Date: Sun, 30 Apr 95 13:50:38 EDT Subject: Seatbelts >As to Cozy building, I am just finishing up the detail work of chapter 6 >before building the bottom and installing it, another couple of weeks of >work. By the way, a question for you. Is it necessary to purchase the >entire seat belt assy from Wicks in chap 8? That's a lot of money to sit >around for a couple of years unused. Well, that's a good question. I just started doing the seatbelt attach points, and to tell you the truth, I see no reason why you actually have to have the seatbelts to do it. Didn't think about it before getting them. Wish I had :-). Get the bolts, etc. though. Sounds like you're making good progress. You'll pass me in no-time; I'll be either on vacation or working outside most of the summer. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Fri, 16 Jun 1995 22:55:02 -0400 From: MKansky@aol.com Subject: Belt Attachments Marc, I recieved the templates today. They look great. I will be ordering the foam in the next couple of days. I appreciate you sending them out. I am finishing chapter 8 and have run into two problems. First, where can you purchase an509-416R18 for the step. wicks didn't have them and I don't think alexander has them either. Chapter 8 page 2 step 6 second question. I am finding the an525-416r16 too short. Are the holes for the seat belt bracket suppose to go through the both the birch support piece and the longerons? How deep did you sink the bolt? I went through the foam to the longeron and stopped there. If I am on the wrong track I don't want to go any further. ...Marty (an overly cautious builder) Date: Fri, 16 Jun 1995 23:02:27 -0400 From: MKansky@aol.com Subject: rear air duct Marc, On page 8-3 fig 16 it shows the air duct. Should the top of the baffle be flush with the top of forward landing gear bulkhead? Mine extents over 1/4 " above it? I never see many questions like this in emails. Am I the only one having trouble understanding the plans? ...Marty Date: Sun, 18 Jun 95 11:52:45 EDT Subject: chapter 8 questions Marty K. writes: >On page 8-3 fig 16 it shows the air duct. Should the top of the baffle be >flush with the top of forward landing gear bulkhead? Mine extents over 1/4 >" above it? Well, my interpretation was that it should be flush. After I made the rear air duct assembly, I sanded the bottom, the top, and the baffle to get everything even. This is not exactly a critical assembly, dimensionally :-). >I never see many questions like this in emails. Am I the only one having >trouble understanding the plans? Well, I find myself re-reading the plans three or four times to figure things out as well - we should consider ourselves lucky - I saw the KR-2 plans about 12 years ago (maybe they've gotten better) and they essentially said: Build the fuselage. Done yet? good. Now build the wing. Done yet? good. Now put the engine on. Go fly! I'd say don't worry about asking questions - that's the point of the mailing list. If people either don't know the answer, or don't care, they'll ignore it, but the two or three people who know what you're talking about will answer you, and then you'll have four opinions to sort out :-). >I am finishing chapter 8 and have run into two problems. First, where can >you purchase an509-416R18 for the step. wicks didn't have them and I don't >think alexander has them either. I needed to use MS24694-S111 for the step mount (remember not to really mount the step in chapter 8 - Nat recommended holding off so that it doesn't get in the way, until some indeterminate later time). Wicks had those. I think the screws you need for some of these are highly dependent upon your shaping techniques - 1/8" differences could be very easy to get, depending. >Chapter 8 page 2 step 6 >second question. I am finding the an525-416r16 too short. Are the holes for >the seat belt bracket suppose to go through the both the birch support piece >and the longerons? How deep did you sink the bolt? I went through the foam >to the longeron and stopped there. If I am on the wrong track I don't want >to go any further. Well, the longeron is supposed to be right under the glass layers on the outside of the fuselage - there shouldn't be any foam over it. Be that as it may, I counter-bored the holes for the screws into the longerons far enough to bury the head - I THOUGHT that was what NAT said to do in the plans. Once I had done that, the screws were long enough. Some of the c'bores had to be a bit deeper, but none of them went even half way through the longeron. It sounds as if you can go a reasonable abmount deeper into the longeron with a c'bore. The hole gets filled with flox, anyway. Anyone else have any comments on these issues to reassure Marty (and me)? -- Marc J. Zeitlin E-Mail: marcz@an.hp.com From: Marc J. Zeitlin Subject: chap_08 screws Date: Sun, 18 Jun 95 12:10:04 EDT People; I lied. After looking back over my record, I found that I had ordered four AN525-416R20 screws for the seatbelt attach points, because I couldn't get the R18's. I just went a little shallower on the c'bores into the longerons. