Original Posted By: "DJ Vegh"
Subject: Pietenpol-List: Pietenpol wingsHello, I'm getting ready to start building, I thought I'd do the wings first. I've got a couple of questions if you don't mind. I have Don Pietenpols plans, are Vi Kapplers better? How did you make your spars, routed plank, I-beametc. Should you build the spars first to get the width dimension of the capsso the ribs can be build to that size? .When you glue the compression struts to the spars did you add any triangle gussets. Thanks for any help!! Vic Harper________________________________________________________________________________
Pietenpol-List: Pietenpol wings
RE: Pietenpol-List: Pietenpol wings
Original Posted By: Victorjeanharper(at)aol.com [mailto:Victorjeanharper(at)aol.com]
Hi Vic,I'll tell you how I did mine--YMMV, as they say. I'm not familiar with ViKappler's wing plans, so I can't speak to that one. I used 1" material formy spars and routed it. I don't feel like I had a particularly good reasonto do it that way, but I liked the idea of having a one-piece machined woodspar. Also, it puts the material at the top and bottom where it does goodand leaves a thinner (1/2") web where it doesn't. I considered, and priced,the I-beam option. It would have been just as good, use less wood, and lotsmore epoxy.I built the ribs with only a single upright next to each rib. It saves aninsignificant amount of weight, and doesn't affect the rib integrity at all.It also makes it impossible to have problems fitting the ribs onto the spar.When I glued up the wing, I used spring clamps to hold the ribs to the sparsas the glue hardened. I made the ribs first--much cheaper, and it gives youa chance to look at the kind of wood that your supplier delivers. I woundup buying my wood from Wick's because of that experiment.I gussetted my compression struts to everything in sight. I didn't trustthe butt joint as far as I could throw it, and I could imagine enoughflexure in the wing to pop the strut off and leave it lying on the bottomsurface of the wing. You can make the top strut flush with the top of thespar and put a plywood gusset over both of them. The bottom strut has to beabove the bottom of the spar due to the undercamber, but I made up atrapazoidal filler block, and gusseted it to the bottom of the spar.Gene HubbardSan Diego-----Original Message-----
Hi Vic,I'll tell you how I did mine--YMMV, as they say. I'm not familiar with ViKappler's wing plans, so I can't speak to that one. I used 1" material formy spars and routed it. I don't feel like I had a particularly good reasonto do it that way, but I liked the idea of having a one-piece machined woodspar. Also, it puts the material at the top and bottom where it does goodand leaves a thinner (1/2") web where it doesn't. I considered, and priced,the I-beam option. It would have been just as good, use less wood, and lotsmore epoxy.I built the ribs with only a single upright next to each rib. It saves aninsignificant amount of weight, and doesn't affect the rib integrity at all.It also makes it impossible to have problems fitting the ribs onto the spar.When I glued up the wing, I used spring clamps to hold the ribs to the sparsas the glue hardened. I made the ribs first--much cheaper, and it gives youa chance to look at the kind of wood that your supplier delivers. I woundup buying my wood from Wick's because of that experiment.I gussetted my compression struts to everything in sight. I didn't trustthe butt joint as far as I could throw it, and I could imagine enoughflexure in the wing to pop the strut off and leave it lying on the bottomsurface of the wing. You can make the top strut flush with the top of thespar and put a plywood gusset over both of them. The bottom strut has to beabove the bottom of the spar due to the undercamber, but I made up atrapazoidal filler block, and gusseted it to the bottom of the spar.Gene HubbardSan Diego-----Original Message-----
Re: Pietenpol-List: Pietenpol wings
Original Posted By: BARNSTMR(at)aol.com
Eugene,Like you, I used the I-beam spar section. But I laminated my spars fromvery fine grade Douglas Fir and installed swallow tail filler blocks at thefitting attachment points. This was back in 1968-69 and Aerolite glue wasthen in favour. On my most recent annual inspection, I found absolutely nosign of glue line separation anywhere, although excess Aerolite fillets thatwere squeezed out during clamping tend to crack and craze. If I were tobuild another wooden airplane, I would use something like T 88.I, too, was leery about those compression struts simply butting up againstthe spar with nothing to hold them in place except the compressive forcegenerated by the drag/antidrag wires. I gusseted everything, as you did,and tied the upper and lower struts together with 1/8" x 1 1/4" plywoodstrips near both front and rear spars. (I had read an account of the com-pression strut on a British SE 5 coming adrift during its testing program.The wing folded and the test pilot was killed. The fix was to secure thecompression strut attachment and the SE 5 became a stout aircraft whichwas about the best available to withstand the rigors of skywriting in theyears following WW I.)My Pietenpol has been flying for nearly 33 years and has given good ser-vice. It is a good design and a few easy, but important, changes can en-hance its durability and safety. I heartily agree with your changes.Cheers,Graham Hansen (CF-AUN, in cooler Alberta, Canada).________________________________________________________________________________
Eugene,Like you, I used the I-beam spar section. But I laminated my spars fromvery fine grade Douglas Fir and installed swallow tail filler blocks at thefitting attachment points. This was back in 1968-69 and Aerolite glue wasthen in favour. On my most recent annual inspection, I found absolutely nosign of glue line separation anywhere, although excess Aerolite fillets thatwere squeezed out during clamping tend to crack and craze. If I were tobuild another wooden airplane, I would use something like T 88.I, too, was leery about those compression struts simply butting up againstthe spar with nothing to hold them in place except the compressive forcegenerated by the drag/antidrag wires. I gusseted everything, as you did,and tied the upper and lower struts together with 1/8" x 1 1/4" plywoodstrips near both front and rear spars. (I had read an account of the com-pression strut on a British SE 5 coming adrift during its testing program.The wing folded and the test pilot was killed. The fix was to secure thecompression strut attachment and the SE 5 became a stout aircraft whichwas about the best available to withstand the rigors of skywriting in theyears following WW I.)My Pietenpol has been flying for nearly 33 years and has given good ser-vice. It is a good design and a few easy, but important, changes can en-hance its durability and safety. I heartily agree with your changes.Cheers,Graham Hansen (CF-AUN, in cooler Alberta, Canada).________________________________________________________________________________