Thank you so much for the answer, and thank you very much for the whys. So much easier to learn when you know why you need to make the suggested changes!
Sub-note in case anyone else is looking for this info: I forgot to put this information and and gilshultz mentioned the different options. Motor is bi-directional. It will wind up 8-12 inches of cord to open the doors, hold and then unwind to let the doors close normally. Using vex motor controller 29 to talk to the motor with the arduino h.servo include.