Beckhoff PLC & Motion Control for High-Speed Flying Shear in Roll Forming Machines
Introduction — Why Beckhoff Is Used in High-Speed Roll Forming Machines
High-speed roll forming lines require extremely precise motion synchronization between moving machine components. Systems such as flying shears, servo feed punches, and automated positioning units demand fast control cycles and accurate real-time communication.
For these reasons, many modern high-performance roll forming machines use Beckhoff automation systems.
Beckhoff PLC platforms are known for:
- ultra-fast control cycles
- advanced motion control capabilities
- EtherCAT real-time networking
- scalable PC-based control systems
These systems are particularly well suited for flying shear synchronization, where the cutting carriage must match the speed of the moving strip before performing the cut.
Beckhoff automation is commonly used in machines such as:
- high-speed roofing panel roll formers
- structural profile lines
- automotive roll forming systems
- complex multi-axis forming lines
Understanding how Beckhoff systems operate is essential for engineers designing or maintaining high-speed roll forming machines.
Beckhoff PC-Based Control Architecture
Unlike traditional PLC platforms that use dedicated hardware controllers, Beckhoff systems often use PC-based control.
In this architecture, the PLC software runs on an industrial PC while real-time control tasks are handled by specialized runtime software.
A typical Beckhoff automation system includes:
- industrial PC controller
- EtherCAT communication network
- servo drives and motors
- distributed I/O modules
- HMI operator interface
This architecture allows very high processing speeds and flexible system configuration.
TwinCAT Automation Software
What Is TwinCAT?
Beckhoff automation systems are programmed using TwinCAT (The Windows Control and Automation Technology).
TwinCAT is a software platform that converts an industrial PC into a real-time PLC and motion controller.
TwinCAT integrates several functions into one engineering environment.
These include:
- PLC programming
- motion control configuration
- industrial networking
- system diagnostics
TwinCAT allows engineers to control complex machines with extremely fast response times.
EtherCAT Networking
What Is EtherCAT?
EtherCAT is a high-performance industrial communication protocol designed for real-time automation systems.
EtherCAT allows devices to process data as it passes through each node in the network. This approach significantly reduces communication delays.
Typical EtherCAT cycle times are:
- less than 1 millisecond
- sometimes under 100 microseconds
These speeds make EtherCAT ideal for motion control applications such as flying shear systems.
EtherCAT Devices in Roll Forming Machines
Typical devices connected through EtherCAT include:
- servo drives
- encoder interfaces
- distributed I/O modules
- safety controllers
Fast communication ensures precise synchronization between machine components.
Flying Shear Motion Requirements
Flying shear systems require extremely accurate motion control.
The cutting carriage must perform several actions:
- accelerate to match strip speed
- synchronize position with the moving strip
- perform the cutting operation
- decelerate and return to the start position
All of these actions must occur within very small timing windows.
Small errors can result in:
- incorrect panel length
- mechanical shock
- blade damage
This level of precision requires advanced motion control systems.
Servo Motion Synchronization
Beckhoff systems synchronize servo motion using real-time position feedback.
The control system continuously monitors:
- strip speed
- strip position
- carriage position
Using this data, the controller calculates the required motion profile for the shear carriage.
The servo drive then accelerates the carriage to match strip velocity.
Once synchronization is achieved, the cutting blade activates.
Motion Control Algorithms
TwinCAT provides advanced motion control algorithms that simplify synchronization.
These include:
- electronic gearing
- electronic camming
- coordinated axis control
Electronic gearing allows the carriage axis to follow the strip movement with a defined ratio.
Electronic camming allows complex motion profiles to be synchronized with the strip position.
These functions allow extremely precise control of flying shear systems.
Encoder Integration
Encoder signals are critical for flying shear synchronization.
Encoders provide real-time information about strip position and speed.
Typical encoder configurations include:
- measuring wheel encoders
- drive shaft encoders
- high-resolution rotary encoders
The control system uses encoder data to calculate when the shear must activate.
Reliable encoder signals are essential for accurate cut lengths.
PLC Programming Structure for Flying Shear
Flying shear control programs typically include several functional sections.
These include:
- encoder length measurement
- motion control commands
- synchronization logic
- shear activation sequence
- carriage return logic
The PLC continuously calculates position and velocity to maintain synchronization.
Advantages of Beckhoff Systems for Flying Shear
Beckhoff automation systems provide several advantages for high-speed roll forming lines.
These include:
- extremely fast control cycles
- precise multi-axis synchronization
- flexible PC-based control architecture
- scalable system design
These features allow manufacturers to build high-speed roll forming lines with excellent cut accuracy.
Common Flying Shear Problems
Even with advanced control systems, flying shear systems can experience faults.
Typical issues include:
- servo following errors
- encoder signal instability
- incorrect timing compensation
- mechanical friction in carriage guides
Diagnosing these issues requires careful monitoring of motion control data.
Commissioning Beckhoff Flying Shear Systems
Commissioning high-speed flying shear systems requires careful calibration.
Typical steps include:
- verifying encoder scaling
- tuning servo motion parameters
- testing carriage synchronization
- adjusting cut timing compensation
- verifying cut length accuracy
Testing must occur at gradually increasing speeds.
Preventative Maintenance for Flying Shear Systems
Regular maintenance improves long-term system reliability.
Recommended inspections include:
Monthly:
- inspect encoder mounting
- inspect carriage guide rails
- verify servo cable integrity
Quarterly:
- verify servo tuning parameters
- inspect blade condition
Annual maintenance:
- recalibrate motion parameters
- inspect mechanical wear components
Preventative maintenance reduces unexpected machine failures.
Benefits of Beckhoff Motion Control in Roll Forming
Beckhoff automation systems provide several benefits for roll forming machines.
These include:
- extremely accurate flying shear synchronization
- high-speed production capability
- flexible automation architecture
- advanced motion control tools
These advantages make Beckhoff systems ideal for modern high-performance roll forming lines.
FAQ — Beckhoff PLC Systems in Roll Forming Machines
Why are Beckhoff systems used in flying shear roll forming machines?
Beckhoff systems provide extremely fast motion control and real-time communication required for precise flying shear synchronization.
What software is used to program Beckhoff PLC systems?
Beckhoff PLC systems are programmed using TwinCAT automation software.
What network protocol is used with Beckhoff automation systems?
EtherCAT is the primary communication network used with Beckhoff systems.
Why is EtherCAT suitable for high-speed motion control?
EtherCAT provides extremely fast communication with very low latency, allowing precise synchronization between servo drives.
Can Beckhoff PLCs control multiple servo axes?
Yes. Beckhoff systems are designed to control multiple synchronized servo axes for complex automation systems.
How is flying shear accuracy verified during commissioning?
Engineers measure panel lengths at increasing production speeds and adjust synchronization parameters to achieve accurate cuts.