Im having an issue with my dancer rollers at the infeed... They keep limiting out. Maintainence tech replaced some boards and the top dancer finally leveled out, however the lower one is still going to limits. When it is topped out I can bring the tension down a few points and it will ride in the middle for a few minutes before it then drops to the bootom limit. Any suggestions would be GREATLY Appreciated. Thanks
I can not say for sure what your particular problem is but I will comment on dancer rollers. I am assuming that the dancer roller you have has some kind of air cylinder mechanism on it.
Dancer rollers do three different things. 1. They act as a small accumulator that absorb variations between the amount of paper going to the press and the amount of paper coming from the reel at the payoff. 2. They are used to control the payoff speed. When the dancer moves to one side of the set point position it tells the payoff to provide more paper. When the dancer moves to the other side of the set point position, it tells the payoff to provide less paper. Payoff speed control can be done through a motor drive or by friction brakes. 3. The dancer provides the web tension to the web via the air cylinders or what other method that loads the dancer.
Ideally the dancer roller should provide consistent web tension at all positions of its travel. If you are using air cylinders, they should not have flow controls on the exhausts since this will cause variations in web tension as the dancer moves.
Your problem can be caused by multiple issues. The feedback system is not working properly. This can be a problem with the pot that sets the neutral dancer roller position, the PIV control settings on the card or the card itself. The operation of the payoff speed control system can be faulty.
Please remember, with a dancer the payoff does not control web tension, the air cylinders or in some cases the springs on the dancer does. It is also possible that if you set the air pressure (or spring loading) too high, it might overpower the payoff speed control system.
Hope this helps and good luck.
