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Spar Butt Fittings

John Burnett

Well-Known Member
Oct 8, 2006
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I am having difficulty making the butt fittings work as drawn.

The problem is the location of the holes that the Drag Wire

Lug will attach to.

I am thinking that I want one of the lugs above the centerline of

the spar and the other below the centerline of the spar (the same

distance that I have with my drag blocks.

When I lay it out both holes are below the centerline of the spar. The

rear spar by a distance of .098 and the front spar by a distance of

.183 inches, I'm using a CAD system.

If I use this layout I am sure to get interference on the 1/4 in wires

because I will be bolting into spar holes and drag blocks that are

located .160 inches above and .160 inches below the centerline of the spar.

I have a pdf file that I will try to attach to this message. I also have

a dwg or dxf file that I could email someone with a CAD system to

see if I am missing something.

I haven't found anything in the print errata and I am having a hard

time believing that I am the first to catch this.


John Burnett



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