Heidelberg Prosetter74 making hair lines in halftone screens and solids

[rbruce63]

The Heidelberg dealer in Costa Rica has not been able to pinpoint the culprits of our Heidelberg Prosetter 74 making hair lines in both halftones and solids. These hairlines appear in different parts of the plate pointing to a mechanical failure, as they repeat at the beginning of the plate and towards the middle section. However, specially noticeable in the halftone screens and the solids.

The Heidelberg dealer bas pointed to three parts but cannot provide them unless we pre-pay for these parts. There is no return policy for such parts:

P-Image Forming Card P/N PP057.38229 or 00.785.0922
P-P3C2
Laser Diode 30mW P/N PR.599.8190/02

We performed ourselves a cleaning of the mirror assembly, lubricated the never-ending screw, etc. The hairlines have diminished in size, however, they keep appearing.

The power supply was replaced on January as they don't last over 24 months (despite the fact that we have installed a bank of capacitors at the electricity entry point, a voltage regulator and the UPS with voltage regulator)

We would like to keep the Prosetter 74 and go to Azura Vi low-chem plates if and when they are available in Costa Rica or even Fuji's if the 30 mW laser can expose them. So far the LAP-V plates are still available and will be available for the next year!

There are used parts in the market now at a fraction of the cost of "new" Heidelberg parts.

Can you help pinpoint to what is causing the hairlines? Have you encountered hairlines occurring every few millimeters in parts of the plate specially on halftones and solids?

Regards,

Robert H. Bruce
San José, Costa Rica

 

[topdot]

Hi,

We can help you to check this. Can we be online at 3 PM or 4 PM Miami time?

My email is [email protected] and my phone number is 001(786)387-2588

Best regards,

Ricardo Bellizzi

 

[rbruce63]

Hi Ricardo:

Yes i will be available a 4:00 PM EST!

By the way all the updates to the software were made, etc. We considered the new power supply as part of the culprits as the laser is beaming to cause these lines, perhaps it is some stray current out of the capacitors, but we cannot test nor have any electrical wiring diagrams nor any are supplied by Heidelberg.

Regards,

Robert H. Bruce

 

[rbruce63]

Ricardo:

It seems that the hairlines accompany the image. They do happen in the same place in the same plate size: The C, M, Y, K plates have the hairlines in the same place.

But when we change plate sizes, the hair lines change position: If we put the GTOF 52 plate on top of the Speedmaster 72 plate using the punches to align the plates from entry to exit, the hairlines are in different places.

Therefore, the hairlines follow the image being engraved on the plates.

Another thing, the image on the Metashooter does not contain the hairlines!

 

[VladCanada]

It's unclear what direction of these hairlines: Fast Scan or Slow Scan.

 

[rbruce63]

VladCanada: I do not understand what fast and slow scan is. The hairline marks are in the same direction of the rotation of the laser.

They are perpendicular to the image on the AROUND side of the plate. If a plate is 52 X 72 the marks are perpendicular to the 72 cm base and parallel to the 52 side of the plate. They are separated by 7 cm each on both plates (24 X 52 and 52 X 72).

The hairlines seem to follow the images being engraved on the plate. They occur always on the first "signatures" on a two signature plate and on a four up signature plate, they appear on the second set of signatures.

The hairlines are always following the image and register on all the colors of a same size plate. However, if you align a 24 X 52 cm plate by the central punch to a 52 X 74 cm plate, then the hairlines occur in different areas of the plate.

It seems more an electronic problem than a mechanical problem.

The Heidelberg tech said to buy the P-Image card first, then the laser or the mirror and then the P3C2 card. It seems like an expensive route even with used parts, since the upgrade route with Azura Vi plates is not clear yet (at least in Costa Rica).

 

[VladCanada]

Yes, it is NOT a mechanical problem caused by some imaging carriage movement. In that case I expect some hairlines to be regular but along/across the whole plate. In your examples just only some part of image is involved.
It looks like a data stack transmission has some interruptions at the end of the portion of information.
Unfortunately I have lack of experience with Heidelberg equipment.
BTW here is a Laser Spot Generatiom Module on my hand at my avatar, but AGFA made.

 

[rbruce63]

Yes, it is NOT a mechanical problem caused by some imaging carriage movement. In that case I expect some hairlines to be regular but along/across the whole plate. In your examples just only some part of image is involved.
It looks like a data stack transmission has some interruptions at the end of the portion of information.
Unfortunately I have lack of experience with Heidelberg equipment.

