Makerbot Replicator 2 Bed Leveling Knobs (rev 2)

These press on top of the stock knob that came with my Makerbot Replicator 2. The internal bore allows for the knob to be installed at the end, so it's not a press fit from the top of the bore, only the last 2.5mm. The bottom of the bore has slight serrations, an attempt to match the knurl on the stock knob.

The outside of the knob is a tapered serration, 20 per revolution. Doing the math, one external tooth equals approx 0.001" (screw is M3x0.5mm, so 1 turn = 1/2mm or .020")

The taper is