[Peter Johnson]

294 used a 20:1 single threaded bronze gear/steel worm combination made by Boston Gear in both 2010 (for our kicker pullback) and 2011 (for our lift winch).

In 2011 we made the mistake of going with a cast iron worm gear (for cost reasons) on our practice robot; turns out we were operating with too high of a torque for cast iron and shredded the gear; cast iron is only rated at something like 25-50% of bronze, and our practice robot telescope wasn't as smoothly operating so it put more load on the gear. We never had an issue with it on our competition robot (as it had a bronze gear).

I'll post pictures/CAD of our 2011 gearbox if anyone is interested in more details. We used two banebots into a ~4:1 pinion/spur reduction, and a 20:1 worm reduction directly driving our 4" diameter drum. Good speed and absolutely no backdrive (we notched a slot in the end of the worm shaft so a power screwdriver could be used to manually raise/lower if necessary).