Pietenpol-List: Rib Lofting

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matronics
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Pietenpol-List: Rib Lofting

Post by matronics »

Original Posted By: jmcnarry(at)techplus.com (John McNarry)
Subject: Pietenpol-List: Rib Lofting>I got to looking at the rib layout tonight. I had a copy of>jpg's from Richard DeCosta's site that showed his ribs. As>I looked at them I noticed that there were spar nailer uprights>in his ribs that are not on the BHP plans. The spar uprights>are on the rib template that I got with the plans. I was>going to loft the rib onto the jig to avoid the errors in the>paper template. It is off by 1/8" between the spars. This>got me wondering - a very dangerous thing.>>Are there any other differences in the airfoil shown on the>plans and the template?>>Should I add the uprights at the spars?>>Is the 1/8" error in the distance between the spars anything>to worry about?>>Does any of this matter? Should I just 3M77 the template to>a piece of plywood, varnish it, and have at it to make the>rib jig?>>Dave>>________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Rib Lofting

Post by matronics »

Original Posted By: "alan.green"
I got to looking at the rib layout tonight. I had a copy ofjpg's from Richard DeCosta's site that showed his ribs. AsI looked at them I noticed that there were spar nailer uprightsin his ribs that are not on the BHP plans. The spar uprights are on the rib template that I got with the plans. I wasgoing to loft the rib onto the jig to avoid the errors in thepaper template. It is off by 1/8" between the spars. Thisgot me wondering - a very dangerous thing.Are there any other differences in the airfoil shown on theplans and the template?Should I add the uprights at the spars?Is the 1/8" error in the distance between the spars anythingto worry about?Does any of this matter? Should I just 3M77 the template to a piece of plywood, varnish it, and have at it to make therib jig?Dave________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Rib Lofting

Post by matronics »

Original Posted By: Dave and Connie
Dave; Ref the upright spar nailers in the ribs, those make attaching the ribs tothe spars much easier and will make all the ribs contact the spars at thesame uniform place on the ribs. The original method was to insert thoselittle wedges under the capstrips for attachment to the spar. The uprights,to me, are just all around more precise and make assembly simpler...... .....gotta think about the 1/8" error, haven't ran into that before.Earl Myers-----Original Message-----
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