In order to drill the cap strips to the web, you have to set the dihedral angle at the same time. This required accurately setting up the level line of the center section (I did this with a laser) then setting the 5 degree dihedral angle based on that line. Image 2 shows the laser measurement of the angle. The key thing will be to make sure the left wing exactly matches the right. My setup pins fit very tighly, so I spend a fair amount of time making sure the caps were level in all directions, and that the pins were not binding when I finally drilled them. Also, I drilled all the holes after I fabricated the end flanges that try to hole the whole assembly in alignment,