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Sun, 18 Jun 95 12:10:04 EDT Subject: chap_08 screws People; I lied. After looking back over my record, I found that I had ordered four AN525-416R20 screws for the seatbelt attach points, because I couldn't get the R18's. I just went a little shallower on the c'bores into the longerons. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Sun, 18 Jun 1995 18:41:05 -0400 From: MKansky@aol.com Subject: Re: chap_08 screws Marc, Thanks for the advice. I have only drilled one seatbelt hole through the fuselage. I think that the angle for which I drilled it didn't go through the center, thus me having to go through foam. I am glad to see you ordered the longer bolts. I will be doing the same this week along with the foam for the canard. sorry to hear about your canard. I have several panic attacks myself throughout the project to find they weren't as serious as I thought. ...Marty Date: Sun, 9 Jul 1995 20:33:25 -0400 From: Marcnadine@aol.com Subject: Extra Parts on Ch. 8 I completed Ch. 8 last week and found that I had a lot of extra bolts, washers, etc. left over. After reviewing the all 3 pages, I found no reference to the parts that were called out for in the materials list for this chapter. Did anyone else have the same problem? Marc P. From: Marc J. Zeitlin Subject: Extra Parts on Ch. 8 (fwd) Date: Sun, 9 Jul 95 23:02:38 EDT Marc P. writes: >I completed Ch. 8 last week and found that I had a lot of extra bolts, >washers, etc. left over. After reviewing the all 3 pages, I found no >reference to the parts that were called out for in the materials list for >this chapter. >Did anyone else have the same problem? The plans give you the chance (which I did NOT take) to install the canopy hinge before glassing the shoulder support in place. I believe (as I have a bunch of hardware too) that this stuff was for that. I'm holding it aside for the canopy chapter. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Tue, 11 Jul 1995 08:55:14 -0400 From: NBalog@aol.com Subject: Seatbelts/shoulder harness spacing Here's a long one, folks, bear with me: 11 July 1995: I've got a lot of respect for Nat, really, I do; I also have a lot of respect for the TUEV (ascii doesn't do umlauts, that's Technische Ueberpruefungs Verein, sort of the German equivalent of America's Underwriter's Laboratory or Consumer Reports), and the socially responsible euro- pean concept of product and consumer safety, but come on, 22cm (8.66 inches) of space between mounting tabs for the shoulder harnesses, as opposed to 11.5 inches? I'm not an expert, nor am I an FAA or NTSB accident investigator, but I have looked at a lot of NTSB reports, and a lot of the files on the FAA safety bulletin board, and nowhere have I seen information on shoulder harnesses and pilots slipping through them in accidents, but maybe this is just selective memory effect, or the sort of thing that happens when you buy a certain brand of car and all of a sudden you notice there are a LOT of them out there that you hadn't noticed before; they were always there but you just didn't notice. Now that it's been brought to my attention, become part of my consciousness, the same, as regards safety belt and shoulder harness effectiveness in general aviation accidents, is, I think, a non-event. I mean, I don't think it's happening. For at least two reasons: First, most GA accident "victims" (since the majority of GA accidents are due to pilot error, there are no victims, are there?) die due to one of two things, overwhelming multiple trauma (blunt, laceration, puncture) as it is not unusual to sustain in excess of 20g on impact; this, and a com- bination of fire and/or asphyxiation/smoke inhalation, I believe (feel free to correct me on this, I'm not quoting gospel, just pontificating), make the question of retention by seatbelts absurd. No where have I read that people have slipped out of the harness except in cases of, say, flying out of IFR in IMC into VMC into a mountain face in excess of two or three hundred knots in which case what slips out of the harness goes *SPLAT* on the instrument panel as organic jelly in which case harness width is moot. Slippage at lower airspeeds just doesn't show up anywhere. Second, in twenty plus years of homebuilder construction of the Rutan composites, literally thousands of planes in this model alone, plus quickies, RV's, now pulsars, cozies, velocities, coyotes, ad nauseum, not to mention the GA aircraft from Piper, Cessna, Mooney, Beech, having crashed and burned, or just crashed, the pilots/passengers sustaining varying degrees of trauma and/or death (unintentional attempt at humor here) where is the hard evidence that a change is necessary to improve accident survivability other than from deep within the recesses of some laboratory in Europa? I know Nat's training as an engineer (similar to my training as a physician) should have imbued him with a healthy sense of skepticism; can he share this source of information, the incontrovertible evidence, with us, and/or get it published in general aviation journals as Flying, AOPA or EAA magazines or tell us where to find it on line? Third: to take