Monofilament nylon is produced by an extrusion process that results in an output of filament at a constant rate. The product is wound onto a bobbin by a ballscrew-driven arm, which oscillates back and forth at constant speed. The arm must reverse rapidly at the end of the move. This application provides the required controlled tension and ballscrew speed throughout the process.

Machine Objectives:

• Controlled tension on monofilament
• Simple operator interface
• High throughput

Motion Control Requirements:

• 2 Axes of coordinated motion
• Linear interpolation
• Constant torque from motor

Application Solution:

The prime requirement of the bobbin drive is to provide a controlled tension, which means operating in Torque mode rather than Velocity mode. This requirement leads to the use of a servo operating in Torque mode even though a servo in Velocity mode might be recommended with an overriding torque limit. Therefore, the servo normally operates as a constant-torque drive, but if the filament breaks, the velocity is limited to the programmed value. The traversing arm is usually driven by a smaller servo.

Product Solutions:

• Indexer - 6K*
• Drives - 2 GV-U6Es**
• Motors - 2 N0702Fs**
• *The AT6450 PC-based servo controller has also been used in this type of application.
• **The APEX20/APEX40 and TQ-10 servo drives with the SM233BE motor have also been used.