8 mm Rod 12-Position Detent Knob
A print-in-place indexing knob that clamps to an 8 mm smooth rod and clicks through 12 positions, 30° apart — for manual pan axes, jig stops, selector shafts and hand-turned leadscrew axes that need repeatable increments instead of free spin. The bolt-down stator ring (Ø50 mm, four M4 clearance holes on 60 x 28 mm ears, 79 x 50 x 30 mm overall) carries the detent notches; the rotor prints inside it with two 2.5 mm compliant spring arms and locks to the rod with an M3 heat-set insert and grub screw.
mechanism 8mm-rod detent indexing-knob