I wanted a quick release lever for my Makita lawn mower, to make it faster and easier to fold and unfold it than turning the knobs fifty-eleven times. For this reason the actuation is quite large.

Insert the pivot into the cam lever. Insert an M8 nut or M8 socket head bolt into the pivot.

NEW: I've added a version made for use with an M8-20mm barrel nut, see second print profile. I guess this would work with any thread size as long as the diameter of the barrel nut is 12mm.