Quote:
Originally Posted by Dogtail2
Joe
Looks to me that unless the spar is rotated, the cut out will get way too close to the bottom of the rib. (red spar bottom rear edge). Rotating leaves 'meat' top and bottom.
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And that is what's causing me a fit! It would seem that I should not allow that oddball cut-out but, yet there is the discrepancy between the cut-out angle on the drawing and the spar section detail with respect to it's position (90 deg face to "C" plane).
So far, I can "confirm" that I cannot change the dimensions of the spar as per the below passage from the AC 43.13-1B
Quote:
1-41. SPAR REPLACEMENT. Owner-produced
spars may be installed providing they are made
from a manufacturer-approved drawing. Also,
a spar may be made by reference to an existing
spar providing sufficient evidence is presented
to verify that the existing spar is an original
part, and that all materials and dimensions can
be determined. The dimensions and type of
wood used are critical to the structural strength
of the aircraft. Care should be taken that any
replacement spars accurately match the manufacturer’s
original design.
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So this eludes to precisely as you point out, rotation of the spar to the 4 degrees. Still, not quite a good fit between the spar caps.
Questions to be answered then.
1) Rib profile re-check?
2) Can I "trim" into the end caps to fit the spar if my rib profile checks out ok?
2) Grain orientation
3) Pup & Strutter comparison?
Thanks for the input!