---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Mon 11/14/11: 21 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:28 AM - Re: Wing rib profile questions (Jack) 2. 04:48 AM - Re: Wing rib profile questions (jarheadpilot82) 3. 05:03 AM - Re: Wing rib profile questions (j_dunavin) 4. 05:15 AM - Re: Wing rib profile questions (Bill Church) 5. 05:44 AM - Re: Wing rib question (Gene Rambo) 6. 07:18 AM - Re: Wing rib question (Michael Perez) 7. 07:31 AM - Re: Undercamber (Woodflier@aol.com) 8. 07:33 AM - Re: Wing rib question (Don Emch) 9. 07:33 AM - RE : Under camber (Woodflier@aol.com) 10. 08:11 AM - Re: Douwe Blumberg (bender) 11. 08:29 AM - Re: Wing rib question (Bill Church) 12. 10:21 AM - Re: Wing rib question (K5YAC) 13. 11:29 AM - Re: Wing rib question (TOM STINEMETZE) 14. 11:41 AM - Re: Wing rib question (Bill Church) 15. 11:54 AM - Re: Wing rib question (K5YAC) 16. 01:19 PM - Re: Re: Wing rib question (Jim Markle) 17. 03:00 PM - Re: Wing rib question (K5YAC) 18. 04:50 PM - Corvair engines for sale-ABE (Pocono John) 19. 05:05 PM - Re: Re: Wing rib question (Ryan Mueller) 20. 07:02 PM - Re: Re: Wing rib question (Steve Emo) 21. 08:10 PM - Re: RE : Under camber (Clif Dawson) ________________________________ Message 1 _____________________________________ Time: 03:28:00 AM PST US From: "Jack" Subject: RE: Pietenpol-List: Wing rib profile questions I labored over this same issue for weeks. I lofted the measurements, traced existing ribs from other builders and compared with the full-size prints. The differences were very small. In the end, I averaged the lofted drawing and full size print. If I remember correctly the difference was most pronounced in the top front of the airfoil. It's one of those times in the process you just need to make your decision and get going. Jack DSM N1929T -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of j_dunavin Sent: Sunday, November 13, 2011 8:43 PM Subject: Pietenpol-List: Wing rib profile questions I'm ready to make my wing rib jig and would like to use the 1:1 print that we ordered with the plans. I would like to take a razor, cut it out, and then trace around it for the jig. However I got to looking at the plans and then I started taking measurements on the 1:1 drawing, and it does not seem to match. Should i not worry about it? Should i draw the rib on my jig, as per the plans? Thanks Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357786#357786 ________________________________ Message 2 _____________________________________ Time: 04:48:20 AM PST US Subject: Pietenpol-List: Re: Wing rib profile questions From: "jarheadpilot82" Is the difference consist at every measurement? If so, then your rib plan needs to be proportionally resized. You can go to any Kinko's/Fedex Office, and they can do it. Simply ask them to reprint your plan at 102%, 105%, 107% or whatever it needs to be. Or do like Jack says, live with the small difference, and build on. -------- Semper Fi, Terry Hand Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357800#357800 ________________________________ Message 3 _____________________________________ Time: 05:03:20 AM PST US Subject: Pietenpol-List: Re: Wing rib profile questions From: "j_dunavin" No, Jack is right. Most of the difference is in the front of the wing, and it is small differences. I think that I will draw out the wing in Auto Cad, and then place the two side by side and see what gives. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357801#357801 ________________________________ Message 4 _____________________________________ Time: 05:15:54 AM PST US Subject: Pietenpol-List: Re: Wing rib profile questions From: "Bill Church" If you're comfortable with a pencil and ruler and a square, it only takes about an hour to loft the rib plan onto a nice flat piece of wood (I used MDF, but good quality plywood will work as well). If you're not so handy at drafting, before deciding to just "live with the small difference", the most important dimension to check on your full size rib plot is the spar-to-spar dimension. If using the full-size plot, why would you want to cut out the rib profile with a razor? Just leave it as is, and use spray adhesive to glue the whole plot to the board, then add positioning blocks on top of the paper, as needed. If you cut the plan into a narrow strip of paper, you are more likely to end up with distortions in the rib profile, since a long narrow strip of paper is less stable than a wider strip. Bill C. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357802#357802 ________________________________ Message 5 _____________________________________ Time: 05:44:48 AM PST US From: Gene Rambo Subject: RE: Pietenpol-List: Wing rib question I have to take issue with the comment that an airfoil with undercamber is " a pain to cover." It may be=2C only if it is overthought=2C not that this ever happens on this list! I have heard of guys worrying about gluing to t he bottom of each rib=2C etc. The truth is=2C just cover the wing normally . When the fabric is shrunk=2C there is only a very little gap off of the bottom capstrip. the ribstitching pulls it right down with no problem what soever. End of problem. Genedo not archive Date: Sun=2C 13 Nov 2011 17:48:32 -0800 From: n11dmx@yahoo.com Subject: Re: Pietenpol-List: Wing rib question John=2C Just finished my r wing.