Let's say I have a 300 rpm motor and a roller connected to it's shaft and I would like to use it for pulling fabric from a printer-kind machine. But think that printer's printing speed is changing according to printed surface and I want this motor's shaft to spin freely when opposite load occurs on this roller by fabric.
So basically, if printer prints 100rpm long fabric, 200rpm of motor will spin freely as printer pull other side of fabric. When printer prints another length of fabric, motor will roll again. Roller (or idler?) should be able to spin asynchronously.
I don't know much about bearings and mechanical parts so my question might be weird, but I heard some kind of bearing can solve my problem. I tried to explain but sorry if it's nonsense. Thank you for your help in advance.