a wire that is to hot leaves the excess ridges and divots. Furthermore the foam seems to be weakened about 1/8 to 3/16 deep and may fail under tension. In my case it was about 6 months after I finished one of my more spectacular paaint jobs. I have wondered if the failure on the canard Nat wrote about and blamed on //hard shelling// might also be this problem of cutting with too hot wires. From: "Nat Puffer" Subject: COZY: Incidence bolts Date: Thu, 15 Jul 1999 14:35:15 -0000 Builders, No one has mentioned this yet, but the spacing between the wing incidence bolts is critical. They prevent the wing from twisting. In Germany, the government was not satisfied that the spacing was sufficient, so they required a wing attachment at the leading edge of the strake. Of course, Burt didn't agree at all. But the point is that the spacing shown in the plans SHOULD NOT BE DECREASED! Nat From: "Nat Puffer" Subject: Re: COZY: Chapter 19-20 - wing tip detail Date: Wed, 25 Aug 1999 15:24:14 -0500 Brian, The area where the strobe and position lights attach obviously has to be flat, because the base of the light fixture is flat. The area of the wing tip forward of the light fixture is esthetic. Any shape (within reason) will do. Least drag would seem to dictate rounding. It is up to individual taste. Regards, Nat ---------- > From: Brian & Susan DeFord > To: Cozy Mailing List > Subject: COZY: Chapter 19-20 - wing tip detail > Date: Wednesday, August 25, 1999 4:29 PM > > The plans aren't real specific about how the tips of the wing are to be > finished. The area of interest to me is the 4-5 inches in front of the > winglet. I've seen some planes with the end of the wing tip flat and the > only detail I seem to find in the plans is a picture of how the strobe and > position lights are to be installed. It shows a rounded tip in the diagram > as viewed from the top of the wing. I haven't got a clue if the tip is > rounded as viewed from the front of the wing. So, any words of wisdom would > certainly be comforting...what have others done and more importantly - what > should NOT be done if there is an effect on the flying qualities of the > wing/winglet? > > Thanks, > Brian DeFord > brian@deford.com > Date: Wed, 02 Jun 1999 01:23:53 +0200 From: Jean-Jacques CLAUS Subject: COZY: Alternate Drill wing process Hi friends, I'm in the process to drill the wing's attach points. I red all the archive and i can say that's an horrible work for me. I spent 3 sunday ( and 2 spotface ) to drill only 3 points. So i would like to buy the " real Mc Coy hole saw" ( cf: archive ) to drill the 3 next attach points. Can anyone give me a source for this tool ? Thank you, Jean-Jacques CLAUS France From: Fritzx2@aol.com Date: Tue, 31 Aug 1999 23:43:07 EDT Subject: Re: COZY: Alternate Drill wing process Jean-Jacques CLAUS asked > I'm in the process to drill the wing's attach points. > I red all the archive and i can say that's an horrible work for me. I > spent 3 sunday ( and 2 spotface ) to drill only 3 points. > > So i would like to buy the " real Mc Coy hole saw" ( cf: archive ) to > drill the 3 next attach points. > > Can anyone give me a source for this tool ? First, I believe that the "real Mc Coy" is not a brand name but American slang for the an item that is the correct one and not a fake one or one that looks like it will work only to find out that it does not work. Now, I could be wrong because I haven't seen the entire message from the archive. I just purchased a hole saw and have used it to cut the solid glass tabs on the landing gear and on the landing gear bulkheads. It worked real well. The brand that I purchased is made in the USA by Starrett. The type of hole saw is called a Bi-Metal which means you can cut many different materials with the hole saw. If the original archive message did not mention it, you will have to bend or file the teeth on the hole saw slightly to get a nice fit with whatever you are going to put into the hole that you cut. This is easy. All I did was cut a practice hole out of a 1/4" thick scrap of solid fiberglass, measure or place whatever bushing or bolt into the hole to check the fit, and then tap on the teeth of the hole saw to, in my case, make the saw diameter slightly smaller. Repeat until you have a good fit. The hole saw teeth are probably brittle so you have to make adjustments slowly otherwise you will break a tooth on the saw if you try to bend it back the other way. You can buy Starrett tools on the Web at a company called MSC Industrial Supply Company by going to www.mscdirect.com. I bought my Starrett hole saws at a local tool supply off the shelf. You will need to buy an arbor (that contains the pilot drill and a way to attach various size hole saws to your drill), and hole saws of the appropriate size. The Starrett part number for the arbor