Z-Axis Knob for Printrbot Simple

thingiverse

This Printrbot Simple owner sought a knob for z-axis adjustment due to limited clearance around the screw. They found a solution in a small knob that screws onto the top of the z-axis rod, which should also fit other 8mm threaded rods. The center hole is 6.75mm and can be tapped to M8x1.25; secure the knob by holding the shaft with vise-grips while carefully threading it on. An update advises that clearance issues might arise if there's significant Z-wobble at the top, so a slightly smaller version is available for extra space. The smaller version was tested and works better without any problems. Print settings are 0.3mm layer height, 0.3 rectilinear infill, 3 shells, and PLA material. Three shells are crucial to avoid cracking into the infill while installing the rod.