off from that last sentence in the second issue, why hasn't this shown up in the GA press? Is it this new an idea? Don't the GA manufacturers use crash-test dummies? Or do they just wait for the test-pilot dummy results? Hey, all you starving personal injury lawyers (a pleasant image that) , fresh meat! Gross oversights in safety in the manufacture of GA aircraft has caused the unnecessary death, dismemberment and disability of hundreds of pilots by a margin of 2.84 inches in shoulder harness mounting points and untold bezillions of dollars worth of grief (pain and suffering) to the family and spouses of the dearly and nearly departed. Sue now, beat the rush, beat the manufacturers to court as they file for chapter eleven proceedings. Fourth and last (I gotta do some work sometime today): this is going to cause a lot of people more than a modicum of heartache/headache and just plain hassle as they have to sand and cut and trim and glue and patch and paint and drill to put in the new inserts, aluminum tabs, cut up the headrests, etc., six hours work at least (estimate only) not a big deal if there's a significant safety issue here. But is there? I could go on (some of you have already thought I was), but I'd like some feedback, and to let you know how I went about installing my belts. 22cm as the outside dimension center to center, 8.66" seemed absurdly narrow (and the belts chafed my neck) and it was too difficult to work with hundredths of an inch gradations, so I rounded up to 9.0 inches; we're talking millimeters difference here, 8.6mm to be exact, or 0.34 inch (2.54 cm = 1 in). So the difference between 9 and 11.5" (the original on-center dimension) is 2.5 inches; splitting the difference gives +/- 1.25 inches to give measurements of 5.25 inches to the center of the first birch plywood insert (4 plus 1.25) and 10.25 (11.5 minus 1.25) to the next; this still makes for 15.25 from the edge of the foam to the center of the inside insert (a redundancy check, measure twice, cut once). I did this setup last night, and I think I'm going to live with it; I'll let you know if I slip out someday; you do likewise, also let me know if you hear of anyone else becoming unrestrained. By the way, where in the parts list is the material for the aluminum strips (for the headrest retaining plate); I admit I haven't read through the parts list (yet again) but I did go through my box of chapter eight parts without coming up with the Al plate, and does anyone see any reason NOT to mount these tabs in the headrest beFORE glassing and mounting, thereby saving some cutting, trimming filling, and a two-inch tape layup later on or is this 2-in layup even necessary? I'll have to look at the plans again, but I thought these tapes were only over the Al plates, not side to side (although this makes more sense). Thanks, looking forward to the firestorm of replies. Too bad Nat's not online to reply (or are you?). -Norm Date: Tue, 11 Jul 1995 09:10:25 -0400 From: NBalog@aol.com Subject: Re: Extra Parts on Ch. 8 (fwd) Anyone else have this problem? I'm just starting on chpt 8 and am looking ahead into chapter 18 (!) to see how to mount the canopy and make the provision for the removable top; seems to me that you can do the BID layup on the hinge mounting pieces between F-28 and the instrument panel at the same time as the layup for the UND side reinforcements, saving some sanding and other hassle later on. From: Marc J. Zeitlin Subject: Seatbelts/shoulder harness spacing (fwd) Date: Tue, 11 Jul 95 9:26:55 EDT Norm B. writes: >Here's a long one, folks, bear with me: . . Norm's long harangue on seatbelt attach point spacing omitted :-). . . >I could go on (some of you have already thought I was), but I'd like some >feedback, and to let you >know how I went about installing my belts. . Omit lots of complex math here. . >...................... I did this setup last night, >and I think I'm going to live with it; I'll let you know if I slip out >someday; you do likewise, also let me know if you hear of anyone else >becoming unrestrained. I was also surprised to read that this should be a mandatory change. I'm 5' 7" and 150 lb., and my shoulders are about 13" wide. I think the seatbelts would chafe my neck as well at 8.66". I had already installed the hard points, and without evidence (as Norm stated) to the contrary, I'm going to leave them where they are, at 11.5". >By the way, where in the parts list is the material for the aluminum strips >(for the headrest retaining >plate); I admit I haven't read through the parts list (yet again) but I did >go through my box of chapter eight parts without coming up with the Al plate, >and does anyone see any reason NOT to mount these tabs in the headrest beFORE >glassing and mounting, thereby saving some cutting, trimming filling, and a >two-inch tape layup later on or is this 2-in layup even necessary? I'll have >to look at the plans again, but I thought these tapes were only over the Al >plates, not side to side (although this makes more sense). I thought there was some 1/16" aluminum left over from some other chapter for this purpose, but maybe I just "borrowed" a piece from the shop at work. The 2" layup is stated as optional in the plans - I blew it off. As far as mounting the tabs before glassing - how would you know where to drill the holes and make sure they lined up? You need to lay up the pads and top surface (of the SHOULDER SUPPORT, not the headrest :-) ), drill the holes, and then locate the nutplate and tab. Unless you're extremely accurate, the hole wouldn't line up with the nutplate. >Thanks, looking forward to the firestorm of replies. > >Too bad Nat's not online to reply (or are you?). Not yet :-). -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Tue, 11 Jul 1995 09:59:23 -0400 From: SidLloyd@aol.com Subject: Re: Seatbelts/shoulder harness spacing (fwd) My concern with the shoulder seatbelt attach points is structural rather than spacing. I brought this up to Nat when I glassed in the attach points, and he said if I was concerned to add a few my plys. My concern is that there isn't much holding the shoulder support section onto the seat back. Take a look at the layup schedule. There isn't anything that laps around the outside of the acute angle formed by the top of the shoulder support and the seat back. And there isn't an internal layup either (impossible to do anyway). All you've got is flox and the top layup giving you two glass to glass attach points on top: the forward ply of the seat back and the rearward ply of the seat back. Did anyone else notice this? Anyone have any ideas how to strengthen this? Do we need to??? Sid From: Marc J. Zeitlin Subject: Re: Seatbelts/shoulder harness spacing (fwd) Date: Tue, 11 Jul 95 10:19:06 EDT Sid L. writes: >My concern with the shoulder seatbelt attach points is structural rather than >spacing. I brought this up to Nat when I glassed in the attach points, and >he said if I was concerned to add a few my plys. >................... All you've got is flox and the top layup giving >you two glass to glass attach points on top: the forward ply of the seat back >and the rearward ply of the seat back. > >Did anyone else notice this? Hadn't thought of this before - thanks for bringing it to my attention :-). >Anyone have any ideas how to strengthen this? Well, as you suggested, rounding the acute corner of the seatback and putting a couple of plies over it ...... >..................... Do we need to??? Let's assume that the rear flox line is 1/2" wide and 40" long (20 sq. in. total). Let's also assume an epoxy bond strength of 300 psi (I have no idea if this is correct, it could be anywhere from 100 psi to 3000 psi, for all I know, but I'd guess this is conservative). Let's also assume that NOTHING else is holding the shoulder harnesses to the seatback, and that the seatback won't break free before you're already dead. So, the shoulder support shouldn't break off until the load is ~6000 lb (20 sq. in. x 300 psi). With 2 200 lb people in the front seat, this is about 15 g's. Hmmm. Given the uncertainty and conservativism here, I don't know what to recommend. Anyone willing to do a destructive test with a 10 ton comalong, pulling on the shoulder supports until something gives? No, I thought not. Maybe Gordon B. can give us some insight regarding the actual strength of the epoxy bond. Maybe some of the other M.E./A.E. here can point out where I've screwed up. Maybe it's just worth rounding the corners and putting one or two 2" wide BID tapes around it, for insurance. Costs almost nothing, won't take an hour. Help? -- Marc J. Zeitlin E-Mail: marcz@an.hp.com ; Tue, 11 Jul 1995 11:13:57 -0400 Date: Tue, 11 Jul 95 09:48:52 CDT From: qtdalls!ken%qtdalls@uunet.uu.net (Ken Reiter) Subject: Re: Seatbelts/shoulder harness spacing (fwd) Hello to All, I have been thinking about this issue and I have an idea. What about adding a strap to connect the two straps coming from the attach points. The extra strap would tie the two straps together with the correct distance behind the persons neck. This would by-pass the modifications to the attach points. What do you guys think??? > From uunet!hpwarhw.an.hp.com!marcz Tue Jul 11 09:12:32 1995 > Return-Path: > From: "Marc J. Zeitlin" > Subject: Seatbelts/shoulder harness spacing (fwd) > To: uunet!hpwarhw.an.hp.com!cozy_builders (Cozy MK-IV Builders) > Date: Tue, 11 Jul 95 9:26:55 EDT > Mailer: Elm [revision: 70.85] > Content-Length: 58 > X-Lines: 3 > > Norm B. writes: > > >Here's a long one, folks, bear with me: > From: Marc J. Zeitlin Subject: Re: Seatbelts/shoulder harness spacing (fwd) Date: Tue, 11 Jul 95 11:35:15 EDT Ken R. writes: >What about adding a strap to connect the two straps coming from >the attach points. The extra strap would tie the two straps together >with the correct distance behind the persons neck. This would by-pass >the modifications to the attach points. > >What do you guys think??? Sound like a good idea to me. