Trussed Mendelmax Y belt tensioner

This is a stronger trussed Y-belt tensioner with double tensioning screws to provide some belt tracking control. It's an iteration of kludgineer's Mendelmax 1.5 part.

I have a heavy Y assembly and am trying to use as high a belt tension as possible, maybe even with a wider belt in future. Anyway, my (over)tensioning bent Simonious' wider version of the Mendelmax 1.5 Y belt tensioner, and once the bending started, the belt always rode to one side and dragged. This part is intended to fix both