---------------------------------------------------------- Zenith701801-List Digest Archive --- Total Messages Posted Wed 03/03/10: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:55 AM - Re: Substituting .016 for .020 on the skins? (Stanley A Challgren) 2. 08:29 PM - Substituting 020 for 016 (Joe Spencer) 3. 08:40 PM - Re: Substituting 020 for 016 (Joe Spencer) 4. 11:55 PM - Re: Re: Substituting 020 for 016 (JG) ________________________________ Message 1 _____________________________________ Time: 09:55:22 AM PST US From: Stanley A Challgren Subject: Re: Zenith701801-List: Substituting .016 for .020 on the skins? Joe: I did not use a 1 X 4 which is a great idea but did find near the end of the building process that rolling up the .016 skin each time it was taken off the aircraft made the process go a lot easier. After rolling it up I used bungee cords to keep it rolled up. The result was no more smilies and a lot fewer bad words. I like your reported 579# and 97 mph cruise with VG's. My estimate for N701VG on weight and cruise is about the same with the VG's. Stan 701/3300 On Mar 2, 2010, at 11:55 , Joe Spencer wrote: > My 701/912s/VG weighs 579# empty with strut cuffs and other cleanup fairings...it's a heckuva good performer; the takeoff and climbout when solo and light on gas is shocking. I can't imagine compromising any of that performance to the least degree especially for subbing 020 for 016. There isn't any reliability issue associated with the 016 skin that I'm aware of, the oil canning is a non issue...you get used to it and it tells you when it's not coordinated, and there was no difficulty handling the sheets by myself while building. Just clamp a 1x4 along the edge and pick it up and move it. Mine has a TXP, Encoder, Comm, GPS, paint and light simple upholstery...the only other things I allowed myself were the cleanup fairings that more than paid for their weight in reduced drag(or I would have removed them). It cruises 97 mph at 5000 rpm down low with the Warp Drive set at a thin 11 degrees. I don't think you'll find any of the heavy ones that will do that...not if the performance has been accurately measured. > Once it's built so it'll stay together weight is everything else...well nearly so. 30# for thicker skin is huge and pointless > > Joe > > ________________________________ Message 2 _____________________________________ Time: 08:29:03 PM PST US From: "Joe Spencer" Subject: Zenith701801-List: Substituting 020 for 016 >Joe: >I did not use a 1 X 4 which is a great idea but did find near the end of >the building process that rolling up the .016 skin each time it was >taken off the aircraft made the process go a lot easier. After rolling >it up I used bungee cords to keep it rolled up. The result was no more >smilies and a lot fewer bad words. >I like your reported 579# and 97 mph cruise with VG's. My estimate for >N701VG on weight and cruise is about the same with the VG's. >Stan Right, Stan...there must be all sorts of ways to handle the 016 skins w/o damage besides resorting to 020. Further thoughts on the thicker skins solution suggested by some here...the reference to the 020 on the 750 probably is probably hardly relevant to the 701; that's a larger plane with higher gross weight. Zenith I feel sure went to the thicker skins because of a load requirement which doesn't apply to our smaller, lighter plane. Some mentioned the 020 would make it stronger...we already have a +4G/+6G (yield) design; why would we possibly need more strength...we're mostly just a bunch of old farts motoring around and landing in cow pastures and beaches and such. If we were in a fast mover trying to dodge SAMs over Hanoi or Bagdad or somewhere well maybe yeah...Zenith has already designed the thing for our typical mission; why add needless weight? I work my butt off trying to save a pound or two here and there. To add 30 needless pounds is unthinkable to me. I realize that to some the building process is more important than the finished product; me, I want a light good performing machine and realize that minimum weight and least drag are all important...Bolding and JG got it right Best Joe ________________________________ Message 3 _____________________________________ Time: 08:40:24 PM PST US From: "Joe Spencer" Subject: Zenith701801-List: Re: Substituting 020 for 016 I did not use a 1 X 4 which is a great idea but did find near the end of >the building process that rolling up the .016 skin each time it was >taken off the aircraft made the process go a lot easier. After rolling >it up I used bungee cords to keep it rolled up. The result was no more >smilies and a lot fewer bad words. >I like your reported 579# and 97 mph cruise with VG's. My estimate for >N701VG on weight and cruise is about the same with the VG's. >Stan Right, Stan...there must be all sorts of ways to handle the 016 skins w/o damage besides resorting to 020. Further thoughts on the thicker skins solution suggested by some here...the reference to the 020 on the 750 probably is probably hardly relevant to the 701; that's a larger plane with higher gross weight. Zenith I feel sure went to the thicker skins because of a load requirement which doesn't apply