Hi Tweakie
I forgot to mention that my machine linear movements are a mixture. The 2 sides of the X axis and the Y axis run on module 1.5 racks, the pinions are 20 tooth mounted on a 60 tooth belt driven gear, the motor has a 20 tooth belt gear pulley. The Z axis is a direct drive form the motor to 1/2" - 10, 5 start acme screw running through a "Dumpster" nut.
Regards
Gary