A method of homing motion axes in a radiation system uses a motor and one or more hardstops. A load is driven by a motor to move toward a hardstop during which an electrical parameter of the motor is monitored. A reference position for the motion axis is defined when the monitored electrical parameter reaches or exceeds a determined value. Alternative to monitoring the motor electrical parameter, the motor velocity may be monitored during the motion and a reference position for the motion axis is defined when the monitored motor velocity falls to or below a determined value. Alternatively, the load velocity may be monitored during the motion and a reference position for the motion axis is defined when the monitored load velocity falls to or below a determined value.