that I bought is KA4. The nice thing about the Starrett arbor was that you could remove the 1/4" pilot drill and replace it with either a 12" long drill or 1/4" rod by just loosening a set screw. It just depends on how long of a pilot hole you have to work with. On the landing gear, you need a long pilot. On the wing, maybe you could get by with a shorter pilot. This arbor will accommodate hole saws from 9/16" to 1 3/16". The part number for the 5/8" diameter hole saw is KVH0058 and the part number for the 3/4" was KVH0034. As a price comparison, locally I paid around 5.00 US dollars each for the arbor and the hole saws just a couple days ago. The Starrett holes saws listed in the 1997 catalog are KAVH series. I'm not sure if Starrett changed the part number since then or the ones listed in the catalog are different in some way from the ones I bought locally. You could send a message to MSC at "Technical@mscdirect.com" to ask them about the differences between the hole saws I bought and the ones they listed in their 1997 catalog. Grainger is another tool distributor that I believe is on the web. I looked at their catalog at work and didn't see the series of Starrett that I wanted. Hope this helps. John Fritz fritzx2@aol.com From: "John Slade" Subject: COZY: Chap 19 - wing templates and aileron size Date: Wed, 29 Sep 1999 10:08:24 -0400 Hi Builders, I'm just starting on my wings, and have a couple of questions... 1. Templates. I borrowed a set of aluminum templates from another builder. When I matched them against my plans I found that they were all proportionately and uniformly smaller. The largest one was around 1/4 off in length. At first I though he'd done a photocopy and inadvertantly reduced the size but no, he says the templates were compared to his plans and were dead on. So. Why the difference? He has first edition plans and I have second edition plans. Did the template sizes change between the editions? Perhaps all first edition Cozys have smaller wings than second edition Cozys. Was this deliberate, or an accident in the printing process? My question is this. Does 1/4 inch in the chord matter for an airfoil? I see people talking about which side of the line to cut, so I'd expect a 1/4 inch or more to be a fairly big deal. Should I go with the smaller sizes which may be closer to the intended airfoil shape? 2. Ailerons. I read in the archives that both Burt Rutan and Aerocad increased the length of the ailerons and I'm wondering if I should do the same. If so, how much change is good? It'll cost me nothing to do at this stage. Seems to me that it cant do any harm and it would get me additional roll capability at slow speeds. Have others done this? Is it advisable? Anyone flown both? Is this considered a "major modification"? Since I've committed to writing the FAQ for Chapter 19, I'd appreciate any new suggestions for better ways to do things in this chapter. Regards, and thanks for all the email support regarding my attempt to get things moving in this maillist. I had nothing else to do while waiting for my wing foam to come in. It should be here today, so I'll probably shut up now! Regards, John Slade Cozy? #757 http://kgarden.com/cozy From: cdenk@ix.netcom.com Date: Wed, 29 Sep 1999 16:41:48 -0500 (CDT) Subject: Re: COZY: Chap 19 - wing templates and aileron size Was this deliberate, or >an accident in the printing process? My guess is the relative humidity was much lower when the templates were made. Possibly a combination of several stages of the reproduction process with high and low humiditys. Paper can easily in 24" go an 1/8" My question is this. Does 1/4 inch in the chord matter for an airfoil? A 1% change, can't get excited. Migh be able to check by using the wing plan view dimensions. > >2. Ailerons. Is this considered a "major modification"? Yes, if done after airworthiness certificate issued requires a new one and probably new test time. If done before certificate, its automatically there. From: "John Slade" Subject: COZY: Caution: Check Aileron Clearance Date: Sat, 2 Oct 1999 15:49:13 -0400 Builders, Anyone who didn't see the front page of Oct '99 Central States newsletter might be well advised to get a copy.... The story is of an EZ driver who had his ailerons LOCK UP in full deflection while in a high speed maneuver. Apparantly increased stick pressure with both hands had no effect. This pilot was bright enough to figure out that pulling G might free up his ailerons. He also had the "stones" to climb back to altitude and reproduce the problem! On landing he found marks on the paint of the outboard aileron balance weight and believes that the wing flexed enough for the hinge to move downward thus allowing the aileron to catch under the bottom wing skin. There's a diagram showing the problem. I checked my Cozy plans and, sure