We used the Van Door moter last year. We attached a large sprocket to the shaft that is on the output side. A word of causion: the moter may be strong and may have a worm gear, but it also has a break that prevents both the gears from breaking and from it exceding about 30 ft-lbs of torque. We had the moter directly contolling our arm last year with about an 8:1 gear ration in the sprockets but it was too much for the van door and it couldn't lift the arm very much and was very hard to control

. For lighter uses, like pulling and the like, the van door is very good, but don't try to control a large arm with it like we did.
