Pietenpol-List: Spars, Spruce, Fir

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Pietenpol-List: Spars, Spruce, Fir

Post by matronics »

Original Posted By: Jon Christians
I've just about made the decision that I won't purchase 1" spruce stock and then route half of it away. I too am considering 3/4" stock of spruce or douglas fir. I think a box spar would even be better, but I wouldn't know how to calculate the dimensions, although I found the formulas in the wood handbook. 1" box spar would be strong and would have no hidden defects. Any body know of a comparable aircraft that uses box spars? What do Pitts use for spars?A Skywalker II went down nearby due to what looks like a spar failure so I'm looking this area over closely.JoeSpring, TX>From: BARNSTMR(at)aol.com>Date: Wed, 29 Sep 1999 22:34:40 -0400 (EDT)>>Oh...and as for the 2nd part of your question.....Douglas Fir is what I >plan>to use for my spars.... In keeping with the way several other Piet >builders>have done, I am dropping the thickness from 1 inch routed spruce to 3/4 >inch>solid Douglas Fir....I still use the same wing hardware dimensions but use>plywood doublers to fill out to 1 inch in the attach fitting areas. This>also requires use of 1/8th inch shims at each rib (if you are using upright>braces next to the spars)......Terry B________________________________________________________________________________
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Pietenpol-List:

Post by matronics »

Original Posted By: TXTdragger(at)aol.com
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Pietenpol-List: Re: Spars, Spruce, Fir

Post by matronics »

Original Posted By: leonstefanhutks(at)webtv.net (Leon Stefan)
Hey Joe, Whereabouts in Spring do you live? I live in Cypresswood, just off Ella, just moved in the past weekend. I haven't started yet, but as soon as the boxes are empty.....Gary Meadows________________________________________________________________________________
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Pietenpol-List: RE: Spars, Spruce, Fir

Post by matronics »

Original Posted By:> Joe Krzes [SMTP:jkrzes(at)hotmail.com]
A Pitts uses 3/4" Sitka Spruce. I used 3/4" spruce in my spars, routed the rearspars and left the front spars full. BTW, I tried Douglas fir for the aileronspars to keep from having to order more aircraft grade spruce and ended upthrowing them away and remaking them out of spruce. Spruce is lighter and considerablymore pleasant to work with (fir splinters pretty badly). Just my preference.> -----Original Message-----
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> Spars, Spruce, Fir

Post by matronics »

Original Posted By: TXTdragger(at)aol.com
> >> >Oh...and as for the 2nd part of your question.....Douglas Fir is what I > >plan> >to use for my spars.... In keeping with the way several other Piet > >builders> >have done, I am dropping the thickness from 1 inch routed spruce to 3/4 > >inch> >solid Douglas Fir....I still use the same wing hardware dimensions but use> >plywood doublers to fill out to 1 inch in the attach fitting areas. This> >also requires use of 1/8th inch shims at each rib (if you are using upright> >braces next to the spars)......Terry B> ________________________________________________________________________________
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