Original Posted By: "kevinpurtee"
Kevin, despite your problems, youre having better luck with Mark P. than I am.I handed him my heads at corvair college 20 in Hinsdale, MI on June 4 of lastyear. Not a word from him since. He hasnt returned my calls to his business,cell phone and email. Dont know if I will ever see my heads again.--------JohnRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Destructive Testing of Wooden Lift Struts
Pietenpol-List: Destructive Testing of Wooden Lift Struts
Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: "K5YAC"
I mentioned a few months ago that my original wood struts were delaminating. TheSainted Gary Boothe made me new ones which are going strong and look great.Anyway, as I was moving to a new hangar a couple of months ago I needed to getrid of the old struts. They would fit in the dumpster better if I broke themin two. Destructive Test 1): I put one end of a strut on the u-haul bumper and the otherend on the ground. I attempted to stomp in the middle of the strut to get itto break. The only thing that came close to being broken was my ankle. Itwouldve taken a lot more than my 200 pounds stomping on that strut to get it tofail.Destructive Test 2): Cut same strut half way through and repeated Test 1. Again,the only thing close to breaking was my ankle.Destructive Test 3): Cut same strut until less then was left intact and repeatedTest 1. This time, after several stomps and much protest, the strut gave way.Destructive Test 4): Having determined that the only way to destroy the strutswas to cut them up, I took the opportunity to inspect the delaminating portions.Turns out, the delaminations went in about 1/8 and the rest of the glue jointswere intact.I've mentioned this before: the fitting attach bolt holes at the ends of the strutsshowed no signs of distress.Not exactly scientific, but it's real. The struts had ~260 hours and several hundredlandings on them. For what its worth.--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
I mentioned a few months ago that my original wood struts were delaminating. TheSainted Gary Boothe made me new ones which are going strong and look great.Anyway, as I was moving to a new hangar a couple of months ago I needed to getrid of the old struts. They would fit in the dumpster better if I broke themin two. Destructive Test 1): I put one end of a strut on the u-haul bumper and the otherend on the ground. I attempted to stomp in the middle of the strut to get itto break. The only thing that came close to being broken was my ankle. Itwouldve taken a lot more than my 200 pounds stomping on that strut to get it tofail.Destructive Test 2): Cut same strut half way through and repeated Test 1. Again,the only thing close to breaking was my ankle.Destructive Test 3): Cut same strut until less then was left intact and repeatedTest 1. This time, after several stomps and much protest, the strut gave way.Destructive Test 4): Having determined that the only way to destroy the strutswas to cut them up, I took the opportunity to inspect the delaminating portions.Turns out, the delaminations went in about 1/8 and the rest of the glue jointswere intact.I've mentioned this before: the fitting attach bolt holes at the ends of the strutsshowed no signs of distress.Not exactly scientific, but it's real. The struts had ~260 hours and several hundredlandings on them. For what its worth.--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Pietenpol-List: Re: Pietenpol International Relations
Original Posted By: "K5YAC"
That's more testing than I've done. Thanks for sharing the details.--------Mark ChouinardWings, Center Section and Empannage and Fuse framed up - Working on Landing GearRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Pietenpol International Relations
That's more testing than I've done. Thanks for sharing the details.--------Mark ChouinardWings, Center Section and Empannage and Fuse framed up - Working on Landing GearRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Pietenpol International Relations
Original Posted By: "TOM STINEMETZE"
Awesome! That's good stuff.--------Mark ChouinardWings, Center Section and Empannage and Fuse framed up - Working on Landing GearRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 10 May 2012 13:41:49 -0500
Awesome! That's good stuff.--------Mark ChouinardWings, Center Section and Empannage and Fuse framed up - Working on Landing GearRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 10 May 2012 13:41:49 -0500
Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: "tools"
Scotty I too shied away from heating metal before working. Its actually easy andworks better that way. If you squish it in a vise make sure the jaws are smoothor covered with smooth metal. Experiment with some scrap heating till red,it doesn't take that much heat.Jack TextorSent from my iPadOn May 10, 2012, at 4:04 PM, "bubbleboy" wrote:> > Thank you everyone for your comments. If I was to use tube and squash each end,do I need to heat the ends first and squash them while hot? Metal work is notmy comfort zone so im treading very carefully here and want to get it right.> > Scotty> > --------> Tamworth, Australia> Building a Corvair Powered Pietenpol Air Camper> > www.scottyspietenpol.com> > Rudder, Vert stab, Elevators, Hor Stab and Ribs built...About to start fuselage...Corvairengine at Roy's Garage waiting to be modified.> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 774#372774> > > > > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Scotty I too shied away from heating metal before working. Its actually easy andworks better that way. If you squish it in a vise make sure the jaws are smoothor covered with smooth metal. Experiment with some scrap heating till red,it doesn't take that much heat.Jack TextorSent from my iPadOn May 10, 2012, at 4:04 PM, "bubbleboy" wrote:> > Thank you everyone for your comments. If I was to use tube and squash each end,do I need to heat the ends first and squash them while hot? Metal work is notmy comfort zone so im treading very carefully here and want to get it right.> > Scotty> > --------> Tamworth, Australia> Building a Corvair Powered Pietenpol Air Camper> > www.scottyspietenpol.com> > Rudder, Vert stab, Elevators, Hor Stab and Ribs built...About to start fuselage...Corvairengine at Roy's Garage waiting to be modified.> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 774#372774> > > > > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: shad bell
