steelplc

Yeah that would be the correct way to do it. However the company I’m working for doesn’t want to have to buy anything extra or mechanical to add to the current system. I think I’ll be able to do it by reading my coil diameter with a laser sensor in inches and dividing my torque feedback(in-lbs) from my drive by that radius(in) to get a number (+- 10%) representing the tension in pounds force.

So I'm having trouble writing a FBD within my current program for a slitting line. I need to keep a constant tension on my web as it is being recoiled onto our recoiler. I wrote a simple program using a sensor to read the growing rate of the coil to get a radius and I have feedback on my torque on the recoiler motor. The simplest math for this application without getting into anything too fancy should be Tension(lbs)= Torque(ftlbs)/coil radius. only problem is when its less than a foot then my calculation is thrown off and it actually shows tension goes up until it reaches the one foot mark then it seems to scale correctly. Do I need to scale something else? Any help on this would be appreciated.