Hello, I am rebuilding an older CNC with slo-syn stepper motors. The specs for the motor are:

200 Steps per revolution
Holding Torque = 770
Voltage = 1.4
Phase Resistance = .200
Current = 7.0
Phase Inductance = 1.49

I have Gecko GR214V 7AMP drivers powered by a 48V power supply. The motors will heat up within 10 minutes of just sitting there, where I can not even touch them. I am concerned that they have told me to get the wrong power supply. I am new to this, so please bear with me. Is there a calculator to figure out what the correct power supply voltage should be? Or does anyone no what I should be using. I have a feeling this is too much voltage. Thanks!