Quote Originally Posted by terry1956 View Post
hi, the motor runs ok off the machine. the motor can move the gantry if I help it a bit, but is not able to move it unaided. I have tried retuning it in mach3 but I think that there is just too much weight for the motor to deal with. the drivers are just 4.3 amp units from ebay
Just saying the drives are 4.3A does not say what they are. If you up the voltage you will get more power but if the drives can not handle that !! I doubt putting bigger motors on will solve your problem.