Thanks for the reply Dale. The issue I have is I already have the controller and want to put it to use . I did some calculations but don't no if they are right,I worked out the motors spin 1000rpm and 600oz torque if I did a 4:1 ratio this would give me 2400oz torque and 250rpm and using a 20 tooth mod2 pinion which is approximately 125mm travel per rotation would give me a max speed of 31250 mm minute. Now that is quick for what I need and that is also the motors running flat out. I don't no what speed I should run the motors for continuos use . I'd be happy with 20000mm a minute but I need it to pack some punch is there any way these motors would be capable of moving around a 200 pound gantry without them choking up. Danny