pic: FRC971 2011

[AustinSchuh]

Originally Posted by sdcantrell56

What pitch belt did you use and how did you tension it? We started off with XL belt and ran into issues skipping it at start up. We finally switched to #25 chain and have had no issues since

9mm wide 5mm pitch GT2. If you read the docs on the belts, the GT2 holds significantly more force before skipping than the XL. For our claw, we aren't tensioning it, and calculated the center distances correctly. For the elevator, there is a screw tensioner that pulls the ends together inside the carriage.

A 20 tooth XL pulley (1/4" wide belt) is rated to 4.6 in-lbs. A 20 tooth GT2 5mm pitch (15 mm wide belt) is rated to 93 in-lbs. An order of magnitude of difference. The two belts I just compared aren't exactly the same in everything but pitch, so the comparison isn't perfect, but it gives you a pretty good idea on why we chose the belt we did. Our elevator should be able to pick up ~100 lbs before the belts skip.