=2C all my ribs are done. I made matching 2 x 4 blocks with the curve =2Csoaked the ACS cap strips in water over night and then clamped them in the "molds" for 24 hrs worked fine. Also took out the under camber (a pain to cover.) I made an outline of the rib on a flat table and used small blocks on both sides of the cap strip here and there. Put the outside blocks on the line =2C butspace the inside block about 1/8 ich off the inside line. Take apart these spring loaded clothespins and you have nice little wedges this will accomadate small variations in cap strip thickness. Dave Millikan Starduster Too N11DM and Pete NX1QZ --- On Mon=2C 11/14/11=2C John Theron wrote: From: John Theron Subject: Pietenpol-List: Wing rib question Has anyone had cause to pre bend the lower wing rib section forward of the front spar or have pre bent it anyway? John ollow target=_blank>www.aeroelectric.com /" rel=nofollow target=_blank>www.buildersbooks.com ofollow target=_blank>www.homebuilthelp.com llow target=_blank>http://www.matronics.com/contribution " rel=nofollow target=_blank>http://www.matronics.com/Navigator?Pietenp ol-List et=_blank>http://forums.matronics.com llow target=_blank>http://www.matronics.com/contribution ________________________________ Message 6 _____________________________________ Time: 07:18:33 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Wing rib question My ribs are the Riblett 612 type. I did not soak or pre-bend my bottom rib cap strips. However, this airfoil has a more gentle curve underneath. - I chose to soak my top cap strip and then place it in a pre-bend jig and th en finally place it in the rib build jig. I see no issue going from the soa ker right to the build jig. (Skipping the pre-bend.) - Not sure, but I seem to remember talk about the full size rib plan having a slight flat spot somewhere on the top as compared to the speced-out pictur e on the plans. Or something to that effect. Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 7 _____________________________________ Time: 07:31:17 AM PST US From: Woodflier@aol.com Subject: Pietenpol-List: Re: Undercamber I agree with ________________________________ Message 8 _____________________________________ Time: 07:33:11 AM PST US Subject: Pietenpol-List: Re: Wing rib question From: "Don Emch" Gene... can't agree with you more. Just like any other wing. The rib stitching will pull it in. Totally a non issue. The undercamber is a key to its low speed characteristics. Same reason the Aeroncas and many others have a very slight undercamber. Don Emch NX899DE Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357817#357817 ________________________________ Message 9 _____________________________________ Time: 07:33:22 AM PST US From: Woodflier@aol.com Subject: Pietenpol-List: RE : Under camber I agree with John. Without the under camber, it's a different airfoil. Might have better characteristics - might have worse but it's different. I didn't find covering the undercamber difficult if you follow the instructions in the PolyFiber manual. And, the under camber is a conversation piece. Matt Paxton ________________________________ Message 10 ____________________________________ Time: 08:11:35 AM PST US Subject: Pietenpol-List: Re: Douwe Blumberg From: "bender" Wow.... Douwe... i'm impressed... beautiful work.. i looked at your website...i had no idea such a great artist lived so near jeff Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357825#357825 ________________________________ Message 11 ____________________________________ Time: 08:29:52 AM PST US Subject: Pietenpol-List: Re: Wing rib question From: "Bill Church" Gotta say that changing something as critical as the airfoil, just because one thinks it will be "a pain to cover" sounds like a drastic course of action to take, with unknown consequences. Sure hope that anyone considering such a move would do all of the necessary homework to anticipate all of the repercussions that would result. On another note, Michael, you say that the Riblett 612 has a gentler curve underneath than the Pietenpol FC-10 airfoil. I agree that the undercamber is less severe, but I believe that there is MORE curvature towards the nose of the rib (see attached comparison of the two airfoils). Whether this requires pre-bending is another question. Sounds as though some builders have felt it necessary and some have not. Personally, I built the Pietenpol FC-10 ribs, and did not need to pre-bend the lower capstrips. Bill C. