This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/6mAPxb2htAk

We have an x-carve in the makerspace in the GE facility where I work. This is now in use as a Z-axis adjusting knob. The base has a ~10mm hex recess in it, which fits nicely over the nut on the top of the z-axis ballscrew on the x-carve.

This is Bre's design, that I added the hex cutout and some text to. "Not-So-Hidden" message in the base.