Choosing the Right Cutting Technology in Roll Forming 

In modern industrial manufacturing, productivity, precision, and automation are no longer optional. Manufacturers operating in industries such as construction, automotive, solar energy, warehousing, steel fabrication, and infrastructure require production systems capable of delivering high output with minimal downtime. One of the most critical technologies enabling this level of efficiency in roll forming lines is the Servo Flying Cut system.

A servo flying cut mechanism allows continuous profile production without stopping the roll forming process during cutting operations. Instead of stopping the strip movement for each cut length, the cutting unit synchronizes with the moving material and performs the cut while traveling at the same speed as the profile. This significantly improves production speed, dimensional accuracy, and overall manufacturing efficiency.

Today, servo flying cut systems are widely used in:

• C and Z purlin roll forming machines
• Solar structure production lines
• Cable tray manufacturing lines
• Tube mill lines
• Guardrail roll forming systems
• Roofing sheet production lines
• Rack and shelving profile machines
• Slitting and downstream processing systems

As global competition intensifies, manufacturers face increasing pressure to reduce scrap, improve precision, lower labor costs, and maximize machine uptime. Traditional stop-cut systems are often unable to meet these modern industrial requirements.

This article explains how servo flying cut technology works in roll forming machines, including its engineering principles, machine components, synchronization systems, industrial challenges, optimization strategies, and key considerations when purchasing a production line.

What Is a Servo Flying Cut System?

A servo flying cut system is an automated cutting mechanism installed at the end of a roll forming line. Its primary function is to cut continuously moving profiles into precise lengths without stopping the production line.

Unlike conventional hydraulic stop cut systems, the flying cut unit moves together with the profile during the cutting cycle. This synchronized movement eliminates line stoppage and allows continuous production at high speed.

The term “servo” refers to the servo motor technology controlling the movement of the cutting carriage. High precision servo motors combined with encoder feedback and PLC automation ensure exact synchronization between the cutting system and the profile speed.

Main Functions of Servo Flying Cut Technology

The system performs several important industrial tasks:

• Continuous profile cutting
• High speed synchronization
• Accurate length control
• Reduction of material deformation
• Increased production efficiency
• Lower cycle time
• Automated operation

This technology is especially important for manufacturers producing large quantities of steel profiles where production speed directly impacts profitability.

How Servo Flying Cut Works in Roll Forming Machines

Basic Operating Principle

The working principle of a servo flying cut system is based on synchronized motion.

The steel strip passes through multiple roll forming stations where the desired profile shape is gradually formed. As the finished profile exits the forming section, it continues moving forward at a constant speed.

The flying cut unit detects the profile position and speed using an encoder system. The servo motor then accelerates the cutting carriage to match the profile speed exactly. Once synchronized, the cutting tool performs the cut while moving together with the profile.

After cutting is completed, the carriage rapidly returns to its starting position to prepare for the next cycle.

The process occurs in milliseconds and allows uninterrupted production.

Main Components of a Servo Flying Cut System

Servo Motor System

The servo motor is the heart of the flying cut mechanism.

It controls:

• Carriage acceleration
• Speed synchronization
• Position accuracy
• Return movement

High quality servo motors provide:

• Fast response time
• Smooth motion control
• High positioning accuracy
• Stable operation at high speed

Industrial-grade servo systems are essential for maintaining cutting precision during continuous production.

Flying Carriage Assembly

The flying carriage is the moving platform carrying the cutting tool.

Typical carriage components include:

• Linear guide rails
• Servo drive mechanism
• Ball screw or rack-and-pinion drive
• Hydraulic or mechanical cutter
• Position sensors

The carriage must maintain high rigidity to prevent vibration during operation.

Poor carriage design can result in:

• Inaccurate cutting lengths
• Blade wear
• Profile deformation
• Mechanical instability

Encoder Synchronization System

Encoders continuously monitor strip speed and position.

The encoder sends real-time data to the PLC controller, enabling precise synchronization between:

• Material movement
• Servo carriage speed
• Cutting timing

High resolution encoders significantly improve length accuracy.

In advanced systems, servo drives and encoders communicate through industrial fieldbus protocols such as:

• EtherCAT
• PROFINET
• Modbus
• CANopen

PLC Automation Control

The PLC system manages the entire cutting process.

It controls:

• Length programming
• Speed coordination
• Cutting timing
• Servo positioning
• Error monitoring
• Production recipes

Modern PLC systems also support:

• Remote diagnostics
• Production data tracking
• HMI touchscreen operation
• Integration with factory automation systems

Cutting Unit

The cutting mechanism can vary depending on profile type and material thickness.

Common cutting technologies include:

Hydraulic Cutting

Widely used for:

• Thick steel profiles
• Structural sections
• Heavy-duty applications

Advantages:

• High cutting force
• Reliable operation
• Lower initial investment

Mechanical Punch Cutting

Suitable for:

• Thin-gauge steel
• High speed applications

Advantages:

• Faster cycle time
• Lower maintenance
• Reduced oil usage

Servo Saw Cutting

Common in tube mill lines.