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357827#357827 Attachments: http://forums.matronics.com//files/fc10_vs_ga30ua612_150.pdf ________________________________ Message 12 ____________________________________ Time: 10:21:15 AM PST US Subject: Pietenpol-List: Re: Wing rib question From: "K5YAC" FWIW... I pre-soaked/bent my top and bottom capstrip. Not sure if it was necessary for the bottoms, but it was a matter of cutting a simple form from a scrap 2x6 and clamping a batch in place every few days when I was building ribs. Had to do it for the top caps anyway, so I doubt that it added much to my overall effort. I will say that I didn't have to fight any of the caps on my jig, and the ribs came out as near to identical as I can tell. If I were to do it over, I would do it the same. As for ease of covering... in the early stages of planning I was considering a cylindrical wing. No bends, no curves, no corners, no sharp edges and I could just roll them out of the way when I wasn't working on them... the ideal covering job. But, it got very complicated on the drawing board because I kept confusing the LE and TE. Not sure how it might have flown, but hey, at least the covering would have been easy. -------- Mark Chouinard Wings, Center Section and Empannage framed up - Working on Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357839#357839 ________________________________ Message 13 ____________________________________ Time: 11:29:22 AM PST US From: "TOM STINEMETZE" Subject: Pietenpol-List: Re: Wing rib question I built a simple pre-soaking rig out of a 2' piece of 2" galvanized pipe with a cap on one end only. I drilled a hole on the top end and hung the pipe over my kerosene shop heater. Worked like magic and I did not bother with prebending - just went right into the jig after wiping off the excess moisture. I was worried that the water soaked joints might not glue up correctly so I made some test pieces just to check. The tests did not seem any different between the soaked pieces and the dry ones. I did discover one problem later on though. I made a couple of extra ribs about 3-years later using the same pipe. The spruce came out of the pipe just as plyable but stained a dark grey. Not unattractive but they are sure going to stand out from the rest. Oh yeah, I only soaked the top piece as the bottom went in the jig dry without any difficulty. P.S. Congratulations Shad! Tom Stinemetze N328X >>> "K5YAC" 11/14/2011 12:18 PM >>> FWIW... I pre-soaked/bent my top and bottom capstrip. Not sure if it was necessary for the bottoms, but it was a matter of cutting a simple form from a scrap 2x6 and clamping a batch in place every few days when I was building ribs. Had to do it for the top caps anyway, so I doubt that it added much to my overall effort. I will say that I didn't have to fight any of the caps on my jig, and the ribs came out as near to identical as I can tell. If I were to do it over, I would do it the same. ________________________________ Message 14 ____________________________________ Time: 11:41:35 AM PST US Subject: Pietenpol-List: Re: Wing rib question From: "Bill Church" Here's a picture of Mark sitting in his mock-up: BC do not archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357850#357850 Attachments: http://forums.matronics.com//files/cylinder_128.jpg ________________________________ Message 15 ____________________________________ Time: 11:54:18 AM PST US Subject: Pietenpol-List: Re: Wing rib question From: "K5YAC" It almost worked. -------- Mark Chouinard Wings, Center Section and Empannage framed up - Working on Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357851#357851 ________________________________ Message 16 ____________________________________ Time: 01:19:51 PM PST US From: Jim Markle Subject: Re: Pietenpol-List: Re: Wing rib question Should have gone with the wood fuse.... -----Original Message----- >From: Bill Church >Sent: Nov 14, 2011 1:39 PM >To: pietenpol-list@matronics.com >Subject: Pietenpol-List: Re: Wing rib question > > >Here's a picture of Mark sitting in his mock-up: > >BC > >do not archive > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=357850#357850 > > >Attachments: > >http://forums.matronics.com//files/cylinder_128.jpg > > ________________________________ Message 17 ____________________________________ Time: 03:00:56 PM PST US Subject: Pietenpol-List: Re: Wing rib question From: "K5YAC" I did go with a wood fuse... I just "Perez'd" the longerons and braces by rounding them to give the impression of steel tube, therefore offering the worst qualities I possibly could... heavier AND less strength. Just kidding Mike. -------- Mark Chouinard Wings, Center Section and Empannage framed up - Working on Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357867#357867 ________________________________ Message 18 ____________________________________ Time: 04:50:33 PM PST US Subject: Pietenpol-List: Corvair engines for sale-ABE From: "Pocono John" There's a couple of engines for sale in Allentown, PA. Send me a note if you want the contact info. One engine is a '65 RH. The other is a RM however, he also has 110 heads you can use to swap out with. As a matter of fact, being a big collector of Corvair's, he has a lot of parts around. I may be slow to respond if you write, but I will respond. Below are pictures I took, first the RH then the RM. The photos are in reverse order from the way I added them, so look at the file name to verify if you're looking at the RM or RH. