A modified Prusa bar clamp that is able to slip onto both threaded and smooth rods without need for vertex disassembly. Since M8 & 5/16" are so close (8 mm vs 7.938 mm), these should be usable with both metric and SAE.
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Imported from Thingiverse: https://www.thingiverse.com/thing:5786
Original creator: Ahasuerus