Brodhead Pietenpol Association

Original Posted By: Dan Yocum
To paraphrase Forest Gump, I'm not a smart man...but I know where to find advicefrom Tony Bingellis...The photo below show my progress attempting to make the center section "U" fitting.I made some progress from A to B to C. Just like the public defender said in the movie "My Cousin Vinnie"... I'm gettingbetter...A is my first attempt without the guidance of Tony.B is my seconds attempt AFTER reading page 48 and 49 of the Yellow Bingellis book.One of the two bends has too little radius.C is a decent fitting needing more polishing of the edges with some 200 grit sandpaper.I'm trying to get all these pieces ready for 'Tools' Toolapalooza 2014 coming upFeb 20-24 in GA. I'm going to see about getting some welding experience onsome scraps of 4130 and if I'm lucky get these fitting done that weekend.--------Bob 'Early Builder' DewenterDayton OHRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/bing ... ______Date: Mon, 10 Feb 2014 08:41:41 -0600

Original Posted By: Dan Yocum

Original Posted By: "DaveG601XL"
In his defense, I spoke on the phone w/Jim just before leaving on a trip. He'sgood people. Just have to understand 'old school'... I've flown w/a lot of guysfrom the Braniff One era. Nothing wrong w/a little writer's turret's. Especiallyafter a few beers after a long haul. It was all meant to be in good fun Iam sure.--------KLNCA65-8N2308CAN HardwareAirframe 724TTW72CK-42 SensenichStandard Factory GN-1Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: More files from the Galacticly inept Piet builder

Original Posted By: "bdewenter"
Bob,My eyeball is certainly no substitute for an accurate measurement, but I struggleto see what is wrong with item B. Assuming this is 4130, it has a bend radiusof 1T. If that is .090 sheet, the bend radius is .090 and a 3/32 bit wouldbe a close radius gage at .09375. It sure looks like more than a 3/32 bitsworth of radius to me. I have more issues with C as it is not a 90 degree bend.How, for example, would you weld two bends made like this together for thecenter section fitting shown on the Piet drawing in the background of your picture?I think you could probably back up to item B and just straighten it upa bit. Now to continue quoting from My Cousin Vinny, my brain is not as smartas a "Craftsman model 1019 Laboratory Edition Signature Series torque wrench.The kind used by Caltech high energy physicists and NASA engineers," so if anyoneelse wants to correct me, go ahead and chime in.Good luck. I just made all the CS fittings last year, but have no handy picturesof them.--------David GallagherZodiac 601 XL-B: flying, 250+ hours nowNext project under construction: Finish my father's AircamperRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: More files from the Galacticly inept Piet builder

Original Posted By: airlion2(at)gmail.com
Careful Dave, I know you. I'll send Russ and Dave over....Glad to see your on the forum. And I'm still hoping for a tech counselor visitfrom you when it warms up this spring.--------Bob 'Early Builder' DewenterDayton OHRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: More files from the Galacticly inept Piet builder

Original Posted By: "Jack Phillips"
Re. Hey bob. I see that you are going to the Chikamauga party on the 21st. I planto go too so I will see you there. GardinerSent from my iPad> On Feb 11, 2014, at 2:51 PM, "bdewenter" wrote:> > > Careful Dave, I know you. I'll send Russ and Dave over....> Glad to see your on the forum. And I'm still hoping for a tech counselor visitfrom you when it warms up this spring.> > --------> Bob 'Early Builder' Dewenter> Dayton OH> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 546#418546> > > > > > > > > > ________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Careful with your math here. A 3/32" drill bit is 0.09375" in DIAMETER.Its radius is half that or 0.046875". If that is a close fit with the bendradius the radius is indeed too tight.Jack PhillipsNX899JPSmith Mountain Lake, Virginia-----Original Message-----

Original Posted By: "bdewenter"
Thanks Jack, I depressed the clutch and disengaged my brain prior to thinking onthat one. 3/16 drill bit.Bob, are you building at New Carlisle or live close by? It would be a short flightfor me. Russ and I could hop on over in the Zenith some weekend.--------David GallagherZodiac 601 XL-B: flying, 250+ hours nowNext project under construction: Finish my father's AircamperRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: More files from the Galacticly inept Piet builder

Original Posted By: "bdewenter"
Jack, I respect your experience. Would you change part C ?--------Bob 'Early Builder' DewenterDayton OHRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: More files from the Galacticly inept Piet builder

Original Posted By: "Jack Phillips"
Jack,I appreciate your experience. Would you change part "C" ?--------Bob 'Early Builder' DewenterDayton OHRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "bdewenter"
Hi Bob,One other suggestion would be to polish the edges prior to bending to remove the stress risers. Polishing after bending only polishes the edges, the stress risers will remain beneath the surface.Greg Cardinal----- Original Message -----

