---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Tue 11/13/07: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 12:23 AM - List of Contributors (Matt Dralle) 1. 03:05 AM - Re: Re: Leading airfoil shape-- scalloped back edge (HelsperSew@aol.com) 2. 04:25 AM - Re: Re: Leading airfoil shape-- scalloped back edge (Phillips, Jack) 3. 04:36 AM - Re: Re: Leading airfoil shape-- wood vs. metal (Phillips, Jack) 4. 05:15 AM - Re: Leading airfoil shape-- wood vs. metal (jimd) 5. 01:42 PM - Re: Re: Leading airfoil shape-- scalloped back edge (Scott Schreiber) ________________________________ Message 0 _____________________________________ Time: 12:23:17 AM PST US From: Matt Dralle Subject: Pietenpol-List: List of Contributors Each year at the end of the List Fund Raiser, I post a message acknowledging everyone that so generously made a Contribution to support the Lists. Its sort of my way of publicly thanking everyone that took a minute to show their appreciation for the Lists. Won't you take a moment and assure that your name is on that List of Contributors (LOC)? As a number of members have pointed out over the years, the List seems at least - if not a whole lot more - valuable as a building/flying/recreating/entertainment tool as your typical magazine subscription! Please take minute and assure that your name is on this year's LOC! Show others that you appreciate the Lists. Making a Contribution to support the Lists is fast and easy using your Credit card or Paypal on the Secure Web Site: http://www.matronics.com/contribution or by popping a personal check in the mail to: Matt Dralle / Matronics PO Box 347 Livermore CA 94551-0347 I would like to thank everyone that has so generously made a Contribution thus far in this year's List Fund Raiser! Remember that its YOUR support that keeps these Lists going and improving! Don't forget to include a little comment about how the Lists have helped you! Best regards, Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 03:05:11 AM PST US From: HelsperSew@aol.com Subject: Re: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge Guys, Since I tried to "make it better" by supporting and nailing down the aft edge of the 1/16" plywood, I think I will cut the scalloped edge, simply because it will be easier to cut away my "improvement"! This was done before I discovered this list. Very helpful!!! Dan Helsper Poplar Grove, IL. ________________________________ Message 2 _____________________________________ Time: 04:25:29 AM PST US Subject: RE: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge From: "Phillips, Jack" Neat idea with the Clorox bottle strips, Walt. I cut thin strips of spruce and nailed through them, and they were a pain in the butt. They split easily, and I had to use waxed paper to keep the glue from sticking to them. Your idea is much better. Jack Phillips -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of walt evans Sent: Monday, November 12, 2007 6:03 PM Subject: Re: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge Here's pics of mine. Cut strips of a kitty litter bottle, or can use clorox bottle. Staple thru it. when dry pull off the strips. Glue doesn't stick to the strips. walt evans NX140DL "No one ever learned anything by talking" Ben Franklin ----- Original Message ----- From: "walt evans" Sent: Monday, November 12, 2007 4:44 PM Subject: Re: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge > > I don't think anywhere in the plans it calls out to scallop the skin. > It was said that just the straight trailing edge of the thin ply pulls > down nicely when covered. > If you stiffen the trailing edge you'll create a step. > Mine came out very well un scalloped and unsupported > walt evans > NX140DL > > "No one ever learned anything by talking" > Ben Franklin > ----- Original Message ----- > From: "Tim Willis" > To: > Sent: Monday, November 12, 2007 8:39 AM > Subject: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge > > >> >> >> While we are discussing putting thin plywood on the face of the wings to >> shape the airfoil, what about the scalloped rear edge of any such >> plywood skins? >> I know this is a long way in sophistication from Mother's Oats stuff >> first used by BP, but is it a real improvment? What does it really do? >> I understand the concept of the fabric lifting between the scallops while >> in flight, but what do the scallops really do? >> >> I plan to put 1/16" or 1.5mm ply skin on the airfoil face, but I'd like >> to avoid effecting these scallops unless they really change performance. >> Your comments, pls. >> >> (I hope I am being clear enough in describing this.) >> >> Tim in central TX >> >> =========================================== >>>> [EXCERPT-- Tim] >>>> Don't do it as one big piece.. thought about putting plywood airfoil >>>> shaped pieces on each rib, with about a one inch square opening for a >>>> piece of wood, then I could use longeron stock. Would end up lighter, >>>> could do with jigsaw and files. However it wouldn't provide much >>>> support >>>> to the