Hi Richard the motor is a stepper which is connected to a capstan drum of diameter 0.035m the stepper doesn't have any power off brake which is the same reason I wanted to design a system so that when the power goes off it doesn't drop as I mentioned in my post I was looking to design a torque amplifier where the stepper shaft is connected to capstan drum which is wrapped with a cable and passes around two pulleys one of them is a output shaft and I connect my another capstan which drives the z axis mechansim to this output shaft I was thinking since there will be more torque available at output shaft will that be enough to hold the stage from dropping off when the power goes down ? I am open to advises as I want to develop this system and make it work