Original Posted By: owner-pietenpol-list-server(at)matronics.com
BobYou didn't ask me but here is my answer. I would not use part C and it isunlikely you could make it the correct size if you tried to fix it. Part Bleft side is your best bend. You might be able to salvage B but it'sprobably not worth the effort. I think you have something wrong with your technique. I found that usingwood forms, like the yellow book shows, for material this thick would crushthe wood and make the bend radius too large and not produce nice bends. Myresults were very similar to your results. Maybe it works with aluminum butI have not tried it. What I ended up doing is taking a piece of 3/8-inch6-inches long x 2-inch wide steel bar (scrap I picked up at a scrap metaldealer). The dimensions don't need to be exact. Make the correct radius onone edge. As others have said 4130 can have a 1xthickness bend radius forthe 90 degree bend. Also, if you're trying for a 90 degree bend you willhave to bend it past 90 so you will have to grind off some of the top of thebar like the book shows. In this picturehttp://westcoastpiet.com/images/Chris%20Tracy/images/IMG_0048.JPG you cansee that I have the part to be bent sandwiched between the radiused bar andanother one that acts as a backer for the fitting (in this case the rudderhorn). You will want to hit the metal to be bent close to the bar so thebend all happens along the bar. I found hitting it with a hammer left marksso I use a chunk of wood or better yet a bronze rod I found at the scrapyard.For the fitting that your trying to make, I made the first 90 bend in thevice like in the picture. Then to form the U I had to clamp it off the endof the vice and use a C-clamp to hold the other end. This will require youto figure out your bend layout (like in the blue Bengals book?) but it isnot hard. What you are striving for are flat side with a nice bend. Notcurved like in the bottom of your part C. If you need any more help I canshoot some better pictures of the process. The best thing I made to bend parts was this.http://westcoastpiet.com/bench-top_bender.htm > It makes for easy bendingand reproducibility.Chris T.Sacramento, CaWestcoastpiet.com-----Original Message-----

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Bob here are a couple of shots from my site showing my makeshift brake.http://www.textors.com/cabane_fittings_010.jpg http://www.textors.com/cabane_fittings_015.jpg http://www.textors.com/Horns_005.jpg Jack TextorWest Des Moines, IA-----Original Message-----

Original Posted By: "bdewenter"
There's a number of things like this in the old Piet. It's commonly said old Bernardknew what he was doing, including the oft referred to "lifting tail" asdemonstrated in so many having down deflection in pictures... but it isn't, atall.So, what we have here, is experimental design, pure and simple. I don't thinkBernard was necessarily a aero genius at all, what he was, was EXTREMELY mechanicallyintuitive. The biggest problem with designs that don't meet the moststringent of genius design, is the question of will it work in the real world,and will if last in the real world.Considering he built however many umpteen of these things, and did it WAY longago, and a bazillion others have as well, we're past the point of being wary ofhis design. If you do it like he did, it'll work. Plain and simple. If youchange it, you'll be in the same position ALL of them guys were back then. I don't think Bernard KNEW his design would work so well, any more than all theother guys who have faded into obscurity knew theirs would fail. It might bebetter, it might be worse!Always great to ask questions, a better understanding never hurts, but part ofthe Piet genre is just hitting the "I believe" button and pressing on... As for specifics, the aileron geometry has always made me wonder. All the slackness,just doesn't look like it'll work or fly well. I LOVE how the thing flies,more than a 757 (which I LOVE to fly...). I just handles really nicely Ithink. After the gear debacle on mine, when I put it all back together the aileroncables were tighter, looked WAY more better to me. Thought that surelythis was gonna be an improvement (the wing moved up a tad due to cabane strutchanges).Wrong. It flew HORRIBLY. Like I have no light civil experience and know somethingis terribly wrong... Landed, made a few calls, confirmed what was kindanagging me and loosened them back to where they were when I got the plane. Flewjust as good as ever. Some combinations just work. I'm not a "Piet purist". However, if you do changefrom the original very much at all, you don't have the same combination, whichtruly makes it experimental! I really don't consider the Piet experimentalin that sense of the word. Bob Denver most likely died because a fuel valve was moved from the design point...Now, did the original designer put it where it was due to some design geniushe had? Probably not... but the change did result in a short guy not beingable to reach it, and had catastrophic results on down the incident chain ofevents. The fact that the original designers position was indeed a really good idea, isnow known. In many designs, this works the other way. Little things crop upover and over and the design is changed (officially or not). As it turns out,Piet's original design really hasn't seen a lot of change. More reliable motors,4130, polyester fabric, more reliable methods of the original motor... butthat's about it.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: More files from the Galacticly inept Piet builder