A friend of mine made a pretty neat project last year. It was a scale model of a fully working grain elevator. I was responsible for looking after all the electronic controls and computer interface. He built the elevator to show kids how a grain elevator works and has had it on display at several large exhibitions. The elevator is fully working and comes with a working G scale train and grain cars. There is also a remote control semi trailer which hauls the grain into the elevator. The elevator then fills the train and then the train goes to a spot where it can dump into the semi and then the semi drives into the elevator again.
The weak part here is the semi trailer, he has stripped the gears in the gearbox several times. When the kids drive the semi some are quite hard on it and ram into walls. The semi was never designed for this kind of use but it was the only one we could find that was close to the size. The semi has 1.5 inch diameter wheels and the tractor part of the semi is 10 inches long by 4 inches wide. We would like a speed of about100 feet per minute. He has asked me to find a better quality gearbox that will stand up abuse a bit better. The best source I have found so far is Tamiya, but the gears still don't look to robust.
I would really like to know where we could find either a complete more rugged semi, a source of a good quality gearbox or to be pointed to a different newsgroup if this is not the approriate one.
Thanks in advance