Yes, we did use one on our Recycle Rush robot at the IRI. We added the ability to pick up the 3rd can in order to manage a 28 point autonomous. The throttle motor drives a 3D printed sprocket on a hex shaft with a 10-turn pot mounted on the other end. We had fairly strong string wrap around the hex shaft and it had no problem lifting the can off the ground in less than 2 seconds. We did a 28 point autonomous a couple of times (see match Q4 of the 2015 IRI) The lifting mechanism was strong enough to lift the can right up sideways and bust the string (Q73) when our autonomous didn't complete properly. This messed us up big time and we scored 0 points for our alliance that round. Anyways, the throttle motor can certainly work and using a 3D printed gear to get a 15:1 gear ratio worked very well. I'm pretty sure the gear was strong enough to stall the motor without breaking teeth. You can see the 3D image here.
http://www.cybercavs.com/throttle-motor.html
Maurice Veldhuis
Engineering Mentor, team 4678, Woodland CyberCavs