Flying Shear Motion Profile Tuning

Tubes have to be cut to length while they are continuously conveyed. The cutter must accelerate to the tube speed in a very short time, make the cut and then return. Any speed mismatch causes a skewed cut or a length error. The tube also vibrates slightly during conveying, so the servo has to filter that out before it follows.

We wrote the motion path ourselves in EtherCAT CSP mode and achieved real-time synchronization with the servo motors. The cycle is divided into five segments: acceleration and catch-up, synchronized constant speed, cutting, return and standby. Using the waveform monitor we tuned the acceleration and deceleration times and the length of the synchronized zone segment by segment, and added protection logic for the trigger point and for manual cutting in the return zone.

• EtherCAT CSP mode
• Servo motors
• Flying shear
• Waveform monitoring tool

• Dynamic fixed-length cutting for tubes from 1000 to 6000 mm
• Precise alignment in the synchronized constant-speed zone
• Manual cutting available in the return zone

Cut length is now stable. All tuning is based on the waveforms, so any segment that is off is obvious at a glance, which saved a great deal of commissioning time.