Topic Tag: rpm

Hi guys, I am working on a shredder design at the moment that is a little different than most others, its based on the small Filamaker shredder that Marek Patel has copyright free Cad designs for on his website : Free Shredder Cad Files I take no credit for the design just sharing it - *** anyway - back to the question **** I am looking for a way to auto reverse a motor if it gets jammed for a specific amount of time before going forward again. Is there a way of doing this ? My setup - (plan only @ this stage) 5.5kw motor on a VFD geared at 23 rpm (It will have a 1667 Nm of torque roughly, as not only am I shredding plastic but also waste wood and tin cans etc) or a hydraulic 7.5kw motor with adjustable speed depending on flow rate. The shredder is constructed out of 21mm steel and the blades are made from 21mm hard faced steel (or Hardox - not decided yet) The danger is if it gets jammed ...it can break the drive shaft. I was thinking if the RPM drops below x amount it would reverse for 5 sec then go forward ? or like mentioned it jams and auto reverses any thoughts or ideas anyone ? many thanks Mike