What is the reason for the difference in distance between the cylinder holder and the blank cylinder

[ali 120]

I have a GTO 52 printing machine, model 1997. At the end of the working day, I measure the blanket cylinder to the plate cylinder using a 0.10 mm feeler gauge, and the gauge goes in and out with slight resistance.
But when I check again the next morning, I find that the distance between the cylinders has decreased a lot, and I can no longer insert the 0.10 mm feeler gauge between them.
What is the reason for this?

 

[Jack liston]

Do you have air in machine when you check

 

[junker1984]

Have you checked in varying areas of the bearers?

 

[Raf77]

Do you have air in machine when you check

On GTO?

 

[ali 120]

Have you checked in varying areas of the bearers?

yas

 

[junker1984]

If that’s the case, you should have bearer pressures reset, and while in the process, examine cylinder bearings. No easy project for either of the steps mentioned.

 

[Adil]

Hi sir , please dont do anything
What you are observing is a common mechanical behavior on older offset presses, especially the Heidelberg GTO series.
You set the blanket to plate cylinder gap in the evening (0.10 mm with slight resistance), but the next morning the gap has shrunk, and the gauge no longer passes.

This happens mainly due to mechanical relaxation and thermal contraction.
During the working day The press is warm (bearings, cylinders, side frames).
Steel expands slightly with heat.
This creates a slightly larger cylinder gap.
But overnight The machine cools down completely. And Steel contracts.
The cylinder gap naturally becomes smaller.
On a GTO 52, a temperature change of only 5–8°C can reduce the cylinder gap by 0.02–0.06 mm, enough to block a 0.10 mm feeler gauge.

 

[junker1984]

Reasoning is all well and good, but what brings the question? Have you experienced print issues, this being the reason you are measuring the gap between plate and blanket bearers?

 

[Adil]

In this case, there may be a slight weakness in the print quality, but not an exaggerated one.