Attaching the motors to the x-y rail and linking them to the pulleys was a problem. Not having formal pulleys for the DC motors,  I used the existing wheel on the stem but the rubber band belt tended to slip off. Working on that problem. Also discovered that a DC motor alone will not hold up the claw with no juice applied. The weight of the claw simply spins down the spool (rigging a spool to the short stem of a  motor is also a problem). It seems I will need a worm drive because that locks in place when the motor is off. In the process of  finding one.