image area expanding on the plate

[lyzan]

Hi,

I am having another problem with our Galileo VXT. Even the service engineers from our supplier are having a hard time fixing our/my problem.

The image area on the plates are expanding by max of 2mm causing misregistration in the press. The expansion is along the width of the plate (long side).

Any ideas what causing this problem?

TIA,
Lyzan

[gordo]

Does your FTP have temperature compensation? If not the problem could be the ambient temperature.

Best gordo

[Armya Inc]

Hi,

I am having another problem with our Galileo VXT. Even the service engineers from our supplier are having a hard time fixing our/my problem.

The image area on the plates are expanding by max of 2mm causing misregistration in the press. The expansion is along the width of the plate (long side).

Any ideas what causing this problem?

TIA,
Lyzan

Hi, Expanding means stretching or misalignment along the slow scan?If you send a 4 colors job how many plates out of 4 are misregistered? I also would like to know the serial number of your machine.

[lyzan]

@gordo,

I have not heard any temperature compensation from the the service engineer for Agfa Galileo VXT.

@Armya

Image is stretching. For example if I have an imposition of 50 x 70cm (plate size is 1030 x 785mm), the imposition will become 50 x 70.2cm on two plates, then 50 x 70.1 on one plate, and 50 x 70.15 on another. Sometimes I will get identical stretch sized, but when run in the press the image especially on 2-3 colors text is misregistered. I'm not sure with the serial number, but on the label serial written is 51708.

Lyzan

[Armya Inc]

@gordo,

I have not heard any temperature compensation from the the service engineer for Agfa Galileo VXT.

@Armya

Image is stretching. For example if I have an imposition of 50 x 70cm (plate size is 1030 x 785mm), the imposition will become 50 x 70.2cm on two plates, then 50 x 70.1 on one plate, and 50 x 70.15 on another. Sometimes I will get identical stretch sized, but when run in the press the image especially on 2-3 colors text is misregistered. I'm not sure with the serial number, but on the label serial written is 51708.

Lyzan

Start with small solutions and remedies.
This is what I suggest to do first:
Measure the distance between the plate stop blocks on the plate punch that will be used. If multiple plate punches are used, measure distance for each plate size accordingly.Use exact measurement between plate stops to maintain exact registration.Do you know how to do this? It is from middle to middle.
The Galileo 3-point registration system using the adjustable electromechanical pins and the
plate edge detector, maintaining a triangular configuration. External plate punching system must match Galileo registration system exactly.
Using the 20%-80% method can cause misregistration.If unable to make exact measure, the 20%-80% method will have to be used with its limitations.
1-Launch Galileo OCT.
Open the attached file.
2-Select Plate Information Icon or pull down window.
3-Under Pin Position, Distance between pins, enter the premeasured distance between the plate stops and apply. Do this for each plate size.


Hope this will help!

[VladCanada]

Using the 20%-80% method can cause misregistration like plate (image) skew, but not image area expanding on the plate

[gordo]

Using the 20%-80% method can cause misregistration like plate (image) skew, but not image area expanding on the plate

A lack of temperature compensation when ambient conditions change can effect the size of the image on plate can't it?

gordo

[VladCanada]

A massive metallic drum of Galileo can't change its temperature so fast (dramatically) for 1 page-4 color CMYK to output sequentially and to get the misregistration.
Yeah, the first and the sixteenth plates could be different in size, if room is warming up in the morning for a few hours.

[Ozkan Hangisi]

@gordo,

I have not heard any temperature compensation from the the service engineer for Agfa Galileo VXT.

@Armya

Image is stretching. For example if I have an imposition of 50 x 70cm (plate size is 1030 x 785mm), the imposition will become 50 x 70.2cm on two plates, then 50 x 70.1 on one plate, and 50 x 70.15 on another. Sometimes I will get identical stretch sized, but when run in the press the image especially on 2-3 colors text is misregistered. I'm not sure with the serial number, but on the label serial written is 51708.

Lyzan

Hello Lyzan,

First; Isn't there a lenght calibration parameter in Agfa CtP ? I think your default expose is longer than original size in slowscan direction. Expose a geometry test and set the parameter correctly then you should measure 70 cm job as 70 cm on plate. not 70.2 cm

Second; When you measure a job shorter on plate, have you ever notice an exposure fault? I tought clutch which connects spindle and slowscan motor may got loose. In this case motor keeps turning but spinde might miss some steps. So the job would be shorter. But such a case you should see more or less visible thin lines on fastscan direction. If your jobs are just texts and shifting happens just on areas without images then you can't see any exposure problem.

I didn't work with Agfa CtP. These are just ideas without knowing machine. Hope they help

[VladCanada]

<<I tought clutch which connects spindle ... I didn't work with Agfa CtP. These are just ideas without knowing machine. Hope they help>>
AGFA Galileo CTP does not have any spindle to move the imager/carriage along a slow-scan.
Galileo has an Intelli-Track system (AGFA Avantra imagesetters have the same principle) - motorised carriage with digital and analog encoders to control the position and the speed.