Today I was visiting with an RV-9A builder as he was ready to find the angle of incidence on his project. Does the measurement 4-5/64" ring a bell ? It's the measurement for determining rear spar height from a horizontal plane which sets the angle of incidence for the main wing. Wow, 5/64th is a figure I had never worked with. It gave me a whole new appreciation for builders of the new generation of RV's.
I couldn't get it out of my mind so unfurled my -4 plans 1150, published in 1981, and searched for what was then the generally accepted measurement of the day. It seems Van's at the time favored 1/8 or generally the smallest was some version of the /16th. I did find a 13-11/32 and 13-27/32 on page 13 of my plans concerning the center bulkhead wing carrying structure. Van kept measurements pretty simple and quite effective throughout those plans so what happened?
I'm pretty sure I would have made that 5/64 into a 2/32 or better yet, 4- 1/16 and call it a day. I think I had it pretty easy back in the day.