I have been working with LinuxCNC and in the configuration wizard, that gives me .4rev/mm or 10.16 rev/in. For anyone interested, I also counted 20 teeth on the motor pulley and 40 teeth on the ballscrew pulley.
I got the machine to jog the other night. It was quite a sight to jog the machine on the x-axis .001" in one direction and then back .001" and see no backlash!
Daus