Ok, I get it and agree that ideally I would eliminate as much backlash in the machine as possible. And believe me, I'm working on it. However I don't think you can completely eliminate backlash - some always exists otherwise the mechanism would bind up. Additionally, I'm not working with the best machine to begin with. So my options are limited.

I just wanted to warn others who may be considering going this route that although some of the SALES LITERATURE for Mach 4 says that it does backlash compensation, it DOESN'T. And that before you spend hundreds of dollars on this stuff, you should be aware that it may not work as you expect.

Thank you Gerry for recommendations on alternatives to Mach 4. I had difficulty getting LinuxCNC working on this machine and ultimately installed Windows so I could run Mach 4. It appears that UCCNC requires that I change out my BOB entirely which is undesirable. Although I will keep it under consideration if I can't get the backlash in the machine reduced to an acceptable level.

Thanks guys!

>Matt