We initially used a sliding gate opener for our RoR and that died pretty quickly, not to mention the 100amps it draws on start up when the could spin up.
We then bought a replacement as found here with a reduction hear, and machined a brass gear foe the track. Draws little power and is rock solid.
http://www.crestmi.com.au/DC_precisi...p#Z55D300-24GU
Stefan