Before adding the remaining ribs, I pinned the aluminum angle against the T/E so it wouldn't be pushed out of alignment. Each rib can now be fitted into place but not glued yet. As expected, each rib needed to be sanded to fit without pushing the T/E out. Now I placed the angle on the top of the ribs. Each rib should touch the angle to be properly aligned, either pin the ribs or use a small piece of balsa under the ribs to hold them in place. To keep the T/E aligned, I again place the metal ruler on the T/E and make sure its against the ruler as I glue the ribs to the T/E and to the spar. What all of this accomplishes, is that the T/E is straight from the root to the tip, is not bowed outward and all of the ribs are even from root to tip. It takes a lot longer to explain that to actually do.