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Pietenpol-List: Wing Construction

Posted: Mon Dec 02, 2002 2:14 am
by matronics
Original Posted By: "Jack Phillips"
Subject: Pietenpol-List: Wing ConstructionHere is how I built my one piece wing: I used T88 exclusively, and Ace Spar Varnish #16375. The most tedious part, was applying 2 coats of the spar varnish, after ALL construction was 100% complete, getting in every nook & cranny between the gussets, with a small paint brush. I used the 'Single Wrap Spiral' method, as called out in the AC 43-13, to saftey all the turnbuckles. I used torque seal (small squeeze tube of thick laquer paint) on all hardware and fittings, so future inspections through the 10 inspection holes will show any movement. I used Stits Covering method, with 2.7oz on the wing & fuselage, and 1.8oz on the ailerons and empenage. The ribs will now be referred to as 'L1'- Left 1st rib. 'R1' - Right 1st rib. There are 14 ribs on each side. The center rib will be referred to as 'C', and is cut apart to make room for the fiberglass fuel tank. All ribs are identical. Build the rib jig to accept 3/4" spars, and so that the gussets and the upright x next to the spars, are spaced 28 1/16" to 28 1/8" apart. This should be the exact dimention between the spars, with the exception of the 3 center ribs, and the ribs where the lift struts attach. These rib locations have 1/8" plywood doublers on front and aft sides of each spar, and will have to have 1" spar openings. Leave the gussets off in 2 locations of each rib. On the lower forward side of the front spar, and on the aft upper side of the aft spar. Install these gussets after the ribs have been assembled to the spars. This will ensure an easy assembly of the ribs to the spars, and a nice tight fit when it is done. Other gussets to be left off are on the ribs at the inboard aileron station. On this rib (L8 and R8), leave the outboard trailing edge gusset off, for the later installation of the aileron blank plywood (1/16"). I did not cut the ailerons free, untill ALL wing construction was 100% complete, including the aileron spars, braces, hinges, horns, cables & pulleys, and drag / anti-drag cables were installed. After removing the aileron, I removed the fittings, so as to apply varnish underneith, as I did with all fittings. The center section of my wing (forward of the front spar), is designed so as to allow the top of the radiator tank to be within the wing, behind the leading edge. Two 1/8" plywood L.E. ribs, are spaced evenly between, and paralell to, R1 and L1. These sub ribs will accept the 1/16" plywood L.E. (on top), and the 1/32" plywood (within the radiator cavity). The radiator was custom made, to be the width between the cabane struts, and I have forward view below the radiator. Plans type, barn door hinges are numbered 1 thru 6, beginning on the left wing tip. The aileron gap was sealed with a piece of 2" fabric tape, before paint was applied. I also made sealed gap hinges on the empenage, but used a different method, due to the Vi Kapler hinges, that pivot at the center. I have pictures of this scanned in, if anyone is interested. Lots of places on the wing needed to be drilled using Granpap's hand crank drill (chordless !!), because of clearance reasons. Cable guide blocks were numbered 1 thru 8, starting at the top left. I glued 1/4" plywood to the spar, then screwed the guide blocks to the plywood, so as not to drill any extra holes in the spars. Jury strut C/L is 37" outboard of C/L of cabane strut attachments. I estimated the placement of the jury strut attachments by referring to the picture of the Pietenpol on the 1999 I A M Union Calender. The 1/8" Plywood doublers, located at the center section and the lift strut attachments, should have Spaded Ends (football shaped). These doublers bring the width of the spar to the plans width of 1", and allow the plans dimentions to be used for all the fittings. These 5 ribs must be made to accept 1" spars. The ribs were weighted, without varnish, and the heaviest ones were installed inboard, progressively installing the lighter ones toward the wingips. The two inboard ribs are the only ones that are made out of Spruce, the rest of the ribs are made out of Western Cedar. LEFT SIDE RIGHT SIDE 1.) 7.24 oz Spruce 1.) 7.4 oz Spruce 2.) 7.8 oz All other ribs are Cedar 2.) 7.96 oz All other ribs are Cedar 3.) 7.91 oz 3.) 7.93 oz 4.) 7.5 oz 4.) 7.91 oz 5.) 6.58 oz 5.) 6.56 oz 6.) 7.94 oz 6.) 6.34 oz 7.) 6.4 oz 7.) 6.44 oz 8.) 7.93 oz 8.) 6.4 oz 9.) 6.44 oz 9.) 6.3 oz 10.) 6.34 oz 10.) 6.25 oz 11.) 6.29 oz 11.) 6.2 oz 12.) 6.22 oz 12.) 6.17 oz 13.) 6.15 oz 13.) 6.14 oz 14.) 6.1 oz 14.) 6.09 ozChuck GantzerNX770CGp.s. I'm re-powering my plane with a Continental A65 engine. ________________________________________________________________________________