Hey Kevin (or Gary),Could you post some detailed pics of the end fittings? I'm sure I took some lastBrodhead, but I can't for the life of me find where I downloaded them...Thanks!Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 10 May 2012 15:55:33 -0700 (PDT)
Hey Kevin (or Gary),Could you post some detailed pics of the end fittings? I'm sure I took some lastBrodhead, but I can't for the life of me find where I downloaded them...Thanks!Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 10 May 2012 15:55:33 -0700 (PDT)
RE: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Kevin - Take a knee, buddy...I got this...Tools,Pictured is Kevin's forward and rearward upper mountings (picture on theleft with his old struts, on the right with the new). He chose to givehimself some adjustment (on the rear strut?). I'm way too simple tounderstand wash-in / wash-out (Kevin, being a fling-wing pilot, understandsall that complicated stuff like blade precession, etc.), so I will beemploying the attachment on the left, for all 16 points. I noticed some timeback that Douwe had set his up that way, and when I asked him how to makeadjustments, he said he couldn't.just measure carefully. I decided that, ifI could build an airplane, I could measure carefully.St. GaryNX308MB-----Original Message-----
Kevin - Take a knee, buddy...I got this...Tools,Pictured is Kevin's forward and rearward upper mountings (picture on theleft with his old struts, on the right with the new). He chose to givehimself some adjustment (on the rear strut?). I'm way too simple tounderstand wash-in / wash-out (Kevin, being a fling-wing pilot, understandsall that complicated stuff like blade precession, etc.), so I will beemploying the attachment on the left, for all 16 points. I noticed some timeback that Douwe had set his up that way, and when I asked him how to makeadjustments, he said he couldn't.just measure carefully. I decided that, ifI could build an airplane, I could measure carefully.St. GaryNX308MB-----Original Message-----
Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: "Gary Boothe"
Wow, simple enough. Are those AN4's or one size larger? Are they lined up, orstaggered a bit (can't quite tell by the photo, look lined up with each other)?What's the spacing (can probably come close with a educated guess, but ifyou have it handy...)? Lastly, insofar as "measuring carefully, no washout or anything, right? Just maintainthe same incidence set by lift struts? Thanks again! Crazy quick, really appreciate that.Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Wow, simple enough. Are those AN4's or one size larger? Are they lined up, orstaggered a bit (can't quite tell by the photo, look lined up with each other)?What's the spacing (can probably come close with a educated guess, but ifyou have it handy...)? Lastly, insofar as "measuring carefully, no washout or anything, right? Just maintainthe same incidence set by lift struts? Thanks again! Crazy quick, really appreciate that.Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
RE: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Kevin will have to answer for his. Mine are AN3, with an AN5 bracket-to-wingattach. Brackets are about 6" long, with AN3's unevenly spaced from 1 1/2"to 2", in a straight line.....AND NOT FLIGHT TESTED!Gary BootheNX308MB-----Original Message-----
Kevin will have to answer for his. Mine are AN3, with an AN5 bracket-to-wingattach. Brackets are about 6" long, with AN3's unevenly spaced from 1 1/2"to 2", in a straight line.....AND NOT FLIGHT TESTED!Gary BootheNX308MB-----Original Message-----
Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: "kevinpurtee"
@Shad: Both failures showed themselves very quickly when the little chunk of valvephysically broke off and apparently left through the exhaust pipe. It lost100 rpm and the engine ran a little rougher. Looking forward to the big words:).--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
@Shad: Both failures showed themselves very quickly when the little chunk of valvephysically broke off and apparently left through the exhaust pipe. It lost100 rpm and the engine ran a little rougher. Looking forward to the big words:).--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Destructive Testing of Wooden Lift Struts
Original Posted By: shad bell
Thanks, Gary:).@Mike: the bolts bolting the fittings to the struts are AN4 and the bolts boltingthe fittings to the wings are AN5 or 6. If the bolt holes on the fitting arestaggered it's because I couldn't drill the holes in a straight line. I have used the threaded adjustment feature on the two aft fittings to make theairplane fly straighter. It would certainly be flyable without the adjustmentbut I'm glad I have the ability to tweak it. Gentle, hardly-noticeable turnsare fine in the traffic pattern. They get tedious on cross country flights.A general thought for builders considering wood struts: if you're worried aboutthe design considerations associated with wood struts then you may want to keepit simple and build to the plans. Can't go wrong doing that.--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 11 May 2012 00:23:09 -0700 (PDT)
Thanks, Gary:).@Mike: the bolts bolting the fittings to the struts are AN4 and the bolts boltingthe fittings to the wings are AN5 or 6. If the bolt holes on the fitting arestaggered it's because I couldn't drill the holes in a straight line. I have used the threaded adjustment feature on the two aft fittings to make theairplane fly straighter. It would certainly be flyable without the adjustmentbut I'm glad I have the ability to tweak it. Gentle, hardly-noticeable turnsare fine in the traffic pattern. They get tedious on cross country flights.A general thought for builders considering wood struts: if you're worried aboutthe design considerations associated with wood struts then you may want to keepit simple and build to the plans. Can't go wrong doing that.--------Kevin "Axel" PurteeNX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 11 May 2012 00:23:09 -0700 (PDT)