Abstract: Traditional stainless steel pipe production lines suffer from drawbacks such as high material costs, slow speed, and the need for coolant in sawing methods. Samkoon Technology, based on its self-developed PLC, HMI, and servo system, has launched an online laser pipe cutting machine solution. This solution enables high-speed, synchronized, and precise cutting of pipes, producing clean cuts with an accuracy of ±0.2mm. It helps companies reduce long-term production costs and supports subsequent complex functions such as expanding openings and cutting patterns.
1.Introduction
In the stainless steel pipe manufacturing industry, most production lines in the past used sawing machines. While this equipment is mature, it has several problems: the saw blades wear out quickly, making them high-consumption items; coolant lubrication is required during cutting, which is messy and adds to the process; and the cutting speed is relatively slow, affecting the overall line efficiency.
In recent years, laser cutting technology has begun to enter this field. It eliminates saw blade wear, eliminates the need for liquid cooling, cuts pipes faster, and produces a smoother cut. Simply put, while the initial equipment investment is slightly higher, it becomes more cost-effective in the long run. Therefore, laser-guided in-line pipe cutting machines are becoming an upgraded alternative to traditional sawing machines and have considerable potential for global adoption.
However, laser pipe cutting places higher demands on the control system. The equipment needs to ensure the laser head closely follows the pipe (this is “tracking”), and the positional deviation at the start and end of the cut must be extremely small; otherwise, the cut will be crooked or uneven. Customers typically require an accuracy within ±0.2mm. Furthermore, when cutting square tubes, the laser head must rotate around the tube once, requiring automatic Z-axis height adjustment. These actions put a strain on the controller’s interpolation and response speed.
2. Solution Configuration
Samkoon Technology’s core control solution for this type of online laser tube cutting machine includes the following hardware:
Part 1
Main Control PLC: PRO-C16X16T+ module, responsible for logic operations, motion control, and data interaction.
Part 2
Analog Input Expansion: PRO-E4AO, used to output analog signals, such as controlling laser power or height adjustment.
Part 3
HMI: SK-102QS-G touchscreen, allowing operators to set parameters such as tube length, speed, and cutting mode, and monitor the operating status in real time.
Part 4
Servo Drive System: Depending on the customer model, 4 to 6 R8 series servos are used to drive the feeding axis, tracking axis, rotary axis (for cutting square tubes), and Z-axis, respectively.
This solution adopts a partitioned subroutine structure, writing tracking synchronization, square tube cutting, and height following functions into different program blocks for easy debugging and maintenance. The HMI screen is also designed according to process logic, allowing operators to quickly learn how to use it.
3. Advantages of the Solution
(1) Smoother Synchronization and Less Mechanical Vibration
The tube cutting machine has a large inertia. If it starts too abruptly, the machine will vibrate violently, affecting the cutting quality. We added S-curve acceleration and deceleration to the control algorithm instead of simple linear acceleration. This makes the entire process from the tube being stationary to following the cutting speed very smooth, especially suitable for machines with large inertia.
(2) High Cutting Accuracy and Neat Cuts
By accurately calculating the positional relationship between the main axis (tube travel) and the slave axis (laser head movement) and adding feedforward control, the following error is effectively reduced. On-site measurements with calipers show that the cut position error is basically controlled within ±0.2mm, meeting the delivery requirements of stainless steel pipe manufacturers.
(3) Square Tube Cutting with Automatic Z-Axis Height Adjustment
When cutting square tubes, the distance from the tube surface to the laser head changes with the rotation angle. Our solution links the X-axis, B-axis rotation, and Z-axis height adjuster to maintain the laser head at the same height as the tube surface in real time, ensuring the cutting quality around the tube. For non-linear paths at the four corners, the program automatically breaks them down into multiple continuous interpolation segments to avoid pauses or overheating.
(4) Reduced Long-Term Production Costs
Compared to traditional sawing, laser pipe cutting eliminates the need for saw blades and coolant, resulting in lower electricity and maintenance costs. Although the initial investment is slightly higher, the savings in consumable costs are generally recovered within about a year.
(5) Strong Scalability and Support for Future Upgrades
The current solution supports a pipe-making speed of approximately 15 meters per minute. For future speed increases, an electronic cam function (a more advanced position synchronization method) can be enabled. Furthermore, we are planning to add processes such as online hole drilling, cutting arbitrary shapes, and cutting arc edges, which can be achieved simply by overlaying motion commands without replacing the entire control system.
(6) High Replicability and Suitable for Nationwide Promotion
This solution has already been put into actual production in a number of stainless steel pipe manufacturing plants with stable results. Due to the use of standardized PLC programs and HMI templates, equipment manufacturers can quickly replicate it to different models of online pipe cutting machines.
Samkoon Technology continues to provide motion control solutions for equipment used in pipe manufacturing, laser welding, and single-machine pipe cutting. For further information, please contact us!