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Tue, 11 Jul 1995 12:26:08 -0400 From: CozyBldr@aol.com Subject: Seatbelt Safety Ken R. writes: >What about adding a strap to connect the two straps coming from >the attach points. The extra strap would tie the two straps together >with the correct distance behind the persons neck. This would by-pass >the modifications to the attach points. > > Another idea, as suggested by a coworker who is into auto racing, attach the extra strap in the front on the chest. That would certainly do the trick and it's been tested on the race circuit. That's how I intend to attack the problem. Paul S. Sender: From: "Michael Antares" Organization: Eldepro Date: Tue, 11 Jul 1995 08:30:29 -0800 Subject: Re: Seatbelts/shoulder harness spacing (fwd) Reply-To: mantares@crl.com I'm not a mechanical engineer (just electronic) but I know from experience that bonds are much, much stronger in tension than in shear. That would imply that the upper bond to the top of the seat would be much weaker than the lower one and would be improved greatly by carrying it over around the back of the seat. Any comments? This is perfect timing for me as I'm just starting chap 8! Michael Date: Thu, 13 Jul 1995 09:19:39 -0400 From: NBalog@aol.com Subject: headrests this keeps getting returned to my by the DAEMON Mailer at HP for some weird reason, if you've seen it already, please reply, give me a "radio check" ferchrissakes or I'll keep uploading this until someone does ------------------------------ Am I the only one with these questions? Starting on chapter eight, I got the parts for the headrests marked and glassed last night, and I'm looking at chapter eight, page one, and see that yes, clearly there is a left, and a right headrest, and I know the left headrest gets mounted on the canopy bulkhead, but if the vertical face of the headrest is forward, sloped side to the rear, what is the purpose of making the left headrest with a sloped rear surface if it gets mounted on a vertical canopy bulkhead. What's going on here? Anyone else (Eric?) this far into the building who can give me a clue? thanks in advance. -Norm From: Marc J. Zeitlin Subject: Seatbelt/harness attach points Date: Thu, 13 Jul 95 9:44:39 EDT Another forward from Nick P. (should be the last forward for anyone [at least until I screw up again :-) ] ); >Seatbelt / shoulder harness attach points. >========================================== > >The issue of 22cm (8.66 inches) of space between mounting tabs for the >shoulder harnesses, as opposed to 11.5 inches, we must consider that this >is not a single seater and that we will carry passengers of different body >size and width across the shoulders (we must also consider their safety). >The 8.66inch dimension is the one most applicable for the range from >children to adults. We may however wish to make different seat positions >with different dimensions based on who might sit there - it is however a >valid consideration that Nat has raised and is in the interest of passenger >safety - Thanks Nat. > >Seat belt attach fitting design is well described in the book Composite Basics >by Andrew Marshall, 720 Appaloosa Drive, Walnut Creek, CA 94596 - >advertised in Sport Aviation. > > > >Nick Parkyn........... Date: Thu, 13 Jul 1995 11:42:21 -0400 From: SidLloyd@aol.com Subject: Re: headrests In a message dated 95-07-13 09:41:36 EDT, marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) writes: >>Starting on chapter eight, I got the parts for the headrests marked and >>glassed last night, and I'm looking at chapter eight, page one, and see that >>yes, clearly there is a left, and a right headrest, and I know the left >>headrest gets mounted on the canopy bulkhead, but if the vertical face of >>the headrest is forward, sloped side to the rear, what is the purpose of >>making the left headrest with a sloped rear surface if it gets mounted on a >>vertical canopy bulkhead. What's going on here? >> >>Anyone else (Eric?) this far into the building who can give me a clue? >> >>thanks in advance. >> >>-Norm > > Yeah, I had the same question and asked Nat. If I remember correctly, he said just to make it fit. In other words, it's not correct in the plans. I will add glass to make it vertical. Sid Date: Thu, 13 Jul 1995 08:43:59 -0700 (PDT) From: Eric Westland Subject: Re: headrests On Thu, 13 Jul 1995, Marc J. Zeitlin wrote: > I'm forwarding this for Norm B., who asks: > > >Starting on chapter eight, I got the parts for the headrests marked and > >glassed last night, and I'm looking at chapter eight, page one, and see that > >yes, clearly there is a left, and a right headrest, and I know the left > >headrest gets mounted on the canopy bulkhead, but if the vertical face of > >the headrest is forward, sloped side to the rear, what is the purpose of > >making the left headrest with a sloped rear surface if it gets mounted on a > >vertical canopy bulkhead. What's going on here? > > > >Anyone else (Eric?) this far into the building who can give me a clue? > > > >thanks in advance. > > > >-Norm > > Marc Z. > I have not looked at the plans page to see what the difference may be between the left and right headrests, but I would suggest for now that you wait to build them and if they are built, wait to mount them as they will be in the way for a long time. In the meantime, you may see an improved way to provide roll over protection and rest your