This retrofit plan has been designed for the Jet JTM-1 and with slight modifications the procedure outlined here could work for other machines also . In a recent test case, the parts and mounts in this design have been found to fit a Grizzly knee mill as well.  This set of instructions, drawings, timing belt drive part numbers, and pictures are meant to help guide the owner of a typical knee mill clone to adapt the Logitrol Large servo system to their machine. No warrantee is expressed or implied, nor do I accept responsibility for any bodily injury, equipment damage, residence damage, work site damage, property damage, or loss of wages anyone may incur in using these construction plans. Use this set of plans entirely at your own risk.