Built up ailer rib / spar / counterweight structure. Disassembled, deburred, and riveted structure together. Completed bend of aileron skin - here I had a problem. Beyond the PITA factor of getting this bend correct: The aileron skin had a very small ding right at the inboard trailing edge. The dig must have work hardened the material a bit since a crack formed during the bending process. I decided to cut out that corner of the aileron and make a trim tab (which came out very nice). However, after thinking long and hard I decided that I am going to just rebuild the aileron and go with the spring-bias trim.