Has anyone done any stress analysis on the outer main spar built to the
dimension on the early plans that showed the outer end at 5 ½ instead of 5 ¼ .
When trimmed down to the wing tip airfoil thickness the spar cap height is 7/16?
on top and bottom. I have found this to be the case with my spars. They were
built to plans purchased in 1978. I stopped to have kids and raise them. I know
that there were many built that way. Rick Lanning?s N4DD unless the wings have
been changed. There was no mention of that dimension change in the early KR
newsletters however I have an early plan set and a revised set purchased in
1988. and a beautifully fabricated set of outer spars that are 5 ½? at the outer
end. Aprox. $400 to rebuild. Any suggestions. The spar caps are the most
expensive component. I could likely cut them out and set up a shave cut on the
table saw of 1/32? on three sides and rebuilt them using 1/8? plywood webs to
make up the width difference with no strength degredation at all. But that?s a
lot of extra work.