Advantages:

• Smooth cutting surface
• Reduced burr formation
• High precision for tubular profiles

Servo Flying Cut Workflow

Step 1: Material Feeding

Steel coil is loaded into the decoiler and fed into the roll forming machine.

The strip moves continuously through leveling and forming stations.

Step 2: Profile Forming

Roll forming stations gradually shape the material into the required profile.

The strip speed remains constant during production.

Step 3: Encoder Detection

The encoder measures line speed and profile position.

The PLC calculates the exact cutting point.

Step 4: Servo Synchronization

The servo carriage accelerates and matches the profile speed.

This synchronization is critical for maintaining cutting accuracy.

Step 5: Flying Cut Operation

The cutting tool performs the cut while moving together with the profile.

The line continues running without interruption.

Step 6: Return Cycle

After cutting, the carriage rapidly returns to its starting position.

The system immediately prepares for the next cut cycle.

Advantages of Servo Flying Cut Systems

Higher Production Speed

Traditional stop-cut systems reduce overall line efficiency because the line must stop for every cut.

Servo flying cut systems eliminate this downtime.

Manufacturers can achieve significantly higher production speeds, especially for shorter product lengths.

Improved Cutting Accuracy

Servo synchronization ensures highly precise length control.

Typical tolerance levels can reach:

• ±0.5 mm
• ±0.3 mm in advanced systems

This precision is essential for industries requiring tight dimensional control.

Reduced Material Damage

Stopping and restarting material movement can create:

• Surface scratches
• Edge deformation
• Shape distortion

Flying cut systems minimize these problems by maintaining continuous movement.

Better Automation

Servo systems integrate easily with smart factory automation technologies.

Benefits include:

• Recipe storage
• Automatic length adjustment
• Production tracking
• Industry 4.0 compatibility

Lower Production Cost

Although initial investment is higher, servo flying cut systems reduce long-term manufacturing costs through:

• Higher productivity
• Lower scrap rate
• Reduced labor
• Improved consistency
• Less downtime

Common Industrial Applications

Solar Structure Manufacturing

Servo flying cut systems are widely used in solar mounting structure production.

Profiles often require:

• High dimensional consistency
• Precise hole positioning
• High-speed manufacturing

Continuous cutting improves efficiency for large scale solar projects.

C and Z Purlin Production

Construction profiles require accurate lengths and high output volume.

Flying cut technology allows rapid production with minimal dimensional variation.

Tube Mill Lines

In tube manufacturing, flying saw systems provide continuous pipe cutting without interrupting the welding process.

This is essential for high-speed ERW tube mills.

Cable Tray Manufacturing

Cable tray profiles often contain punching operations combined with continuous forming and cutting.

Servo flying cut systems help maintain synchronization across the production line.

Automotive Components

Automotive roll formed parts require:

• Tight tolerances
• High repeatability
• Excellent edge quality

Servo-controlled cutting systems support these demanding requirements.

Common Production Challenges

Synchronization Errors

One of the most common issues is improper synchronization between the carriage and profile speed.

Causes may include:

• Encoder signal problems
• Servo tuning errors
• PLC communication delays
• Mechanical backlash

Solutions

• Use high-resolution encoders
• Calibrate servo parameters
• Improve PLC response time
• Maintain mechanical components regularly

Blade Wear

Cutting blades gradually wear during production.

Worn blades can cause:

• Burr formation
• Rough edges
• Inaccurate cuts
• Increased scrap

Solutions

• Use high-quality tool steel
• Schedule regular sharpening
• Monitor cutting force
• Use proper lubrication

Vibration Problems

High speed movement can create vibration in the carriage assembly.

This affects cutting precision.

Solutions

• Increase frame rigidity
• Improve linear guide quality
• Optimize acceleration curves
• Use balanced mechanical design

Servo Overload

Improper system sizing may overload the servo motor during acceleration.

Solutions

• Select correct servo capacity
• Reduce carriage weight
• Optimize cutting cycle
• Improve motion programming

Optimization Methods for Better Performance

Increase Line Speed Safely

Many manufacturers attempt to increase line speed without improving synchronization systems.

This often creates instability.

Recommended improvements include:

• Faster PLC processors
• High-performance servo drives
• Lightweight carriage design
• Advanced motion control algorithms

Improve Length Accuracy

Length accuracy depends on multiple factors:

• Encoder quality
• Servo response time
• Mechanical stability
• Material consistency

Using closed-loop control systems significantly improves precision.

Reduce Maintenance Downtime

Preventive maintenance is critical.

Recommended maintenance tasks:

• Inspect guide rails weekly
• Lubricate moving parts
• Check encoder alignment
• Monitor servo temperature
• Inspect cutting blades regularly

Implement Smart Automation

Modern roll forming factories increasingly use smart manufacturing systems.

Useful automation upgrades include:

• Remote monitoring
• Automatic diagnostics
• Predictive maintenance
• Production analytics
• ERP integration

Servo Flying Cut vs Stop Cut System