leading edge skin as it would only make contact at each rib. >>>> >>>> This is for a GN-1 Biplane, which confuses the issue a little. The top >>>> wings are complete, they have a .026 aluminum wrapped leading edge with >>>> a >>>> square 1" spar that touches the leading edge in two spots the full >>>> length >>>> of the wings. (The square part is along the very front of each rib) so >>>> it >>>> provides some support.) >>>> >>>> The lower wing is what needs the spars, and then to be skinned with >>>> something. My plans show a single piece of wood shaped to match the >>>> airfoil profile, attached via flat head machine screws/bolts, at each >>>> rib. >>>> There is no indication of wood or aluminum for leading edge skin. Since >>>> my >>>> top wings have aluminum, and I am comfortable working with it I was >>>> leaning toward skinning it with aluminum. >>>> >>>> Preference would be to follow plans, which would be to make up an >>>> airfoil >>>> shaped spar. How did you guys do this? >>>> >>>> I have a picture (not my plane, but same exact kind of shaped piece) as >>>> an >>>> example of what I think I need. >>>> >>>> Any help would be appreciated. >>>> >>>> Jim >>>> >>>> >>> >> >> >> >> >> >> > > > _________________________________________________ or otherwise private information. If you have received it in error, please notify the sender Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - Norsk - Portuguese ________________________________ Message 3 _____________________________________ Time: 04:36:12 AM PST US Subject: RE: Pietenpol-List: Re: Leading airfoil shape-- wood vs. metal From: "Phillips, Jack" Chuck is absolutely right. Aluminum is actually more difficult to install than the plywood, adds nothing to the strength and gets dented easier. It is also heavier. Other than all those items, it is great. I seriously considered aluminum for my leading edge. I used aluminum trailing edges and wish I had used wood like the plans show. Build it per the plans and you won't be sorry. "Improve it" and it might be better, but probably will be heavier and more difficult to build. Jack Phillips NX899JP _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Rcaprd@aol.com Sent: Monday, November 12, 2007 10:25 PM Subject: Re: Pietenpol-List: Re: Leading airfoil shape-- wood vs. metal In a message dated 11/12/2007 9:17:39 PM Central Standard Time, brian.kraut@engalt.com writes: The GN-1 plans show .013" aluminum sheet on the leading edge. The aluminum will cost less and be easier to install. Aluminum leading edges also get dented up a lot easier than the plywood. Any opinions on which is better? Brian, I still much prefer the plywood, because I don't think it is any more difficult to install than aluminum, it is more durable than aluminum - as you mentioned, and because wood and aluminum have different expansion rates with temperature changes - which may cause some wavy looks, or loosen the nails in the aluminum. Chuck G. NX770CG _____ See what's new at our http://www.matronics.com/Navigator?Pietenpol-List =========== _________________________________________________ This message is for the designated recipient only and may contain privilege d, proprietary or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is p rohibited. Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - N orsk - Portuguese ________________________________ Message 4 _____________________________________ Time: 05:15:39 AM PST US Subject: Pietenpol-List: Re: Leading airfoil shape-- wood vs. metal From: "jimd" I had same question a while ago. My top wing is GN-1 and has .026 aluminum, with the brass coated nails. However it sat a long time in AZ and the nails were pulling out. Consensus seems to be that wood is better, stiffer and it expands/contracts more like the wood in the wings. Think in my case I will end up using aluminum for bottom wing as it would look odd to do one aluminum, other wood, and I am more comfortable working with aluminum. (Lived in Wichita, KS, took sheet metal classes thinking I might need them to work at Beechcraft/Boeing or Cessna ... fortunately career went other direction.) Did see a nice tip on cutting sheet metal (light gage only) you can score it with a hobby mat cutter a few times and get a clean line. Then bend it till it comes clean off. Much easier to get a mat cutter than a good 8-10ft metal shear. Snips make a pretty rough edge too. Jim Read this topic online here: http://forums.matronics.com/viewtopic.php?p=145686#145686 ________________________________ Message 5 _____________________________________ Time: 01:42:08 PM PST US From: "Scott Schreiber" Subject: Re: Pietenpol-List: Re: Leading airfoil shape-- scalloped back edge How timely! I was just starting on this part myself and you just illustrated everything I was uncertain about on the leading edge sheet. -Scott ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-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/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-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.