What are the common faults and solutions of long measuring machines?

What are the common faults and solutions of long measuring machines?
1、 Preface
Long length cutting machines are commonly used for fixed length cutting of rolls such as films, paper, fabrics, plastic sheets, and metal foils. They have high work efficiency, accurate cutting, and easy operation, making them an indispensable key equipment in industries such as packaging printing, electronics, electronics, textiles, and advertising.
However, during long-term operation, it is inevitable that various malfunctions may occur with the long measuring machine. If these faults are not detected and dealt with in a timely manner, they will not only affect production efficiency and product quality, but may also lead to equipment damage or safety accidents in severe cases. Therefore, understanding the common types of faults in long measuring machines and mastering corresponding solutions is a fundamental skill for equipment operators and maintenance personnel.
This article will provide a detailed explanation of the operating principle, common fault phenomena, cause analysis, and solutions of the long length machine, providing reference for practical operation and maintenance.

2、 Common types of faults and solutions for long measuring machines
Fault 1: Inaccurate cutting length
[Fault phenomenon]
The length of the cut material is too short or too long;
The size of each cut is inconsistent, resulting in significant errors;
The cutting size varies randomly and is difficult to control.
Possible reasons
Encoder malfunction or loss of pulse signal;
Length setting parameter input error;
PLC program data exception;
Photoelectric sensor identifies positional deviation;
The traction wheel slips or wears, causing unstable feeding;
The material itself has elasticity and is affected by environmental temperature and humidity.
[Solution]
Check if the encoder is loose, damaged, or dirty, and replace it if necessary;
Re check and set length parameters;
Clear PLC cache data and restart the system;
Calibrate or adjust the installation position and sensitivity of photoelectric sensors;
Replace aging or worn traction wheels and adjust pressure;
If the material is prone to expansion and contraction, a compensation coefficient can be set or operated in a constant temperature environment.
Fault 2: The cutting blade cannot move or moves slowly
[Fault phenomenon]
Pressing the cutter button has no response;
Slow descent speed or incomplete downward pressure of the cutting blade;
The cutting blade is stuck halfway and cannot return to its original position.
Possible reasons
Electromagnetic valve malfunction, unable to control cylinder action;
Insufficient gas source pressure or pipeline leakage;
The cylinder itself is worn and stuck;
The cutter travel switch is damaged and failed to trigger the signal;
Poor circuit contact or interruption of control signal.
[Solution]
Replace or repair damaged solenoid valves;
Check the pressure gauge and adjust it to the required range of the equipment (such as 0.6-0.8MPa);
Check whether the gas pipeline is leaking or blocked, and repair it in a timely manner;
Replace damaged travel switches or sensors;
Check the electronic control board, relays, and wiring connections to eliminate circuit problems.
Fault 3: Unstable or stuck feeding
[Fault phenomenon]
The materials are sometimes fast and sometimes slow, with inconsistent rhythms;
The material deviates or folds during the traction process;
The material is stuck at the feed inlet or roller.
Possible reasons
Unstable operation or control failure of traction motor;
The traction wheel or rubber roller is severely worn and the clamping force is insufficient;
The material guiding system was not leveled, resulting in material deviation;
The photoelectric detection response lags behind;
The tension control system of the equipment is abnormal.
[Solution]
Check the operation status of the frequency converter and motor, whether they are overloaded or tripped;
Replace aging rubber rollers or increase traction wheel pressure;
Adjust the balance position of guide rollers, guide rails, and other parts;
Correct the position of the photoelectric detection and replace it with a more sensitive sensor if necessary;
Check if the tension controller and tension feedback device are sensitive and working properly.
Fault 4: Edge or unevenness of the incision
[Fault phenomenon]
Burrs and burrs appear on the cutting edge;
The incision is uneven, offset or wavy;
The edges of the material are burnt and powder falls off.
Possible reasons
The cutting blade is passivated or the angle is not appropriate;
The contact angle between the tool and the material is incorrect;
Insufficient cutting pressure;
The material is too soft or has static electricity, making it difficult to cut off;
Cutting speed too fast, unable to react.
[Solution]
Regularly replace blades to maintain sharpness;
Adjust the angle of the cutting blade to be perpendicular or at an appropriate angle to the angle of the material;
Increase the downward pressure or cutting time;
Perform electrostatic treatment on materials or use anti-static devices;
Reduce cutting speed and improve cutting stability.
Fault 5: Touch screen or control panel malfunction
[Fault phenomenon]
No response to touch operation;
Parameters cannot be entered or saved;
The screen is black, flickering, or garbled.
Possible reasons
Screen aging, moisture or damage;
Control program crashes or logic disorders;
Control board communication failure;
Unstable power supply and large voltage fluctuations;
Loose or damaged circuit connectors.
[Solution]
Replace damaged touch screens or cables;
Power off and restart the system to restore default settings;
Check the communication line between PLC and touch screen;
Use a regulated power supply to avoid voltage fluctuations;
Regularly check all control circuit connection points to ensure stability.
Fault 6: Automatic mode cannot be started or frequent alarms occur
[Fault phenomenon]
Auto run startup failed;
Automatically shut down after running for a period of time;
The screen frequently prompts alarm information and cannot be resolved.
Possible reasons
Starting position or sensor not triggered, system protection;
Parameter conflicts, such as length settings not matching speed;
A step in the automated process timed out or was interrupted;
The system mistakenly believes that the materials are exhausted;
Control logic error or main program damage.
[Solution]
Check if all starting and positioning sensors are triggered normally;
Recheck the parameter settings to ensure logical correctness;
Refer to the alarm code instructions and investigate each item one by one;
Ensure that the material is within the set sensing range;
If necessary, contact the equipment manufacturer for program updates or system recovery.

3、 Daily maintenance and prevention suggestions
The malfunction of a long measuring machine is often not a sudden occurrence, but the cumulative result of improper operation and maintenance of the equipment. In order to extend the service life of the equipment and reduce the failure rate, it is recommended to strengthen daily management from the following aspects:
Clean the equipment surface, guide rails, and tool parts once a day to avoid dust accumulation;
Check key components such as traction wheels, blades, sensors, and air pipes once a week for looseness or aging;
Regularly lubricate transmission components to maintain mechanical flexibility;
Set up a regulated power supply for the electronic control system and avoid humid and dusty environments;
Operators must hold certificates and be familiar with the operating procedures and emergency response methods;
Establish a ledger for equipment operation and maintenance, with records available for troubleshooting.

4、 Conclusion
As an essential cutting equipment in industrial production, the operation status of the long ruler machine directly affects production efficiency and product quality. Through the analysis in this article, we can see that common faults in long measuring machines are mainly concentrated in mechanical structure, electrical control, pneumatic system, and detection components. The key to solving these problems lies in early detection, early handling, re maintenance, and prevention.
Equipment is not afraid of use, it is afraid of not being maintained. By standardizing operations, regular inspections, and scientific maintenance, the failure rate can be significantly reduced, and the stability and reliability of equipment operation can be improved. I hope the content provided in this article can provide practical guidance for equipment managers and operators of various enterprises, helping to achieve safe and sustainable production goals.