enough, the same diagram [without the annotations] is there showing the exact same recommended clearances of 0.08 to 0.20 inches. According to Central States, the suggested steps are: 1. Check your clearance all the way along with a 1/8 drill bit. 2. Consider beefing up the upper skin right by the hinge to reduce flex As an aside, the newsletter is full from cover to cover of interesting stuff. I read all 33 pages without putting it down. Regards, John Slade http://kgarden.com/cozy Date: Fri, 01 Oct 1999 06:49:29 -0400 From: "Marc J. Zeitlin" Subject: COZY: Chap 19 - wing templates and aileron size The now infamous John Slade writes: >....... Does 1/4 inch in >the chord matter for an airfoil? I see people talking about which side of >the line to cut, so I'd expect a 1/4 inch or more to be a fairly big deal. >Should I go with the smaller sizes which may be closer to the intended >airfoil shape? While Carl D. may think that the 1/4" is not critical (and to tell you the truth, at the less than 1% difference in wing area that it creates he's most probably right) I still don't think that I would ignore it. I think (says the guy who's wings are already built and actually has no reason to believe that they're any more accurate wrt chord size than anyone else's) that you should try to find a set of plans that haven't stretched and compare yours to theirs. Just getting a set of measurements of chord length from a few different people ought to give you an idea as to which ones are correct. You should then be able to create templates that are "right" (or closer to it). FWIW, going with what you've got certainly isn't dangerous - in that I'll agree with Carl 100%. >2. Ailerons. >I read in the archives that both Burt Rutan and Aerocad increased the length >of the ailerons and I'm wondering if I should do the same. If so, how much >change is good? It'll cost me nothing to do at this stage. Seems to me that >it cant do any harm and it would get me additional roll capability at slow >speeds. Have others done this? Is it advisable? Anyone flown both? Is this >considered a "major modification"? Well, I got the AeroCad cores, and the ailerons are 6" longer on the outside than the stock ailerons. More is better, right? :-). I believe the Berkut also has longer ailerons. I've flown in L.E.'s with short ailerons and in the AeroCad with longer ones - personally I couldn't tell the difference, but I'm not that experienced. Maybe at low speeds there's a noticable change. I figured I can always push the stick less, but I can't always push it more. Is this a "major mod"? My opinion would be no. It's substantially less modification than many other things that have been done - L.E.'s with long ailerons are still called L.E.'s. One thing to keep in mind, especially if doing the internal rudder belhorns, is that the cable conduit JUST BARELY misses the aileron corner on the longer ailerons. -- Marc J. Zeitlin mailto:marcz@ultranet.com http://www.ultranet.com/~marcz/ From: cdenk@ix.netcom.com Date: Sat, 2 Oct 1999 10:42:13 -0500 (CDT) Subject: Re: COZY: Chap 19 - wing templates and aileron size Was said Subject: Re: COZY: Chap 19 - wing templates and aileron size Date: Sun, 3 Oct 1999 01:59:08 -0400 All airfoils can be (and usually are) defined by a set of plotting coordinates. We could settle this whole issue of printing / copying / stretching / shrinking / etc. if we had access to those numbers so that we could loft our own (or at least compare the major dimensions against the templates to verify accuracy). How about it Nat, can we get those numbers? Russ Fisher Date: Sun, 03 Oct 1999 10:56:51 -0400 From: Jim Sower Subject: Re: COZY: Chap 19 - wing templates and aileron size I agree. It has been established (to my satisfaction at least) that the paper stretches and shrinks from common environmental factors (temperature, humidity, age?). At the very least, we need to know the actual length of, say, the waterline of each and every airfoil template. I don't know how easy it might be to *make* the drawing stretch or shrink back to a (more) proper size. But I think plotting coordinates would be a much better way to go. Dimensions to discover and quantify the problem, coordinates to correct a problem that's too big to fix with a hair drier. Just a theory, Jim S. Russ Fisher wrote: > All airfoils can be (and usually are) defined by a set of plotting > coordinates. We could settle this whole issue of printing / copying / > stretching / shrinking / etc. if we had access to those numbers so that we > could loft our own (or at least compare the major dimensions against the > templates to verify accuracy). How about it Nat, can we get those numbers? > > Russ Fisher Date: Sun, 03 Oct 1999 08:55:55 -0700 From: Eric Westland Subject: Re: COZY: Chap 19 - wing templates and aileron size For what