Own an X-Carve with the Acme Z-Axis? Free Radical Labs designed a simple knob that fits over the hex nut on the end of the shaft. Since we believe in open-sourced objects, Free Radical Labs is offering the .STL file for download for free or you can purchase one from us that we've 3D printed. If you are kind enough to purchase these from us, there is no cost to ship the adjustment knob. We will ship it first class mail.
Note: The support structure from the print may be left in the knob - its super easy to remove with some small pliers.