to our smaller, lighter plane. Some mentioned the 020 would make it stronger...we already have a +4G/+6G (yield) design; why would we possibly need more strength...we're mostly just a bunch of old farts motoring around and landing in cow pastures and beaches and such. If we were in a fast mover trying to dodge SAMs over Hanoi or Bagdad or somewhere well maybe yeah...Zenith has already designed the thing for our typical mission; why add needless weight? I work my butt off trying to save a pound or two here and there. To add 30 needless pounds is unthinkable to me. I realize that to some the building process is more important than the finished product; me, I want a light good perfor! ming machine and realize that minimum weight and least drag are all important...Bolding and JG got it right Best Joe ________________________________ Message 4 _____________________________________ Time: 11:55:05 PM PST US Subject: Re: Zenith701801-List: Re: Substituting 020 for 016 From: JG *Increasing the skin thickness by 25% does not increase the strength of an aircraft like the 701 by 25%, it's just dead weight. Many years ago I knew a 701 built with .020, along with a few other 'strengthening' mods considered essential by the amateur builder, and a heavy Subaru engine. The flying performance was a complete disappointment to the builder - it was the classic 'lead sled' just as Bolding predicts.... * * * *That short 701 wing was originally designed for a much lighter 701, with a 2-stroke engine. Since then it's gained a lot of weight, with no more wing. Beware of adding any more weight at all to this aircraft....... * * * *I have experience in rebuilding three very bent 701's that had come to grief on perilous short strips. In no instance would .020 been an advantage to the result. The wings and fuselage on the 701 are excellent at crumpling in just the right places to absorb the impact energy, and so protect the occupants and the rest of the aircraft from damage. * * * *The oil canning issue is easily fixed. Just add .016 angle in the rear fuselage, and intermediate foam ribs in the wings. Both stuck in with Sikkaflex or similar polyurethane adhesive. Using the adhesive instead of rivets is easier, and leaves a more fair surface. This adhesive needs to have a thick bead to cure properly, so cut the ribs 2-3mm smaller. When the wing is ready to close, put a good bead of adhesive on the underside of the foam ribs and set them in place and let the adhesive cure. Check with a straight edge to see that the upper edges of the foam ribs are just below the aluminum ribs. Then put a thick bead of adhesive on the top edges, and rivet the top skins in place. The adhesive will take up any gap and adapt to the contour of the skin. When it's cured it will hold the skin in place even better than rivets. Using 10mm (3/8") close-cell polyurethane foam (same as used by the fiberglass industry), the weight is probably only 1 lb for the whole aircraft, and very effective.* * * *Once again - If you want good STOL performance, beware of adding any extra weight to the 701........* * * *JG * On Thu, Mar 4, 2010 at 2:36 PM, Joe Spencer wrote: > I did not use a 1 X 4 which is a great idea but did find near the end of > >the building process that rolling up the .016 skin each time it was > >taken off the aircraft made the process go a lot easier. After rolling > >it up I used bungee cords to keep it rolled up. The result was no more > >smilies and a lot fewer bad words. > > >I like your reported 579# and 97 mph cruise with VG's. My estimate for > >N701VG on weight and cruise is about the same with the VG's. > > >Stan > > Right, Stan...there must be all sorts of ways to handle the 016 skins w/o > damage besides resorting to 020. > Further thoughts on the thicker skins solution suggested by some here...the > reference to the 020 on the 750 probably is probably hardly relevant to the > 701; that's a larger plane with higher gross weight. Zenith I feel sure went > to the thicker skins because of a load requirement which doesn't apply to > our smaller, lighter plane. Some mentioned the 020 would make it > stronger...we already have a +4G/+6G (yield) design; why would we possibly > need more strength...we're mostly just a bunch of old farts motoring around > and landing in cow pastures and beaches and such. If we were in a fast mover > trying to dodge SAMs over Hanoi or Bagdad or somewhere well maybe > yeah...Zenith has already designed the thing for our typical mission; why > add needless weight? I work my butt off trying to save a pound or two here > and there. To add 30 needless pounds is unthinkable to me. I realize that to > some the building process is more important than the finished product; me, I > want a light good perfor! > ming machine and realize that minimum weight and least drag are all > important...Bolding and JG got it right > Best > Joe > > * > > * > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith701801-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith701801-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/zenith701801-list Browse Digests http://www.matronics.com/digest/zenith701801-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.