DYNAMIXEL backdrivability

[vineetmathew2003]

I am building a gripper manupilator and am planning to control it using DYNAMIXEL motors. Since the specs state it has torque saturation capabilities it seems ideal. I wanted to know if the motors are back drivable. Im eyeing the AX-12a motor. the required torque is atleast 800mNm. I want the motors to rotate in the opposite direction if enough external force is applied. I have also looked at MAXON motors but they seem to expensive. It would really help me out if someone could contrast the advantage of using MAXON over DYNAMIXEL or viceversa.

Thanks!

[jwatte]

Yes, the AX-12A is a simple brushed motor with a simple spur gearbox.
Btw: note that the 12 kgcm rating is maximum stall, and should only be met for a few seconds.
The long term duty cycle rating is between 0.2 and 0.25 times that rating. (This is pretty common for most electric motors; continuous torque/current rating is much less than peak torque/current rating.)

A Maxon motor is just a motor, without any sensor feedback or driver circuitry or (usually) gearbox. They are not comparable as integrated units.
The Dynamixel MX series, and the Dynamixel XH series, use Maxon motors internally. Those still use spur gear boxes that are back-drivable.
The Dynamixel Pro series may also use Maxon motors, but use cycloidal gear boxes that are not back-drivable.