Pietenpol-List: Acceptable tolerances

An archive of the Matronics Pietenpol Listserve.
Locked
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By: "Kringle"
Thanks Curt!Kip G.On Jan 12, 2011, at 12:00 PM, Piet2112 wrote:> > Michael, > > Here are some photos of Kevin Purtee's Fat Bottom Girl that may help. > > Curt Merdan> Flower Mound, TX> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 700#326700> > > > > Attachments: > > http://forums.matronics.com//files/100_1161_113.jpg> http://forums.matronics.com//files/100_1160_203.jpg> http://forums.matronics.com//files/100_1145_100.jpg> > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Acceptable tolerances
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Adjustable Wood Wing Strut Fitting

Post by matronics »

Original Posted By: "DOMIT"
When working with the wood portion of a Pietenpol, what are the acceptable tolerances?I've always heard;Home builder 1/4 inchCabinet maker 1/8Furniture Builder 1/16--------JohnRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Adjustable Wood Wing Strut Fitting
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Post by matronics »

Original Posted By: "Jack Phillips"
I have seen that aircraft in person, and I can absolutely assure you that the picsdo NOT do it justice. It is a beautiful airplane!--------Brad "DOMIT" SmithFirst rule of ground school: This is the ground... don't hit it going fast.Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

RE: Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
All I can tell you is that when I was working on the F-16 Fighting Falcondesign back in the mid '70's, the standard tolerance was +/- .030". Tighttolerances were +/- .010" and required considerable justification. If suchtolerances are good enough for a supersonic jet fighter, they should besufficient for a Pietenpol.Acceptable tolerances are whatever you accept, depending on the materials inquestion. If using T-88, a gap in the joint of up to 1/32" is acceptable.If using Resorcinol, that is unacceptable and will produce a very weakjoint.The tolerance also depends on the measurement in question. For example, inmaking fittings, I would try to make them as accurate as possible and threwsome out that were off by .020" in hole position. But when rigging thewings on my Pietenpol, I got the distance from wingtip to tailpost to bewithin about 1/16" of each other and was delighted to have it that close.Just remember that building an airplane is largely a series of alignmentexercises. The more accurately you make the individual components, theeasier the alignment will be.Jack PhillipsNX899JP "Icarus Plummet"Raleigh, NC-----Original Message-----
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By: KM Heide CPO/FAAOP
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Re: Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By: "Jack Phillips"
Jack, I once (a long time ago) took an aeronautical drafting course and our drafting had to be +/- 0.040 inch. That's a bit closer than most of the Pietenpol drawings.----- Original Message -----
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Acceptable tolerances

Post by matronics »

Original Posted By: brian.e.jardine@l-3com.com
I don't think there can be one general tolerance for everything on the whole project.The fuselage could be plus or minus a half inch (in length or width) and it wouldn'treally make a difference. But if your top cross pieces were 1/8" longeror shorter than the bottom cross pieces, then your fuselage wouldn't be "square",as it needs to be. Similarly, if the rib profile is out by 1/8", it couldpotentially affect the aerodynamics of the wing. On the other hand, if the chordof the wing ended up 1/4" big or small, the difference wouldn't be noticeable.Or if the wingspan was 2" longer than expected, it would likely have no illeffects.The more accurately that the parts are made, the better they will all fit together,and the happier you'll be.More important than dimensional accuracy is dimensional consistency.Additionally, keeping things square (where they are supposed to be square) andsymmetrical is extremely important.Bill C.Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By: "Charles Campbell"
> --> Pietenpol-List message posted> by: "Kringle" > > When working with the wood portion of a Pietenpol, what are> the acceptable tolerances? I've always heard;> > Home builder 1/4 inch> Cabinet maker 1/8> Furniture Builder 1/16> > --------> John> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 719#326719> > > > > > > > Email Forum -> FAQ,> - MATRONICS WEB FORUMS -> List Contribution Web Site -> -Matt> Dralle, List Admin.> > > > ________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> RE: Pietenpol-List: Acceptable tolerances

Post by matronics »

Original Posted By:> owner-pietenpol-list-server(at)matronics.com
> --> Pietenpol-List message posted> by: "Jack Phillips" > > > All I can tell you is that when I was working on the F-16> Fighting Falcon> design back in the mid '70's, the standard tolerance was> +/- .030". Tight> tolerances were +/- .010" and required considerable> justification. If such> tolerances are good enough for a supersonic jet fighter,> they should be> sufficient for a Pietenpol.> > Acceptable tolerances are whatever you accept, depending on> the materials in> question. If using T-88, a gap in the joint of up to> 1/32" is acceptable.> If using Resorcinol, that is unacceptable and will produce> a very weak> joint.> > The tolerance also depends on the measurement in> question. For example, in> making fittings, I would try to make them as accurate as> possible and threw> some out that were off by .020" in hole position. But> when rigging the> wings on my Pietenpol, I got the distance from wingtip to> tailpost to be> within about 1/16" of each other and was delighted to have> it that close.> > Just remember that building an airplane is largely a series> of alignment> exercises. The more accurately you make the> individual components, the> easier the alignment will be.> > Jack Phillips> NX899JP "Icarus Plummet"> Raleigh, NC> > -----Original Message-----
Locked