they are worth, here's some thoughts from a fellow that is not an engineer and files his understanding of flying machines under the heading of "Miracles". I've belonged to this list from the very beginning, read the CSA newsletters and Canard Pushers. When ideas like plotting airfoil coordinates to make templates, spline sanding wing cores and leveling with lasers come to light, I always marveled at peoples ingenuity and determination to get their flying surfaces perfect or improve on the low-tech plans approach. Unfortunately, I would discover these techniques after completing a part and then worry that maybe my plane would end up cork-screwing through the air. As it turns out, it flies perfectly straight. So, while I encourage everyone to take whatever steps they feel are necessary to insure a safe, well flying plane, I can tell you from my own experience that great wings can be built by just using the large drawings and following the plans. Eric Westland Mukilteo, WA From: cdenk@ix.netcom.com Date: Sun, 3 Oct 1999 11:42:59 -0500 (CDT) Subject: Re: COZY: Chap 19 - wing templates and aileron size Was said I concur. More important to pay attention to alignment, straightness, etc., using simple inexpensive tools. Make sure your table is flat and level. Date: Mon, 04 Oct 1999 11:28:08 -0400 From: Blake Mantel Subject: Re: COZY: Chap 19 - wing templates and aileron size Russ Fisher wrote: > All airfoils can be (and usually are) defined by a set of plotting > coordinates. We could settle this whole issue of printing / copying / > stretching / shrinking / etc. if we had access to those numbers so that we > could loft our own (or at least compare the major dimensions against the > templates to verify accuracy). How about it Nat, can we get those numbers? > Russ Fisher I'd have to second that idea! When drawn up it could be wire EDM'ed or CNC milled out of whatever material you wanted to make a near "perfect" template. I just got through with plotting the FX63-137 (very low air speed, laminar flow) airfoil for the school's helicopter. And we determined that we needed a 28" cord length: so took the plotted points, scaled them to size, curve fitted them, then imported to Mastercam for a milling program for the rib sections. All the time that took was, oh, about an hour and a half. Even with typing in all the data points and checking it three times for errors. Later, Blake MkIV Plans #0008 -- CUM CATAPULTAE PROSCRIPTAE ERUNT TUM SOLI PROSCRIPTI CATAPULTAS HABEBUNT. (When catapults are outlawed, only outlaws will have catapults....) Triumph Tiger Motorcycle page at: http://www.tiac.net/users/blakem/ My Email address is altered due to the prevalence of bulk Email senders. To send me mail remove the two *'s before the TIAC.NET. From: Epplin John A Subject: COZY: Chapt 19, Wing templates Date: Sun, 3 Oct 1999 14:44:20 -0500 I notice that on chapter 19 page 10 there are dimensions for the chord, percent thickness and washout angle for the templates. I went through quite a bit of measuring and processing and came up with a set of .dxf drawings for the templates. Check the archives about 2.5 to 3 years ago. I obtained the Eppler 1230 coordinates from the University of IL airfoil site. Asked Nat if he knew what the modifications were, he said he did not personally know, someone had done this for Burt some years ago. I took the paper templates and using a layout table to sort of digitized all 4 templates. I then scaled and rotated the Eppler numbers to match and plotted these. It appeared that the changes were on the aft top of the airfoil, behind the spar. I don't recall all the details at the moment. I sort of merged these together to make a normalized airfoil which I used to scale and rotate for the inner 3 templates. The tip template is considerably different. I used the measured points for this one. I have the .dxf files and I believe the ordered pairs I used to gen the .dxf around somewhere. I calculated the capstrip cutout dimensions based on the layers of capstrip and sheerweb material at each station. This worked out very well, the fit was near perfect when the lay-up was completed. If anyone is interested I will see if I can get these together and send them a copy. Disclaimer: There are a pair of wings built to these templates, they have not yet flown. They do look good though. John Epplin Mk4 #467, sanding, sanding,,,filling, sanding.......... From: "John Slade" Subject: COZY: Chap 19 - tie downs Date: Wed, 27 Oct 1999 08:51:36 -0400 Thanks for all the answers to my tie down question. Seems that my idea wasn't so good after all. After a strong gust I'd probably be left with a rope, a padlock latch and a wing skin. The plane would be long gone. Consensus seems to be to drill the wing about 2 feet from the end and use an eye bolt or rope. Bruce Layne sent me a real