Brief Description: Screen grabs of discarded tailplane spar flange vi
Check grain slope of all spar flanges after being cut. I may be using other wood and redoing. I am not happy with what I see despite testing at specified values. Photos from test on 11.22.2009 of discarded spar flange with the worst grain slope. The other two may still be discarded and redone.
POSTED TO OSHKOSH365 Hello,
I am interested if there is anyone here who has some real expertise in wood grain slope. I have read the EAA wood book, and have numerous texts, all with some slight variations on the grain slope values ranging from 1:20 to 1:15 with various localized deviations allowed.
I have tested a discarded tailplane spar flange, this flange had the least favorable grain slope at about 1:10 localized in the center across the width (not depth) of the tailplane spar flange.
Despite this being my discarded spar flange it tested at 9,900 PSI to break with this 1:10 localized grain slope.