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=357883#357883 Attachments: http://forums.matronics.com//files/rm4_573.jpg http://forums.matronics.com//files/rm3_191.jpg http://forums.matronics.com//files/rm2_158.jpg http://forums.matronics.com//files/rm1_106.jpg http://forums.matronics.com//files/rh4_402.jpg http://forums.matronics.com//files/rh3_194.jpg http://forums.matronics.com//files/rh2_179.jpg http://forums.matronics.com//files/rh1_144.jpg http://forums.matronics.com//files/corvair_shed_162.jpg ________________________________ Message 19 ____________________________________ Time: 05:05:36 PM PST US Subject: Re: Pietenpol-List: Re: Wing rib question From: Ryan Mueller Alter the airfoil Now you are the test pilot Good luck and godspeed DO NOT ARCHIVE On Mon, Nov 14, 2011 at 10:27 AM, Bill Church wrote: > billspiet@sympatico.ca> > > Gotta say that changing something as critical as the airfoil, just because > one thinks it will be "a pain to cover" sounds like a drastic course of > action to take, with unknown consequences. Sure hope that anyone > considering such a move would do all of the necessary homework to > anticipate all of the repercussions that would result. > > On another note, Michael, you say that the Riblett 612 has a gentler curve > underneath than the Pietenpol FC-10 airfoil. I agree that the undercamber > is less severe, but I believe that there is MORE curvature towards the nose > of the rib (see attached comparison of the two airfoils). Whether this > requires pre-bending is another question. Sounds as though some builders > have felt it necessary and some have not. > > Personally, I built the Pietenpol FC-10 ribs, and did not need to pre-bend > the lower capstrips. > > Bill C. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=357827#357827 > > > Attachments: > > http://forums.matronics.com//files/fc10_vs_ga30ua612_150.pdf > > ________________________________ Message 20 ____________________________________ Time: 07:02:04 PM PST US From: Steve Emo Subject: Re: Pietenpol-List: Re: Wing rib question And aero engineer to that list because you also will alter the center of pre ssure, etc. So Don't be surprised if you also where the CG is located and w here the new CG limits should be. May I suggest some wind tunnel tests or s ome good CFD models, Fluent has some good code that can do this, rather salt y in price. Sent from my iPhone On Nov 14, 2011, at 8:02 PM, Ryan Mueller wrote: > Alter the airfoil > Now you are the test pilot > Good luck and godspeed > > DO NOT ARCHIVE > > On Mon, Nov 14, 2011 at 10:27 AM, Bill Church wro te: a> > > Gotta say that changing something as critical as the airfoil, just because one thinks it will be "a pain to cover" sounds like a drastic course of act ion to take, with unknown consequences. Sure hope that anyone considering su ch a move would do all of the necessary homework to anticipate all of the re percussions that would result. > > On another note, Michael, you say that the Riblett 612 has a gentler curve underneath than the Pietenpol FC-10 airfoil. I agree that the undercamber i s less severe, but I believe that there is MORE curvature towards the nose o f the rib (see attached comparison of the two airfoils). Whether this requir es pre-bending is another question. Sounds as though some builders have felt it necessary and some have not. > > Personally, I built the Pietenpol FC-10 ribs, and did not need to pre-bend the lower capstrips. > > Bill C. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=357827#357827 > > > > > Attachments: > > http://forums.matronics.com//files/fc10_vs_ga30ua612_150.pdf > > > > > ========== > ="_blank">www.aeroelectric.com > ooks.com" target="_blank">www.buildersbooks.com > et="_blank">www.homebuilthelp.com > ="_blank">http://www.matronics.com/contribution > le, List Admin. > ========== > st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 21 ____________________________________ Time: 08:10:09 PM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: RE : Under camber So why does the "FC-10" airfoil have this undercamber anyway? After all, it is a bit more difficult to build ribs and cover the wing. Do you really think someone as smart as BP would do this if he hadn't found it necessary? The undercamber makes for a lot more slow speed lift. Something to compensate for the Fords low horsepower. He built and tested a number of wings with other airfoils. None were satisfactory. This one was. Here's a little something from our esteemed Transport Canada that you can play with. We all assume that the Ford is forty hp but apparently not; http://www.amuffler.com/dyno/dyno1.htm Clif I agree with John. Without the under camber, it's a different airfoil. Might have better characteristics - might have worse but it's different. Matt Paxton No virus found in this message. Checked by AVG - www.avg.com 11/13/11 ------------------------------------------------------------------------------------- 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.