Hi, what you are saying applies to the P3C2 card called interface card between the Metashooter and the Plate Recorder and/or the P-Image card which makes the image on the plate!

How frustrating this diagnosis has been! On top of that is trying to extend the life of a machine at the end of its life due to plate discontinuation. In the mean time I'm outsourcing thermal plates, very sensitive to cleaners and can be used at least twice as the violet plates.

I would be willing to throw $1,500 to the damned machine but not $3,000 or $5,000 in case is the laser.

Who are we going to call? Bill Murray is past his prime, and this ghost is quite mean!

 

[BWI]

Hi,

I talked to my technician about this. His suggestion was that there may be something wrong with the computer. Have you tried defragging the hard drive? Also, check the interface cable connection. Otherwise, it may be the two boards that were mentioned, unfortunately. He does not believe that there would be anything with the laser, but have you run an exposure test?

I understand your frustration with the end of life on the Prosetter. Have you considered using traditional photopolymer plates, instead of moving to Azura Vi? In either case, they will both require a new processor. Also, the 30 mW laser is adequate for imaging traditional photopolymer.

Have you considered getting a thermal CTP for in house?

 

[cosmo]

i would say its the laser, ive seen it before on violet machines, or, just dust on the optics, can you check how many hours your laser has done?

 

[rbruce63]

¡New findings! The damned machine is not producing the hairlines any more on 24 X 52 cm plate. I have yet to see a 52 X 74 plate.

We have yet to perform a HD defragmentation.

 

[rbruce63]

Hi,

Have you considered using traditional photopolymer plates, instead of moving to Azura Vi? In either case, they will both require a new processor. Also, the 30 mW laser is adequate for imaging traditional photopolymer.

Have you considered getting a thermal CTP for in house?

Photo-polymer plates. Indeed we have considered photo-polymer plates on our Prosetter 74. However, we would have to sort out the plate bending system of our rotary presses for business forms printing.

Business Forms Plate BendingThe plate bending system can cut the polymer plates so we would have to buy a system to press the plates with heat instead of physical action.

Lines per Inch Do the photo-polymer plates yield at least 150 LPI?

Photo-polymer plate processingDo I have to scrape the Raptor 68? What kind of processing machine and chemicals are used for developing photopolymer plates?

Thanks for your input!

 

[BWI]

Photo-polymer plates. Indeed we have considered photo-polymer plates on our Prosetter 74. However, we would have to sort out the plate bending system of our rotary presses for business forms printing.

Business Forms Plate BendingThe plate bending system can cut the polymer plates so we would have to buy a system to press the plates with heat instead of physical action.

Lines per Inch Do the photo-polymer plates yield at least 150 LPI?

Photo-polymer plate processingDo I have to scrape the Raptor 68? What kind of processing machine and chemicals are used for developing photopolymer plates?

Thanks for your input!

We do not have any experience in plate bending, so unfortunately I cannot give you input there.

Looking at the the plates that we use internally for testing, they yield 200 LPI. I cannot speak for other plates, but if you talk to your local plate dealer they would be able to help.

A silver Raptor 68 would not work for processing traditional photopolymer plates, or chem-free photoploymer plates. You would need to get a photopolymer processor, or a violet chem free processor.

 

[rbruce63]

Thanks for your reply BWI! I will have to see who is going to offer the photo-polymer plates!

 

[Boneck]

We have a Suprasetter 74… had the same issues with "random" scratches being applied to the plates. Our issue was indeed a mechanical issue. Scratches could be seen on the backs of the plates that you could visibly see… you could not see the scratches to the images on the plates until you put ink to it… we did resolve this as a roller issue. If you can see the scratches on the backs of your plates and think you might have the same issue… let me know and I can try to pull the paperwork on what exactly was replaced to fix this problem… it was not a laser issue or power issue as your are expecting.

 

[francisco hernandez]

do you still have the machinee ?. im looking for one. Thanks.

 

[Ritchiec]

My 2cents worth.

1. Check the earth strap, add another earth strap.
2. Check you power, neutral to earth. I've had fluctuating voltage leaks from 0.5v to 6v which was enough to cause stupid random lines.
3. Change change the LDS cable/data cable from shooter to prosetter and move it away from any power cables.
4. My last option is change the Screening set on the RIP. I have had a corrupt screen set before. eg if you are running HQS screens then choose an IS Screen set and see what happens.

Regards
Colin