James : We do not know your motor rating, so we assume less than 1 amp @ 12 volts if it is more the same design will work , but a pass transistor and heatsinking will be needed. Still far better than a resistor The only other thing you might need to do is spike the motor to start it , use an r/c drive to pull the voltage high then let the regulator hold the voltage. if you need to do this, protect the regulator from reverse bias during startup with a series diode rated at more than the inrush for the motor hth Terry