noggin. Eric Date: Thu, 13 Jul 1995 13:49:40 -0400 (EDT) From: Tech Support - Rick Subject: Re: Seatbelts/shoulder harness spacing (fwd) As far as this goes about the strength, ever seen the Long-Ez crash fuses'? They run the same layup schedule. The Cozy's that have crashed have never ripped out the shoulder rest or the seat belt hard points. mY .02 worth. Rick C. Date: Tue, 25 Jul 1995 10:01:36 -0400 From: NBalog@aol.com Subject: seatbelt 7-ply reinforcements Chapter eight... So it only took about an hour and a half last night to figure out that this alternating BID/UND reinforcement can't be done by transferring the completed 7-ply layup from waxed paper to the heat duct/fuselage cabin floor. Nice try, though, and for a while it really looked like it would work. Now I have this crumpled up 7 layer freeform fibreglass sculpture (I call it "Inferno, minus 2 levels") I'm donating to the museum of modern art for a BIG tax write-off. Otherwise, bummer. Question: how best to do this layup so as to: 1- get that "feathered edge" that Nat refers to 2- keep the weight (excess epoxy) down 3- get the air out without using spot vacuum bagging (becoming a better idea the longer I work on this); a one- or two- inch brush, hairdryer and roller (where it fits)? I dread doing those landing gear reinforcements in chapter nine. Thanks. -Norm From: Marc J. Zeitlin Subject: seatbelt 7-ply reinforcements (fwd) Date: Tue, 25 Jul 95 10:20:12 EDT Norm B. writes: >So it only took about an hour and a half last night to figure out that this >alternating BID/UND reinforcement can't be done by transferring the completed >7-ply layup from waxed paper to the heat duct/fuselage cabin floor. Nice >try, though, and for a while it really looked like it would work. I assume you're referring to the 7 ply layup over the center seat belt attach points. I have a vague recollection of doing pretty much what you describe (putting 7 layers on wax paper and then transferring it) and having it sit flat on the duct sides and the fuselage floor, but not bend nicely around the actual seat belt attach tube and the top corners of the duct. What I did was this: I cut the 7 layers in half (width wise) and laid them up so that the overlapped the 1 1/2 inches on top of the duct (so I've got 14 layers right on top of the tube). This allowed me to squish the 7 layers down around the corner and tube, and reshape them to fit. >Question: how best to do this layup so as to: > >1- get that "feathered edge" that Nat refers to I did this by varying the width of the 7 layers slightly from bottom to top and then peel plying the edges (remember, you can always sand a feather edge on if it's not perfect). >2- keep the weight (excess epoxy) down squeegee well in the wax-paper stage >3- get the air out squeegee well in the wax-paper stage, and then squeegee well after applying to the fuselage (not too hard though - then you just introduce more air). >without using spot vacuum bagging (becoming a better idea the longer I work >on this); a one- or two- inch brush, hairdryer and roller (where it fits)? I >dread doing those landing gear reinforcements in chapter nine. I just use brushes (for stippling), hairdryer (if my basement is below 80 deg F) and squeegees. I haven't found a real good use for rollers that doesn't seem to introduce more air than it removes. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Tue, 25 Jul 1995 11:41:14 -0400 From: Phillip.Johnson@Lockheed.on.ca (Phillip Johnson) Subject: seatbelt 7-ply reinforcements Norm Writes: > Question: how best to do this lay-up so as to: > 1- get that "feathered edge" that Nat refers to > 2- keep the weight (excess epoxy) down > 3- get the air out It was a long time ago that I did mine but as I remember I did not use wax paper. I laid up 7 individual plies, put a small amount of flox at the edges and peel plied the whole shooting match. The result was perfect feathered edges that will not peel. This is probably one area in which attention to detail with respect to the peeling properties should override the weight issues. Remember the peeling properties of our low temperature epoxy is not good at the best of times so play safe. Well I'm leaving for Oshkosh now so I'll hear from you in a week. Phillip Johnson Date: Sat, 5 Aug 1995 13:24:54 -0400 From: NBalog@aol.com Subject: Chapter 8 "extra" hdwr., brakes subject: "extra" hardware in chapter eight, and Cleveland super heavy duty brake set CWB199-152. First, chapter 8. Almost at the end of the chapter and I have a couple of left over screws, MS24694-S101 (2) and -S105 (2), plus a pair of AN525-416R14 machine screws. A month or so ago someone else mentioned this and no one had a specific reason for the extra parts. I do. I talked to Nat about this and we went over the section in the manual (chapter 8, page 3, figures 11-13. There's a note in figure 11 stating you should use AN509-416R18 and -416R14 thru the bracket and at ends, respectively. AN509 is the FORMER designation for MS24694 machine screws with a 100 degree countersunk head. Look at figure 13 and you'll see the outline of the countersunk holes in the step. In one of