This is a simple remix of Charles_Snyder's leveling knob. I've simply made it a couple MM deeper to grab the entire body knurling, and made the spokes & finger surface slightly thicker too. The original is wonderfully efficient but I didn't like the adjustment knob not fitting completely inside the part. I'm printing them at 25% infill and it feels right to me. Removal and pressing in the knob is required. Firm hands, or a bench vice.

Please print 1 and test fit first. Don't be like me and print 4 solid knobs at 100% infill and then find out they're off by one millimeter.