neat suggestion about using rock climbing rope and neoprene washers, and I really like the Robin Du Bois system shown at http://cozy.canard.com/cad_files/ Now - what about the nose tiedown? Regards, John Slade Anyone need a couple of padlock latches? Date: Tue, 26 Oct 1999 20:07:27 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: Tie down width Hi John and All, > John Slade wrote: > Can anyone tell me the width of a standard tie down? - i.e. how many feet between the main tie down points for your average spam can. I put a tie down out in front of my hangars. I went over to transient parking to measure what was installed, figuring the airport should know the span - right? To my surprise, no 2 sets of tie downs were the same - some where way off compared to the majority. So I took a WAG. Probably within 2 feet of each tip sail. > I want to add a tie down point to my wing bottom skin before it cures. > I'm planning to attach a latch plate to the bottom skin with a small BID > layup somewhere along the spar cap. The latch plate is the type used to add > a padlock to a shed. It has a loop of metal welded to a 1 by 2 inch plate. > Any reason why this wouldn't work? It's not good enough. > I'm not expecting it to hold in a hurricane. Soooo, then what would be the point of installing one at all if it can't handle a sudden strong wind? If it's just glassed to the bottom skin and not part of the wing spar/shear web, and the wind happens to come up, it will rip the bottom wing skin open. Make it strong enough to handle a really strong wind, or your plane will be damaged. Also, if a pretty good attempt is not made to make a solid design, your insurance my be void for not trying. Also, insurance studies have proven more damage occurs to a plane when the chain or rope is not tight, than to those planes properly tied down, even in mild winds, for the plane tries to lift off in place. One of the ways we did it was to glass a fiberglass tube (I think it was arrow stock) to the front of the wing spar/shear web at the distance from the tip sail we wanted from top to bottom wing skins. Then we use a large eye bolt with 2" diameter padded washers we made, one on the bottom skin against the eye bolt and wing skin (padded side to skin of course), the other on the top skin next to the wing nut. Both of these items are stored in the nose of the plane when not in use (less drag) in the tool bag that is always kept in the plane. Could help out a little if you need a some useful ballast to have available to move fore and aft too. Also, I've seen straps that are just wrapped around the wing connected to a rope. They threw the strap loop over the tip sail to get it wrapped around (over and under) the wing. Draw back: the strap may crush the trailing edge of the wing in a strong wind. Another idea: many years ago someone came up with a very clever tie down similar to the spring loaded to recess eye used on the Cessna Cardinal RG, except it was a little long on one side of the pivot so the heavier weight on one side would make it close when not in use. It was mounted and pivoted off the front of the wing spar/shear web. A minor problem with it is that it came out while pulling g's. A spring would keep it tucked away (like the spring force use for the Cardinal RG tie down). I think the installation instructions and drawings where in a CSA newsletter long ago. Any one remember the issue, or where the idea is really published? Infinity's Forever, JD Date: Wed, 27 Oct 1999 17:43:58 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: Tie down width Hi John, > > John Slade wrote: > > I want to add a tie down point to my wing bottom skin before it cures. > > Marc Zeitlin wrote: > There's a very elegant and simple hidden tie down shown at: > > http://cozy.canard.com/cad_files/ > > It has all the structural and aesthetic characteristics one could want, and > it's cheap. Yeap, that's it - the Cardinal RG idea I mentioned. Date: Thu, 28 Oct 1999 19:47:36 -0600 From: Dave Chapman Subject: COZY: Re: Tie down width (now retractable tiedown) On the subject of tiedowns, the best system I have ever heard of is as follows: Cut a piece of aluminum plate (.125 or so) to approximately 4" x 1.5" Drill a hole slightly off center that is just larger than the washers on the lower wing attach bolt. Drill another hole centered on the short end of the plate Round the edges and install onto the lower wing attach bolt. Now open up the area at the outboard bottom side of the area where the plate is installed. (this allows the plate to be rotated down so you can tie the plane down with the other hole) I'll try to do a little ascii art.... top ________________________________ | | inbd | ( ) ( ) | outboard | | ----------------________________ Note where the plate is relieved on the inbd bottom side so that