the newsletters there's a note to get a pair of AN525-416R18 machine screws for the center bolts on the step and, since these aren't available any more, I (like a lot of other people, I'm sure) ordered 416R20's. A little longer but they should work. I don't need them; I might though, depending on how I mount the step. According to Nat you have your choice of how to mount the step. Use the MS24694 -S101 and -S105 countersunk screws and countersink the step if you don't want the screw heads to show on the finished plane (for those of you chasing after Todd Morgan's trophies). Use the AN525 -R16 and -R20 if you think you might be "a little heavy and will need the extra support" on the outside of the step, the drag will be marginal and you won't notice them anyway (unless you're a judge who just got done looking at Todd's plane). Of course, you could try the countersunk set and replace them with the 525's if you're not satisfied. I may do this myself. I explained the potential confusion between the two sets of hardware that come with the "kit" (Wicks) and the Note on page 3 and suggested this make it into the next newsletter. He suggested we call him if we have questions, as I did. Good suggestion. NEXT Subject: Not to steal any of Nat's thunder, but in regard to the braking question, rather than generate any more unneccessary friction (pun intended... I better put a stop to that - ark ark - sorry, just testing your metal ) I won't bring up other possibilities not considered in this pseudo-scientific online discussion of braking effectiveness versus pilot error and just say Nat tells me he will devote some space in the next newsletter to this subject. There ARE other considerations. Don't shoot (or "flame") me, in the words of Marlon Brando I'm "just an errand boy." -Norm From: Lee Devlin Subject: Fuel valve clearance Date: Sat, 5 Aug 95 12:30:31 MDT I am currently on Chapter 6.2 and am about to install the keel/seat brace support. I noticed that the cutout in the seatback is only 1.5" wide where the fuel valve mounts but it needs to be to be wider (~2.5") in order to remove the fuel valve in the future. I looked ahead to chapter 21 (fuel system) and the hole shown there is wide enough there to remove the fuel valve through the front seat back. However, there's no mention in the plans to widen this slot before installing the keel/seat brace (or anywhere else that I can see). I think it would be much easier to do it now before I install the seat brace and was wondering what you guys did when you got to that part. Actually, I would like to install the valve later so as to keep it away from fiberglass dust as I work on the rest of the fuselage. This will only be possible if I widen the hole first. On a related matter, my keel is about .25" higher (fuselage upside down) than the longerons in its rear most location when the other portions of the keel are lined up with the bottoms of the instrument panel and seatback. (If you check the plans, this should be .1" higher as the longerons begin to curve around this point). Should this be sanded down so that the keel and longerons are all the same height, thus making the fuselage bottom completely flat from side to side? I'm not sure if this matters or will be completely impossible to detect one way or the other. Thanks, Lee Devlin Date: Sat, 5 Aug 1995 16:53:19 -0700 (PDT) From: Eric Westland Subject: Re: Fuel valve clearance Cut the fuel valve hole larger as you mention. I put mine in yesterday and had to widen it like you said. On Sat, 5 Aug 1995, Lee Devlin wrote: > I am currently on Chapter 6.2 and am about to install the keel/seat > brace support. I noticed that the cutout in the seatback is only 1.5" > wide where the fuel valve mounts but it needs to be to be wider (~2.5") > in order to remove the fuel valve in the future. I looked ahead to > chapter 21 (fuel system) and the hole shown there is wide enough there > to remove the fuel valve through the front seat back. However, there's > no mention in the plans to widen this slot before installing the > keel/seat brace (or anywhere else that I can see). I think it would be > much easier to do it now before I install the seat brace and was > wondering what you guys did when you got to that part. Actually, I > would like to install the valve later so as to keep it away from fiberglass > dust as I work on the rest of the fuselage. This will only be possible > if I widen the hole first. > > On a related matter, my keel is about .25" higher (fuselage upside down) > than the longerons in its rear most location when the other portions of > the keel are lined up with the bottoms of the instrument panel and > seatback. (If you check the plans, this should be .1" higher as the > longerons begin to curve around this point). Should this be sanded down > so that the keel and longerons are all the same height, thus making the > fuselage bottom completely flat from side to side? I'm not sure if this > matters or will be completely impossible to detect one way or the other. > > Thanks, > > Lee Devlin > From: Lee Devlin Subject: Chap 8 harness attach points Date: Mon, 13 Nov 95 