The UCD kit comes with the hinge slots already cut, and they seem to be aligned fairly well. The control surfaces all moved freely with no "snapping" action as they passed through neutral.

The CA hinges were installed with Balsa USA thin CA according to the UCD instruction manual, with the exception of widening the gap just enough to allow throws of at least 45 degrees in each direction. The instruction manual suggested a small gap - "just enough to see light through or to slip a piece of paper through". But with the hinges set this tight on my UCD, even 30 degrees of throw became a problem. Could the slightly wider gap have caused the failures?