Pietenpol-List: Wing Construction

Posted: Sun Jun 26, 2005 12:16 am
by matronics
Original Posted By: "M&M Stanley"
What kind of fixture is most often used to build the wings on. Do I need a solidtable or would a couple of good saw horses supporting the spars work (One oneach end and one or two in the middle)Chris TracySacramento, Ca________________________________________________________________________________

Re: Pietenpol-List: Wing Construction

Posted: Sun Jun 26, 2005 8:29 pm
by matronics
Original Posted By: Catdesign
ChrisIf you are building a 3 piece wing, a couple of saw horses is just fine. However,for a 1 piece wing you may want something more stable. I built a rotatingtable that would carry the entire wing and I could flip it to work on the topor bottom. Dick N. ----- Original Message -----

Re: Pietenpol-List: Wing Construction

Posted: Sun Jun 26, 2005 11:55 pm
by matronics
Original Posted By: "Peter W Johnson"
Subject: Re: Pietenpol-List: Wing ConstructionIn a message dated 6/26/2005 12:18:13 AM Central Standard Time, catdesign(at)intergate.com writes:What kind of fixture is most often used to build the wings on. Do I need a solid table or would a couple of good saw horses supporting the spars work (Oneon each end and one or two in the middle)Chris TracySacramento, CaChris,I built my one piece wing in my house. Made for quite a conversation piece !! It went down through the living room, dining room, and out the back door into the enclosed in back porch. I made a jig to support the wing in a verticalattitude, leading edge down, to about 6" off the floor. Initially, the 4 jigs (made from 1 X 4's) supported the wing by the spars, with two vertical pieces and two cross pieces that the spars rested on, while I slid the ribs on.Squared & straightened everything up, and glued the ribs on, finished the ailerons, hardware, and rigging. Then I made 4 other jigs to support the wingby the hard points at the cabane struts and lift struts. This allowed me to do allthe fabric and paint work. It worked out very well because I had access to the top and bottom of the wing, working in a climate controlled environment...air-condition in the summer and heat in the winter. It took me ayear to build and complete it, working on it as much as I could, every single day. The wing was 100 % complete, when we carried it out the front door, and built a jigon the trailer to haul it to the airport. That day was one of those milestones!!Chuck G.Flew for an hour this evening in gusty wind, but down the runway.________________________________________________________________________________

Re: Pietenpol-List: Wing Construction

Posted: Mon Jun 27, 2005 12:16 am
by matronics
Original Posted By: "Christian Bobka"
Subject: Re: Pietenpol-List: Wing ConstructionI am building a 3 piece wing and a couple of saw horses worked fine. A3rd. saw horse was used to support the center section. I built my wingoff of the center section so that I would know that it was going to boltup . Leon S.________________________________________________________________________________

Pietenpol-List: Wing Construction

Posted: Thu Jan 27, 2011 5:28 pm
by matronics
Original Posted By: "cjborsuk"
I got an elevator door skin that is brand new. It has a tiny ding on one end isthe reason I got it. It is just the right width with 90 degree flanges....alreadyhalf made. I need to take a support out of it that is glued in. The glueis gray colored and not rock hard but yet it is not rubbery. How do I get theglue to turn loose without harming that mirror finish? Heat?? I tried a heat gunand it didn't put out enough heat.--------Jerry Dotson59 Daniel Johnson RdBaker, FL 32531Started building NX510JD July, 2009wing, tailfeathers done, fuselage rollingusing Lycoming O-235Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Wing Construction

