Date: Tue, 21 Apr 1998 22:55:31 +0200 From: Rego and Noleen Burger Subject: COZY: Assembled weight 2c worth My ship tipped the scales @ 465lbs assembled raw airframe. Basic structure...nothing aft of the firewall and no equipment inside! Anyone else got a figure to compare? -- Rego Burger CZ4#139 South Africa Web:http://home.intekom.com/glen/rnb.htm Work e-mail, mailto:burgerr@telkom.co.za Date: Sat, 12 Sep 1998 22:15:13 -0500 From: "Joseph H. Hart IV" Subject: COZY: Builders' Weights on Marc's Website On Marc's website, the listed weights of F-28, for instance, vary from .7 to .8. Is this .7/.8 pounds or seven/eight ounces? If it's ounces, I'm in good shape. If it's pounds, mine is waaaay light! What's the story guys? Thanks, Jody Hart jodyhart@cmq.net Date: Sun, 13 Sep 1998 11:42:33 -0400 From: "Marc J. Zeitlin" Subject: Fwd: COZY: Builders' Weights on Marc's Website Joseph H. Hart IV asks; >On Marc's website, the listed weights of F-28, for instance, vary from >.7 to .8. Is this .7/.8 pounds or seven/eight ounces? If it's ounces, >I'm in good shape. If it's pounds, mine is waaaay light! What's the >story guys? As it says on the web page (right under the title) "All weights in pounds". 0.7 - 0.8 lbs. is 11 - 13 oz. If you came in a lot lighter than that, we should all be impressed (and you should check to make sure you didn't forget the epoxy :-). -- Marc J. Zeitlin                     marcz@ultranet.com 3 Sweetbriar Way                  http://www.ultranet.com/~marcz Acton, MA  01720                 http://cozy.canard.com/ Date: Sun, 13 Sep 1998 13:41:30 -0500 From: "Joseph H. Hart IV" Subject: Re: Fwd: COZY: Builders' Weights on Marc's Website Marc J. Zeitlin wrote: > If you came in a lot lighter than that, we > should all be impressed (and you should check to make sure you didn't > forget the epoxy :-). > It may be "impressive" but I'd feel a lot more comfortable if my weight matched the other builders' weights (F-28 that is!). I double checked to make sure I used the high-density .2" foam and not the .25" medium density. I used the right foam. I put 2 plys BID and 1 ply of UNI on each face. I weighed it before I did the foreward side lay-up and it weighed 5.3 oz. I felt that the aft side looked a little light -- although it doesn't have any air pockets, I think that I squeegeed too much because it feels a little rough from the glass. F-28 with the aft side only glassed weighed 5.3 oz. Final weight after both sides were glassed is 8.5 oz. Thus the foreward side layup w/micro weighs 3.2 oz. I peel plied the foreward side because of my conserns about the appearance of the aft side. I am certain that the foreward side has sufficient epoxy. I think that I need to get to the bottom of this before I move on as my part weighs approximately 25 percent less than others'. I don't think that there is anything wrong with my scale. It is brand new, electronic and has no user calibration feature. I have used it to weigh other things the approximate weight of which I already knew (within a tenth of an ounce), on which I base my assumption of accuracy. Does anyone know if MGS 285 is lighter than the other approved epoxies? I haven't seen any discussion of this on the list but, if it is lighter, it could make a substantial difference in final useful load. Any ideas as to whether I screwed up and, if so, how? Jody Hart jodyhart@cmq.net Cozy Mk IV plans #648 Chapter 4 P.S. I hope that I haven't been abusing my membership on the list by posting so many questions lately. I am sure that I will become more confident in short order and no longer be so reliant on all of you. In the meantime, thank you for your patience. P.P.S. Marc, I did see that it says "all weights in pounds" but, since my weight would have been right on the money had the measure after the decimal point been ounces instead of tenths of pounds, I thought I'd ask anyway just to make sure. Date: Sun, 13 Sep 1998 15:51:01 -0500 From: "Joseph H. Hart IV" Subject: Re: Fwd: COZY: Builders' Weights on Marc's Website Nat Puffer wrote: > How did this layup > compare with the theoretical weight, or didn't you do it? Nat: I did do the practice layup and its weight was on target. However, I have switched epoxies since the practice layup, which might make a difference in weight. Although my F-28 layups appear to be correct, I feel, and I think that you'll