This was an interesting exercise in problem-solving. The verticals at Station B-P have a dogleg in them. Also, the apex of the dog-leg captures the horizontal tube that is the bottom of the instrument panel. It has to be level and exactly 22 inches above the datum centerline. Also, since the tubes have dog-legs, the also have to be aligned to themselves and the fuselage. Think of standing with your hands on your hips and moving your elbows forward and backward. At some point they are aligned with each other and that's what I'm making the jig for.
I started by putting two wood blocks at the bottom tube with a 1/16th piece of metal between the tube and block to form a stop. I then placed a 2x4 on the wood jig and clamped it. I put a piece of OSB on top of the lower longerons (they are perfectly level, of course) at the stops I made and then moved the 2x4 up to where it lined up the OSB to the proper angle for the verticals. Once the angle was established, I fit each vertical and then secured them with a conduit clamp. The first tube took a little over an hour to fit as the apex has to be exactly 22 inches above the datum and I didn't have room for a second chance (i.e. no more tubing on hand). Once these were done, I tacked them in place.