Pietenpol-List: Re: Wing Construction

Posted: Thu Jan 27, 2011 5:49 pm
by matronics
Original Posted By: "K5YAC"
http://www.youtube.com/watch?v=_6byakUa ... aleighRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Wing Construction

Pietenpol-List: Re: Wing Construction

Posted: Thu Jan 27, 2011 5:58 pm
by matronics
Original Posted By: "bender"
Nice... very exciting when all those ribs start to look like a wing.--------Mark ChouinardWings, Center Section and Empannage framed up - Working on FuselageRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Wing Construction

Re: Pietenpol-List: Wing Construction

Posted: Thu Jan 27, 2011 8:45 pm
by matronics
Original Posted By: "cjborsuk"
Very nice, Chuck.Tell us a little about your spars. What material did you use for the web and flanges? What are the dimensions?Thanks,Greg CardinalMinneapolis----- Original Message -----

RE: Pietenpol-List: Wing Construction

Posted: Thu Jan 27, 2011 9:01 pm
by matronics
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Looking good, Chuck.Jack PhillipsNX899JP "Icarus Plummet"Raleigh, NC-----Original Message-----

Pietenpol-List: Re: Wing Construction

Posted: Thu Jan 27, 2011 9:15 pm
by matronics
Original Posted By: "cjborsuk"
I used a combination of quarter-inch and three-eighth marine ply, doug fir andspruce. I cut the 3/8 ply to width and scarfed two pieces together. After a lotof trial and error on getting the scarf joints to work, I came up with a solutionusing my table saw. I am very pleased with the result. I can go into moredetail on how I did this if needed. I then ripped the doug fir for the top andbottom of the spars and scarfed those together. I used the quarter-inch plyto fill in the middle and end of the spars. I had some left over spruce thatI planed down for the tips. Results: Time: This method takes much longer than using solid spruce and routing out thespars. Money: I saved a bunch of money. I figure I spent about $300 total for all thematerial. I was able to buy the marine ply and doug fir local. Weight: Based on what I have been able to determine using info in the forum, theyweigh slightly less than the routed spruce spars. Strength: I am sure this could be debated, but I think they are stronger than thespruce. As stated many times in this forum, I find that working with spruce is much moreenjoyable than working with the doug fir. Spruce is just a joy to work with.With the doug fir plan on many splinters. All my ribs are spruce and I did notget the first splinter. Overall, I am very pleased with the way the spars turned out. Dimensions: Approx 5 inches tall (front spar a bit taller than the aft). 7/8 onthe width.ChuckRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Wing Construction

Pietenpol-List: Re: Wing Construction

Posted: Fri Jan 28, 2011 6:00 am
by matronics
Original Posted By: "Dangerous Dave"
WOW! All of your answers were exactly what I needed to get me going, thanks!Douwe________________________________________________________________________________Subject: Pietenpol-List: Re: Wing Construction

Posted: Fri Jan 28, 2011 6:54 am
by matronics
Original Posted By: "Charles Campbell"
Chuck,beauty job.Keep up the good work.dave--------Covering PietRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Re: Pietenpol-List: Re: Wing Construction

Posted: Fri Jan 28, 2011 7:48 am
by matronics
Original Posted By: "cjborsuk"
Yes, I have a couple of questions. I have been planning to use solid 3/4-inch boards for my spars. A few pics on the forum, including yours, have sort of gotten me thinking about built-up spars. First, where did you find 3/8-inch thick plywood, and how did you scarf the plywood pieces on a table saw? You asked for it! :>) Chuck C, Winston-Salem, NC----- Original Message -----

