In a paper converting plant, a few millimeters may not look like much.

But when the same error appears across a production run, it becomes a real problem.

The first sheets may be fine. Then, after the machine has been running for a while, 

the sheet length starts to change. You check the settings. Nothing has been changed. 

There is no obvious alarm. You adjust the cutting length, run the machine again, and everything looks normal.

For a few hours.

Then the problem comes back.

This is a situation many operators have seen.

And sometimes, the cutting setting is not the real problem.

Start with the length feedback

A sheeter depends on several systems working together. The paper has to be fed at the right speed, 

the actual web length has to be measured correctly, and the cutting system has to receive the right position signal.

One part that deserves attention is the encoder.

The encoder tells the control system how far the paper has travelled. If the encoder connection becomes loose 

or the encoder shaft slips slightly during long-term high-speed operation, the feedback may no longer match the 

actual paper movement.

The machine may still be running normally.

But the cutting length can slowly drift.

This kind of problem is easy to miss because there may be no alarm on the screen.

Don't forget the timing belt

The same applies to the synchronous belt in the feeding system.

A belt can look perfectly fine from the outside and still have changed after long-term operation.

Stretching, wear, or insufficient tension can affect the actual feeding distance. The control system may be 

giving the correct command, but the paper may not be moving exactly as expected.

That small difference can eventually show up as a few millimeters on the finished sheet.

So when checking a cutting problem, simply asking whether the belt is broken is not enough.

Its tension and condition also need to be checked.

Why does the problem sometimes come and go?

This is where things get more difficult.

If the machine cuts correctly at low speed but starts to drift at higher speed, or the problem appears only 

occasionally, the electrical side should also be considered.

Paper converting plants often have inverters, motors, and other high-power equipment operating nearby.

 Depending on the machine design and communication method, electrical interference can affect pulse or position signals.

The result can be an intermittent problem that is difficult to reproduce.

One day the machine runs normally.

The next day, the same settings produce a different result.

Paper tension can make a small problem bigger

The paper itself also matters.

Different paper grades and weights require different tension settings. If the tension is not properly matched to the 

current roll, the web may become too tight, too loose, or unstable during feeding.

When that happens, a small mechanical or signal error can become much more noticeable in the finished sheets.

This is why changing the cutting length alone does not always solve the problem.

The paper tension needs to be checked as well.

So, what should you check first?

When sheet length starts to drift, there is no need to immediately start replacing parts.

A simple step-by-step check is usually a better starting point.

First, check the settings and paper tension.

Make sure the cutting coefficient is correct and the tension is suitable for the current paper.

Then check the encoder and feeding system.

Look at the encoder connection and mechanical fixing. Check the synchronous belt for tension and wear.

If the problem keeps coming back, check the electrical signals.

Look at the wiring, communication method, and the surrounding electrical environment.

If a mechanical part is worn or has a structural problem, adjusting the cutting parameter will only hide the problem for a while.

A few millimeters can tell you something

The important question is not simply:

“How do I correct the 3 mm?”

It is:

“Why did the 3 mm appear in the first place?”

A paper sheeter is a complete system. Feeding, tension, length measurement, transmission, and cutting all affect the final sheet.

At CHM, our engineers look at the problem from the whole system rather than simply changing one number on the screen.

For operators, regular checks can also prevent many problems from becoming bigger ones:

Check encoder fixing.

Check belt tension and wear.

Recheck tension when changing paper grades.

And when the sheet size starts to drift, investigate early.

Because a few millimeters may be small on a single sheet.

Across thousands of sheets, they are not.

CHM Machinery
Precision in Every Sheet.