One of my teams has an axle that bares the whole load of their lift. They have taken the axle, cut out a flat section, and then drilled about a 1/3 or 1/4 down, allowing the set screw to set into. They plan on tapping two more holes into the hub to help as well. From all the practice, they still haven't had any problem with the axle. (They snapped a steel cable in half, not budging the set screw a bit.(That problem has been fixed.
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