Brodhead Pietenpol Association

Original Posted By: Mike Townsley
Wings coming down from attic next..________________________________________________________________________________Date: Wed, 17 Mar 2010 07:51:55 +0800

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Looks great! Finally coming out of the closet, huh?Jack PhillipsNX899JPRaleigh, NC-----Original Message-----

Original Posted By: Michael Perez

Original Posted By: "coxwelljon"
Guys,If you build cabane length to the CAD or previous plans you will end up with zeroor minus angle of incidence (from mean cord line). The plane will fly taillow (as reported) with added trim drag and you won't be able to touch down atstall speed with out hitting the tail wheel first. I physically measured theangle of my center section to confirm 1.5 degree a.o.i. with the aft struts 1"shorter.Tom BernieGloucester MassN666TBOn Mar 18, 2010, at 6:28 AM, skellytown flyer wrote:> > Jon I expect you will get many answers on that.I like you bought my project andthe cabanes were done. I believe DJ made them both longer to help with entryand with more angle of attack to help the fuselage fly more level since he thoughtmany of the planes flew in a tail low attitude.naturally it flies withthe wing at the right angle to provide the needed lift and your fuselage angleis determined by that. so he reasoned that having slightly longer front cabaneswould level the fuse in flight.at least that's what I remember him tellingme.does that make sense or help? I'm currently trying to finish up the cowlingso I can start final assembly. Where are you located?Raymond. Texas panhandle> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 729#290729> > > > > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: GN-1 cabane length

Original Posted By: "coxwelljon"
skellytown flyer wrote:> Jon I expect you will get many answers on that.I like you bought my project andthe cabanes were done. I believe DJ made them both longer to help with entryand with more angle of attack to help the fuselage fly more level since he thoughtmany of the planes flew in a tail low attitude.naturally it flies withthe wing at the right angle to provide the needed lift and your fuselage angleis determined by that. so he reasoned that having slightly longer front cabaneswould level the fuse in flight.at least that's what I remember him tellingme.does that make sense or help? I'm currently trying to finish up the cowlingso I can start final assembly. Where are you located?Raymond. Texas panhandleRaymond,I am located in upstate NY, just north of Utica NY just inside the Adirondack Park.I think I have read somewhere that one needs approx. 2 deg. of incidence.between the chord line and the line of horizontal thrust. The horizontal lineof thrust is easy as it parallels the top longeron. The Chord line is moredifficult. My understanding is that it runs from the trailing edge to the centerof the radius on the leading edge. I had thought that a line through thecenterline of the spars would parallel the chord line but this is not true onthe GN-1 I am not sure about the Piet as its airfoil has a little bit sharperleading edge.--------Jon Coxwell GN-1 BuilderRecycle and preserve the planetRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: GN-1 cabane length

Original Posted By: "Richard Schreiber"
Tom Bernie wrote:> Guys,> If you build cabane length to the CAD or previous plans you will end up withzero or minus angle of incidence (from mean cord line). The plane will fly taillow (as reported) with added trim drag and you won't be able to touch downat stall speed with out hitting the tail wheel first. I physically measured theangle of my center section to confirm 1.5 degree a.o.i. with the aft struts1" shorter.> Tom Bernie> Gloucester Mass> N666TB> > On Mar 18, 2010, at 6:28 AM, skellytown flyer wrote:> > > > > > > > Jon I expect you will get many answers on that.I like you bought my projectand the cabanes were done. I believe DJ made them both longer to help with entryand with more angle of attack to help the fuselage fly more level since hethought many of the planes flew in a tail low attitude.naturally it flies withthe wing at the right angle to provide the needed lift and your fuselage angleis determined by that. so he reasoned that having slightly longer front cabaneswould level the fuse in flight.at least that's what I remember him tellingme.does that make sense or help? I'm currently trying to finish up the cowlingso I can start final assembly. Where are you located?Raymond. Texas panhandle> > > > > > > > > > Read this topic online here:> > > > http://forums.matronics.com/viewtopic.p ... 729#290729> > > > > > Tom,> > > > My plans are the hand drawn plans with a copyright date of 1992 and on sheet6 it shows the cabanes with a dimension of what appears to be 21" and an editreferring to page 7. I am not sure if the edit was part of the plans or doneby my planes original builder. On Page 7 it calls out the cabanes as 21" frontand 21 3/4" rear. My cabanes are 23 1/2" for all 4.> > If my calculations from my own personal CAD layout of the airfoil are correctthen I now have 1.71 degrees of incidence. ( will strike a chord line on mycenter section to verify with my drawing) If your GN-1 has them 1" shorter thenit would seem like there is quite a bit more incidence, all things being equal.I need to measure more.> > > > Thanks for the input.> > > > > > > > > > > > > > > > > > > --------Jon Coxwell GN-1 BuilderRecycle and preserve the planetRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "coxwelljon"
Good People,I was wondering about what alloy to use for my aluminum Pitot tubes. I have some1/4 inch 3003 - .035", but that seems too easy to bend. I was thinking about6061T6, but was concerned about how easy it would be to put in the 90 deg bendseven with using a tubing bender and packing the tube with sand. Does anyhave any experience with 6061 or 5052? Those that made your own pitot tubes, whatdid you use and how have they held up to the casual knock and bump?I off in a few minutes to see a friends corvair project for his piet. Its goingto be in the 60's here in Indiana and in the 70' tomorrow - with snow this weekend.Rick Schreiber,Valparaios, InRichard Schreiberlmforge(at)earthlink.netWhy Wait? Move to EarthLink.________________________________________________________________________________Subject: Pietenpol-List: Re: GN-1 cabane length

Original Posted By: "walt"
OK, I did my measuring. I did a little more looking on the web and found thatthe recommended angle of incidence for the Pietenpol wing is 3 degrees. I amassuming it is the same for the GN-1 wing. From posts I read this allows forsome washout on the tips. As I remember from Broadhead this summer the washoutmakes the Piet a much better flying bird.I struck a chalk line from the trailing edge to the center of the curve on theleading edge to get the chord line. The chord line is at an angle of 1.83 degreesto a line through the center of the mounting holes for the cabane struts.To get to the recommended 3 degrees I will need to lengthen my front cabanesby 5/8" to get 3 degrees. Probably the easiest is to weld another tube for theattach bolt on top of the existing attach point and a new saddle strap overthe top. The fix will be tell tale at any gatherings but then I am not buildinga show plane and it seems like a lot less work than cutting the strut andlengthening it.Thanks for your comments--------Jon Coxwell GN-1 BuilderRecycle and preserve the planetRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: Richard Schreiber
testwalt evansNX140DL ----- Original Message -----