The elevator spar face needs to be set vertically in relation to the chord of the elevator. This required careful sanding to fit. I got some 50 grit sanding belts and glued one to a flat board 21 inches in length. This "shooting board" worked well, but it's not a quick process. It required placing and removing each spar multiple times, and checking for vertical each time. When I finally got it fitted, I hot glued both spars to the lower elevator skin, then raised the entire assembly high enough to rotate the elevator to check for fit and easy movement. After a bit of trimming, free movement was clear. I did need to adjust the skins just a bit, but am satisfied that it's just fine for final trimming after assembly.
