[InFlight]

Originally Posted by Chris is me

You can definitely screw this up, and several teams have had failures using 9mm belts and 24T or smaller pulleys in the drivetrain. If you're not sure I really would go 15mm.

That this gearbox doesn't fit two 15mm pulleys is one of the reasons I haven't used it. It's a lot of space to ask for, true.

Use of small pulleys really decreases the torque rating of these belt drives. Compared to a 36T pulley a 24T is about a 53% reduction in capability, while a 22T is down to ~47%.

A 15 mm wide belt is 40% stronger than a 9 mm belt. The extra strength may help some, but it is still poor compensation for a bad design.

For smaller pulley sizes, it would be better to go down to a 3M belt since you would have more teeth in contact and there would be less of torque rating decrement.

I would encourage everyone designing belt drives to take some time and understand the product, and engineering equations involved, before slapping it in to their design and hoping it will work.