Mechanic with dancer
The unwinder controls the motor of the bobbin and the feeder is controlled by a different motor. In between is a dancer, that keeps a constant tension on the foil. The unwinder moves the bobbin, to keep the dancer in the middle position.
After a configured start movement is completed, the automatic mode starts.
Moving To the Reference Position
This start mode is for dancer mechanics. It brings the dancer into the middle position while the feeder stands still. The unwinder moves the bobbin to tense the foil. If the dancer does not react, then a diagnostic message occurs. When the dancer reaches the middle position the start movement is finished.
The user can also move the dancer to the minimum or maximum positions first, to measure the radius of the bobbin (xRadiusMeasurement=TRUE). First the dancer is moved to the maximum position. The positions of the bobbin and the dancer are stored. Afterwards the dancer moves to the minimum position and the dancer and bobbin positions are stored again. Now the radius of the bobbin is calculated and set as the start radius for the automatic mode and the dancer is moved to the middle position.
This start mode is used to exchange an empty bobbin with a new one.The dancer is at the minimum position and the feeder is already moving. The dancer stands still because the foil is not connected to the feeder. As soon as the foil is connected to the feeder the dancer of the unwinder starts to move, because the feeder is pulling the foil while the bobbin stands still. After this, the unwinder accelerates to reach the necessary speed. The acceleration must be high enough, so that the bobbin has the required velocity before the dancer reaches the configured reference position. This position is set by the user.