when not in use it rests retracted (that end is heavier). In use the plate is rotated down (about the center hole/bottom wing attach bolt) and the tiedown is attached. Note that the plate is not bolted by the wing attach bolt but only is loosely around the bolt and washers. The only modifications required to the plane is to trim some of the glass that is closing the gap between the wing and the strake on the bottom outboard of the wing attach bolt. Sure beats drilling holes in wings or putting straps on the wings! Regards Dave Dave Chapman (Pilot@xmission.com) "This is USHGA #5742 a spiritual calling to Park City, Utah set one's soul free by flight...." http://www.xmission.com/~pilot Cozy 3 on gear, with the engine on, in other words, 80% done and 80% to go.. **************************************************************************** The box said 'Requires Windows 98, or better.' So I bought a Macintosh. **************************************************************************** Date: Wed, 27 Oct 1999 10:12:59 -0500 From: Michael Pollock Subject: COZY: RE: Tie Downs John Slade wrote: >I want to add a tie down point to my wing bottom skin before it cures. On our Velocity, we attached the tie down points to the ends of the center-section spar using bolts through the spar cap ends. The center-section spar for the Velocity and the Cozy MKIV are very close in length. This is per the Velocity instructions and we have not had any problems with our airplane flying while we were not there:) I would not cut any holes through the SPAR CAP for tie-down attachments. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 From: "John Slade" Subject: COZY: Tie down width Date: Tue, 26 Oct 1999 21:00:36 -0400 Builders, I want to add a tie down point to my wing bottom skin before it cures. Can anyone tell me the width of a standard tie down? - i.e. how many feet between the main tie down points for your average spam can. I'm planning to attach a latch plate to the bottom skin with a small BID layup somewhere along the spar cap. The latch plate is the type used to add a padlock to a shed. It has a loop of metal welded to a 1 by 2 inch plate. Any reason why this wouldn't work? I'm not expecting it to hold in a hurricane. Regards, John Slade Cozy #757 http://kgarden.com/cozy From: sdbish@juno.com Subject: COZY: Tie down width Date: Tue, 26 Oct 1999 23:38:28 EDT "John Slade" wrote: I want to add a tie down point to my wing bottom skin before it cures. I'm planning to attach a latch plate to the bottom skin with a small BID layup somewhere along the spar cap. The latch plate is the type used to add a padlock to a shed. It has a loop of metal welded to a 1 by 2 inch plate. Regards, John Slade Force from the tie down on this tends to pull the glass directly away from the foam. I see this as being the weakest bonding strength. Suggest a hole through the spar cap, which a bolt or pin can be inserted through, with a large washer on top of the wing. This way you have the full height of the spar cap for strength, not just the peal strength of the glass. Marv Bishop ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: http://dl.www.juno.com/dynoget/tagj. From: MARC_ZEITLIN@HP-Andover-om1.om.hp.com Date: Wed, 27 Oct 1999 07:51:07 -0400 Subject: COZY: Tie down width > "John Slade" wrote: > I want to add a tie down point to my wing bottom skin before it cures. Marv Bishop wrote; > Suggest a hole through the spar cap...... There's a very elegant and simple hidden tie down shown at: http://cozy.canard.com/cad_files/ It has all the structural and aesthetic characteristics one could want, and it's cheap. -- Marc J. Zeitlin marcz@ultranet.com http://cozy.canard.com Non Impediti Ratione Cognitanis (C&C) Date: Wed, 27 Oct 1999 08:19:08 -0500 From: Michael Pollock Subject: RE: COZY: Tie down width On our Velocity, we attached the tie down points to the ends of the center-section spar using bolts through the spar cap ends. The center-section spar for the Velocity and the Cozy MKIV are very close in length. This is per the Velocity instructions and we have not had any problems with our airplane flying while we were not there:) John Slade wrote: >I want to add a tie down point to my wing bottom skin before it cures. On our Velocity, we attached the tie down points to the ends of the center-section spar using bolts through the spar cap ends. The center-section spar for the Velocity and the Cozy MKIV are very close in length. This is per the Velocity instructions and we have not had any problems with our airplane flying while we were not there:) I would not cut any holes through the SPAR CAP for tie-down attachments. