Quote Originally Posted by Jonathan View Post
Belts offer numerous advantages for driving ballscrews, the stretch is almost invariably negligible there since the belts are very short. However if you're using belts to replace ballscrews (i.e. the subject of this thread), then the stretch will be a factor - otherwise belt driven machines would be good for machining more than just soft materials.
Oh here we go.!!! . . . My machines is nearly 1500mm wide so thats over 3000mm long belt and stretch hasn't affected it yet.! This belt has been on machine probably coming up 2yrs, the first which I damaged had been on over 2yrs and hadn't stretched in that time.!

It's all relative to the machine and work load and I know, Again thru experience, that this size machine doing the kind of work John intends then it will be a very very long time before belt stretch even remotely comes into the frame.!! . . . Yes they clearly will stretch over time that's a given but ball-screws wear-out and I know a good quality belt will last just nearly has long has any Chinese ball-screw.!!