Holds bottom lock nut in place on wood beds with the three quarter-circle edges, as in the Makerfarm Prusa i3v kit.
My first design, go easy... printed, tested, in use. Works great, and much easier.
Just print with some brim rings to hold in place, 3X.
** About 2 millimeter clearance to the frame on left side of the bed on my i3v... make sure your bed clears before testing with power! ***