I've built several Twister wings on the Adjusto-JIg. I set the rod hole jig so that the spars can be added while the wing is in the jig. I always put the straight part of the wing, generally the trailing edge, in the fixed end of the hole jig. In the case of the Twister either end will work. Be sure to only put the same end in the fixed piece for all ribs. You have to adjust for the center ribs as they are smaller to accommodate for the center sheeting. Also keep the rib numbers, stamped or lasered, facing the same way for all ribs. A pass of sandpaper over die cut ribs will help. After drilling the holes and your arthritis calms down put a rod in each hole, pull all the ribs together to see if the ribs need any truing up, do this with the rods on the jig stanchions so things are aligned. Watch for the center ribs just be sure the leading edge notches line up with the other ribs. Truing up the leading edge notch and trailing edge helps a lot while the ribs are in the rods. Setting the jig for the rib spacing just measure the plans, subtract 3/8" or whatever the thickness of the stanchions are and cut some cardboard spacers to put between the stanchions. Easiest way I've found to set the jig up.