I studied the plans for some time before installing my wing centersection spars. I heard all the old stories about the banana boat syndrome of the upper longerons and all that. There is a very simple and accurate way to do the job that involves no math at all and can be done with a simple bubble level. I did a writeup in the KR newsletter years ago and repeated it on the net a time or two. After I had my centersection installed I purchased a SmartLevel (digital level) and found the wing to be within 1/10 of one degree.
Look at the drawing for the 48" rib. It has the cord line and spars drawn. Notice the cord line intersects the spars at the plans recomended 3.5 degrees incidence. If you want to change that to something less simply redraw the spars on the 48" rib and proceed as follows. When setting the spars in the boat use the firewall as a reference as suggested in the plans. I'd suggest you use this reference for setting the Horz stab spars also. Anyway, mount the forward spar in the boat, level side to side, equal distant from tip to tail, and plumb on the rear face of the spar. Insure the boat is level side to side also. Epoxy the spar in place. Cut the 48 inch ribs and bolt them together for final shaping to insure all are the same. Mark the cord line and spar locations on the top rib and make references across the edges of the other ribs. Insure the spar is plumb at each rib location. If not make adjustment to that rib only to compensate. If you use Mark L.'s method of making the ribs one piece with the hump, mount the ribs to the front spar. Once epoxied in place use the ribs to locate the rear spar. I cut my ribs in three pieces and use the center section of the rib epoxied to the forward spar to locate the rear spar. If you are accurate in transfering the rib drawings to the actual ribs it can't help but work out. Your results may vary but mine flies just fine, thank you. :-) Larry Flesner N 211LF Carterville, Illinois