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 -----Original Message----- From: owner-cozy_builders@betaweb.com [mailto:owner-cozy_builders@betaweb.com]On Behalf Of John Slade Sent: Tuesday, October 26, 1999 8:01 PM To: Cozy builders; canard-aviators@canard.com Subject: COZY: Tie down width Builders, I want to add a tie down point to my wing bottom skin before it cures. Can anyone tell me the width of a standard tie down? - i.e. how many feet between the main tie down points for your average spam can. I'm planning to attach a latch plate to the bottom skin with a small BID layup somewhere along the spar cap. The latch plate is the type used to add a padlock to a shed. It has a loop of metal welded to a 1 by 2 inch plate. Any reason why this wouldn't work? I'm not expecting it to hold in a hurricane. Regards, John Slade Cozy #757 http://kgarden.com/cozy From: "astrong" Subject: Re: COZY: Tie down width Date: Wed, 27 Oct 1999 12:21:45 -0700 -----Original Message----- From: John Slade To: Cozy builders ; canard-aviators@canard.com Date: Tuesday, October 26, 1999 6:27 PM Subject: COZY: Tie down width >"Builders, >I want to add a tie down point to my wing bottom skin before it cures. > >Can anyone tell me the width of a standard tie down? - i.e. how many feet >between the main tie down points for your average spam can." My tiedown is located 12" from the inside of the lower winglet, with 6` of 1/2" poly rope I can always reach the ground attachment. My tiedown is bolted to the wing sparcap with only a 1/4" hole showing through the lower skin and attaches with a quick release pin. Alex From: cdenk@ix.netcom.com Date: Wed, 27 Oct 1999 18:20:47 -0400 (EDT) Subject: Re: COZY: Tie down width My tiedowns are standard Cosy drawing, a 1/4" I.D. tubing through the wing about 12" inboard from the winglet. An "AN" eyebolt with wide area washer top and bottom cushioned with a washer of red silicone baffle material. A threaded type carabiner goes through the "eye" of the bolt and provides a larger hole for the nylon 1/2" rope to pass through. THe ropes are about 7' long and the majority of the tie downs can be reached, sometimes making a loop in a fixed loop. An "AN" wingnut and safety pin completes the setup. The nose which is an 2" square x 1/4" aluminum plate between the fuselage skins under the canard takes advantage of the structure in that area.A camloc 4002 series has a 1000 lb. load ability, which I feel is adequate for the nose. A piece of aluminum 1/8" angle is held by the camloc and has a hole in the other leg for the rope. I have a 8' rope for the nose, could be a couple of feet longer at times. Carry 2 extra 6' rope for use when necessary. Remember when tying the wings to tie the nose. It doesn't take much down force if the wind would move the plane forward to raise the nose and result setting on the tail. From: cdenk@ix.netcom.com Date: Wed, 27 Oct 1999 18:36:44 -0400 (EDT) Subject: Re: COZY: Tie down width Was said Caution, when the tiedown force (big storm is when needed), this is an new loading condition, and therfore an analysis and redesign is in order. The size location of the hole, and many details is required. The hole through the wing detail works well, and is not objectionable looks. I have the wife trained when we land for the night, she puts the eyebolts in while I secure other items and tie the ropes properly. From: "James A. White" Subject: COZY: EZ Wing Alignment Procedure Date: Wed, 24 Nov 1999 21:22:46 -0800 I found an EZ way to confirm if both wings are properly aligned with respect to one another. Install both wings. Level the fuselage in the fore and aft direction. Use a water level to compare the water line readings at the leading and trailing edges at B.L. 100. The water level of the leading edge should equal the trailing edge at B.L. 100. The left and right wings may have different waterline readings, but their respective trailing and leading edges should be the same. Someone should double-check my math and get back to this forum if B.L. 100 is the correct station or not. The actual station may be different but I believe the technique is sound. I trust this method more than I do the level boards that I bondoed to the top of my wings. Jim White N44QT (In honor of my cozy cutie wife.) From: cdenk@ix.netcom.com Date: Thu, 25 Nov 1999 08:53:03 -0500 (EST) Subject: Re: COZY: EZ Wing Alignment Procedure Was said I used templates made from hot wire templates at the foam joints, adjusted for fiberglass thickness to determine the leading edge waterline levels (elevation). Then used water level (vinyl tubing from local hardware store) to check leading and trailing edges at numerous locations. Granted you can't bend the wing, but the more measurements, and averaging the error, paying more attention the the outboard readings, the more accurate the setting will be. I was using mixing sticks for shims, and went around and around checking locations and adjusting shims for several evenings before building the strakes.