agree, that as much quality control as possible should be put in use, particularly at the beginning. Because my bulkhead is considerably lighter than what I understand others' to be, I feel that inquiry as to the reason is in order. Furthermore, although I am no chemist, it certainly seems possible that different epoxies with similar strenghts could have considerably different densities. Thus, if MGS is, in fact, lighter than the other approved epoxies, this would most likely be of interest to the group. I wasn't quite sure if you implied in your response to my posting that you don't put much faith in other builders' reported weights. Do you think that they should be ignored? I trust your opinion on these issues and will give others' weights less credence if you think that it is appropriate. It seems, however, that others' weights are a decent benchmark for my own. As expressed in an earlier posting, I acknowledge that I may be overly conservative/paranoid at this, beginning stage of construction. However, given the nature of this endeavor, I feel that my concerns are appropriate. Date: Mon, 14 Sep 1998 20:22:08 -0500 From: "Joseph H. Hart IV" Subject: COZY: Bulkhead weights resolved Thanks to all who responded to my earlier posts. I've now finished the seatback bulkhead, F-22 and F-28. I believe Lee Devlin may have provided the correct explanation for my low F-28 weight (8.3 oz./.5 lbs) -- I didn't add the cosmetic change to it that is optional in the plans. F-22 also came out a little light comparatively, at 2 lbs, 5 oz. or 2.3 lbs; however, it clearly passes inspection w/no entrapped air/delaminations/excessive weave roughness b/c of epoxy insufficientcy. I've concluded that the MGS, especially when used with a hair dryer, is very user/beginner friendly. Jody Hart jodyhart@cmq.net Cozy Mk IV, plans #648 1/2 way through Chapter 4 From: Greg and Jill Hilliard Subject: COZY: Early part weights Date: Mon, 14 Sep 1998 22:31:00 -0500 I sent these weights to the group some time ago, but they haven't found their way onto the web page yet. These parts are all vac bagged, wherever possible. seatback bulkhead 4.412# instrument panel bulkhead 3.936# f28 bulkhead 0.571# f22 bulkhead 2.173# forward landing gear bulkhead (lower) 1.245# forward landing gear bulkhead (upper) 0.699# aft landing gear bulkhead 2.439# firewall (lower) 2.657# firewall (middles) 0.608# firewall (upper) 3.173# fuselage side (port) 10.12# fuselage side (starboard) 10.10# heat duct-seat brace assy 2.916# Greg Hilliard gjhilliard@idcnet.com cozy mk4 #456 Date: Tue, 15 Sep 1998 08:26:31 +0200 From: Rego Burger Subject: COZY: Weights-WIngs I'm too scared to mention mine. Here goes: Unpainted, ailerons fitted without balance weights,winglets and rudders mounted. Tipped the scales @ 26kg each. This translates to 57,2 lbs per basic wing. If I add on 15% for finishing I hope to come out at 65,78 lbs per wing Max. Any other comparisons? Rego Burger Web site: http://home.intekom.com/glen/rnb.htm e-mail home- mailto:rnb@intekom.co.za RSA Date: Tue, 15 Sep 1998 21:49:22 -0400 From: "Marc J. Zeitlin" Subject: Fwd: COZY: Weights-WIngs Rego; >Unpainted, ailerons fitted without balance weights,winglets and rudders >mounted. >Tipped the scales @ 26kg each. >This translates to 57,2 lbs per basic wing. >If I add on 15% for finishing I hope to come out at 65,78 lbs per wing >Max. I don't remember my weights off the top of my head, but I do remember a discussion about them last year or the year before. Check the archives for weights or for chapter 19/20 - I know there were some postings from people regarding wing weights. PS - Rego, get rid of all the extra blank lines at the end of your signature file! :-). -- Marc J. Zeitlin marcz@ultranet.com http://www.ultranet.com/~marcz/ Date: Wed, 30 Dec 1998 21:05:31 -0500 Subject: COZY: Cozy IV bulkhead weights From: dhill36@juno.com (Dana Hill) Hi Cozies, FWIW here are the weights of my completed bulkheads, Marc please post if you'd like. ________Cozy IV____________ Seatback 5.9 ISP 4.5 (with foam removal in inst. area and addition of 5 plys of BID) F28 .7 F22 2.5 Fwd Lwr Lndg gear 1.7 Fwd Upr Lndg gear 1.0 Aft Lndg gear 3.1 Firewall- Lower 3.0 Firewall- Middles .9 Firewall- Upper 3.5 ________________________________________ Dana Hill CZ IV #676 Ch 5 ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866]