[Monochron]

Aluminum HTD pulleys with more hearty outer walls. Almost all of our larger diameter pulleys had the wall ring pop off at some point during the season. The belts themselves very rarely slipped off as they were fairly well aligned, but I would love to have not had to deal with it over and over.

If they can't get away from the ring design of the walls, maybe make the walls a little larger so that you could tap and screw it back on after it pops off? It's doable right now with (I think) a #4 screw, but something larger would be nice to work with.