Today I worked on completing the root ribs for the left wing. I worked on the rear rib first. I measured the 9/16 inch dimension from the rear spar and then fit the rib to this line. Using several .032 shims I aligned the rib with the spars and then clamped the rib to the fittings. After drilling the pilot holes I fit the reinforcement angles and pilot drilled them. Next, I added the remain holes to the reinforcement angles and transfered the holes back to the rib. The final step was to up drill, debur and rivet. For the tip rib I calculated the distance between the ribs using the skin drawing W18 and position the tip rib using the tooling hole, and the adjacent ribs. Having the spacing at the tip of the rib was helpful. The remaining steps were basically the same as for the rear rib.