8:47:58 MST I know this has be thrashed a while ago, but I am at the stage where I'm about to install the little plywood squares in which to mount the front seat harnesses. In April's newsletter, Nat issued a mandatory change to the harness attach points which reduced their spacing from 11.5" to 8.5" between centers. However, the headreast (a.k.a. rollover protection) is ~8" across at that point. Since the belt fitting extends out 1.5" from the mounting point, both sides of the passenger's headrest would need to be cut at the corners enough to severely reduce it's effectivness as a rollover structure. (I know that it's not truly a rollover structure for that reason, but I'm sure it helps.) It would also create an opportunity for the belt to chafe against the fiberglass groove. Needless to say, I'm really having a problem with this 'AD'. Is it legal posturing on Nat's part? In other words, is he using it to cover his company in the unlikely event that someone with a small passenger were to contact the ground in a inverted flat spin where the passenger came out of the straps? I know that many decisions (such as product recalls) are done with the intent to put the onerous of responsibility back on the owner. That is, if the owner fails to follow through on a manufacturer's recall (or in this case, mandatory change) the manufatcturer/designer is not at fault. If that's the case, I can't blame him, but I don't want to get chewed out by him if I elect not to follow through on this mandatory change. How 'strongly' does Nat feel about this change, that is, has he done it to his own Cozy? I have the harness assembly and there is an 'H' strap that crosses the chest that keeps the spacing (center to center) at approximately 5". I can see no way that a person can be ejected from this arrangement. I wish I knew more about the belts that were tested to find out if they had this 'H' strap. What are the opinions of other builders? Lee Devlin From: Lee Devlin Subject: Re: Chap 8 harness attach points Date: Tue, 14 Nov 95 17:53:11 MST I wrote: > How 'strongly' does Nat feel > about this change, that is, has he done it to his own Cozy? I just talked with Nat about this issue. He hadn't changed his plane yet because he was looking for the 'H' strap that came with his harness and found it (amazingly) today. He wanted to see if one could solve the problem by using the 'H' strap and he seemed to recall that the European seatbelt manufacturer did not have this extra web across the front. Perhaps the 'H' wed can be issued as an equivalent 'AD' if it is deemed sufficient. I also mentioned that the triangular headrest provided some rollover protection but failed to realize that unlike the LongEZ, the canopy also has a turtle deck and internal bulkhead which will probably afford more crashworthiness that the headrest anyway. The LongEZ did not have this internal bulkhead so cutting into the headrest would have been a more serious issue. I'll probably make the spacing of the attach points as close together as possible without having to cut into the headreast. Lee Devlin Date: Tue, 19 Dec 1995 23:03:32 -0500 From: Fritzx2@aol.com Subject: Re: 2024-t3 tubing for front seatbelt attach Steve Hall asked: >Hi everyone,,,,I am looking for a 4-6 inch piece of 3/8" x .065 wall of >2024-T3 used for the seat belt attach points Unless Wicks recently stopped selling the tubing, I think someone at Wicks gave you some bad information. I bought the tubing from Wicks in April of this year. No problem. I checked my invoice and it is item number R3/8X065-T3. They sold me a 6 inch cut piece. I would try again, afterall, it's toll free! In addition to the seatbelt attach point, you will need a piece of the same tubing for a pivot on the air brake mechanism used in the same chapter. From: Lee Devlin Subject: Re: 2024-t3 tubing for front seatbelt attach Date: Wed, 20 Dec 95 9:13:26 MST > > Steve Hall asked: > >Hi everyone,,,,I am looking for a 4-6 inch piece of 3/8" x .065 wall of > >2024-T3 used for the seat belt attach points > > Unless Wicks recently stopped selling the tubing, I think someone at Wicks > gave you some bad information. I bought the tubing from Wicks in April of > this year. No problem. > I checked my invoice and it is item number R3/8X065-T3. They sold me a 6 > inch cut piece. I would try again, afterall, it's toll free! In addition to > the seatbelt attach point, you will need a piece of the same tubing for a > pivot on the air brake mechanism used in the same chapter. I bought mine earlier this year as well, but I found that 6" is not enough since you have to cut it into three 2" pieces and the saw kerf eats some of it up. The last piece which I needed in Chapter 8 was only about 1.75" long and when I went to order more, they said it was no longer available :-(. I ended up using a lathe to drill out some solid 3/8" aluminum bar stock. I think this is one of those places where you could safely substitute another type of tubing without compromising the safety of the attach point. It's covered with 16 plies of fiberglass and the aluminum (when under load) is entirely in compression. Lee Devlin