A motor stop mechanism serves as a stop limit for a motor including an output shaft. The motor stop mechanism includes a motor mounting surface to which the motor is attachable, where the motor output shaft is positionable through the motor mounting surface. A coupler is fixable to and rotatable with the output shaft, and a threaded drive shaft is fixed to and rotatable with the coupler. A trunnion threaded on the threaded drive shaft is displaceable on the threaded drive shaft with rotation of the threaded drive shaft. The trunnion is displaceable between a retracted position and an extended position by forward and reverse rotation of the threaded drive shaft. A stop limit defines the extended position of the trunnion. In use, when the trunnion reaches the stop limit, the motor is stopped.