Pietenpol-List: Re: Wing Construction

Posted: Sat Jan 29, 2011 12:11 pm
by matronics
Original Posted By: "bender"
my engine is at Antique Engine Rebuilders now....i talked to the owner who hasbuilt a ton of A engines about what we do with the engine..a high compression head seems to give the most bang for the buck and fuel and airare big too. my engine will have bigger intake valves modern chevy pistons,lighter and better ring seal.. a reground B profile cam that has a bit more liftand duration from what i understand. we talked about a new "340" cam... buthe seemed to think that at 2000 rpm it may not be enough worth the $500 forthe cam... he says spend the money on a good head and intake and carb. the B carbis bigger than the A but the A intake could be opened up to match the B bore.i plan to build my own intake... we'll see how it goesBTW snyders is working on a new casting for their 8 plug aluminum head... i'm onthe list for one when they come outjeffRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Wing Construction

Pietenpol-List: Re: Wing Construction

Posted: Tue Feb 01, 2011 2:56 pm
by matronics
Original Posted By: "Mild Bill"
I never added up the cost of the raw materials, my guess is around $ 15KHowever consider this:Flying an airplane build by your own hands,...pricelessThat first flight is the most expensive (cost per hour) but worth every penny.HansNX15KVlong fuse, 3 piece wing, Corvair powered________________________________________________________________________________Subject: Pietenpol-List: Re: Wing Construction

Posted: Tue Feb 01, 2011 3:17 pm
by matronics
Original Posted By: Ben Charvet
DOMIT wrote:> Hmmm... not to be the "bad guy" here... looks very nice! But.. is your plywoodweb done with the face grain running along the length of the spar? "Best practice"is 45 degrees, but vertical face grains are stronger than horizontal.(Ok, you can tell me to shut up now...) > > The web carries loads in shear... essentially parallel to the length of the spar.This means the loads are trying to split the face grains of the ply if itis oriented parallel to the length.> > I'd test this carefully- from the sizes you listed it is probaby plenty stout,but just to be safe! Did the design call for ply running parallel to the length?If so, someone probably did all the calculations and said it is ok. Ifnot, I'd verify it before flying it.> > Once again, my apologies for the somewhat-negative comments. I'm not tryingto be the bad guy, just trying to say "be safe!"As written in the Scriptures (specifically, NACA Technical Report No. 344, TheDesign of Plywood Webs for Airplane Wing Beams):"A study of the results of shearing tests and static tests of beams leads to theconclusion that plywood webs are most efficient when the grain of one ply isat 90 to the grain in adjacent plies, when the web is so arranged that the grainof half of the materials is at 90 to the grain of the other half, and whenthe grain of all the plies is at 45 to the longitudinal axis of the beam."...."Allowable shear stresses for plywood webs so constructed that the plies are alternatelyparallel and perpendicular to the length of the beam should not exceed87 1/2 per cent of those recommended for 45 plywood. The beams with 45 plywoodwebs are also stiffer than the others, because of the fact that the shearingmodulus for the 45 webs is higher than for the parallel-perpendicular webs."...."Very few data are available relative to the shearing modulus of plywood webs thegrain of which is alternately parallel and perpendicular to the length of thebeam. What data are available indicate that the shearing modulus of such plywoodis the same as that for solid wood of the same species. In other words,the shearing modulus of 45 plywood is about three times as great as that for parallel-perpendicularplywood."http://naca.central.cranfield.ac.uk/rep ... rt-344.pdf(Note the UK domain - the Brits' pdf copy of this report is a lot better than NASA's.)The question is how a 3/8" thick parallel-perpendicular plywood web on a PietenpolI-beam spar fits in with all this. I would have to find my copy of ANC-18and other reference materials and crunch some numbers before venturing an opinionone way or the other. (But I suspect that 3/8" is overkill and there's noneed to worry about the grain orientation on the spar that has already been built.)--------Bill FrankRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Tue, 01 Feb 2011 16:41:19 -0500

Re: Pietenpol-List: Re: Wing Construction

Posted: Tue Feb 01, 2011 5:47 pm
by matronics
Original Posted By: "Mild Bill"
NACA Technical Report #344, ANC-18, part of ANC-19 and other good info on built-up spars is available on Chris Tracy's website www.westcoastpiet.comGreg Cardinal----- Original Message -----