col variation

[edwardraj a]

we have sm102,recently we are facing below problem which make more complicated to produce quality product.

Col variation in every 10 sheets,that major colors are cyan and majenta.

kindly help me to get out of this

 

[Ret Heidelberg Instructor]

It could be anything. You need to provide more information about your problem.

 

[Ajax]

I would go watch your ink fountain roller. Sometimes they don't ratchet correctly. They'll move at a smooth 50% and suddenly drop to 30% or plus to 90%. Had that happen in my magenta unit on an mofl. Every operator on couldn't figure why we were all chasing color in that unit until I went up and noticed the ductor speed wide open and shutting down on its own.

Just something to check.

 

[Al Ferrari]

So what did you do to correct this ductor roller speed variation on that unit?

Al

 

[Ajax]

As it was a five color I moved three colors back a unit (KCM-Y) until Heidelberg arrived. My company refused to fix equipment in house that was still under warranty. As for the outcome I couldn't tell you much. It was a 24/7 shift so it's fix was when I wasn't there. Anyway, I was just offering a some advice as to a similar if not the same problem. Story short, once Heide came problem was solved.

 

[Mike Herndon]

So what did you do to correct this ductor roller speed variation on that unit?

Al

On SM102 and some other models there is Heidelberg Service Bulletin on this. A few things to check:

1- The over-run clutch attached to the end of the fountain roller on the operator side is slipping. You can see this easily while the press is running

2- Open the OS side cover, you will see the over-run clutch attached to the fountain ball. A actuating arm is attached to the over-run clutch and to the gear box that control the ink sweep adjustment. On the top of the box is white plastic gear attached the ink sweep motor. This gear rotates againts a smaller steal gear attached to the adjusting spindle. The small flat bearings on the top and bottom of spindle shaft can get out of tolerance, it's not that they wear out but instead the spindle develops play over time. The play allows the weight of the arm to move down as the press runs changing your ink sweep setting. The bearings need to be re-shimed to tighten up the clearance. An easy way to check for this is mark one of the teeth on the ink sweep motor gear and see if it moves on its own while running.

To re-shim the bearings the whole assembly has to come out. Instead, what Heidelberg does is place a clamp on the top of the spindle to create enough resistance to keep the arm from dropping on its own.

3- Last thing to check is the ductor roller settings, the top distributor roller settings (yellow roller to distributor), and the clutch on top distributor roller. If you can grab the top distributor(rislan) by hand and move it or it spins free the clutch under the drive side cover is bad. If the distributor clutch is bad you can have inconsistent color from ductor shock, the ink will tend to purge into the roller train.

These are all problems we've had to deal with on our SM102's.

I hope this helps.

Mike

 

[edwardraj a]

Mainly we suspect on the roller and water side.Its possible

 

[Ret Heidelberg Instructor]

If you suspect your problem is on the ink roller and dampening side, consider checking those settings first to see if they are within recommended in specification. If not then you will going around in circles, you are fighting the press, and the press is winning. I often saw a lot of problems in the field where rollers were not set and gave the operator fits. Consider when the problem started and ask yourself what has been happening over time. If you were printing fine for 2 weeks and then the trouble started try an pin point any changes that you suspect. It could be a mechanical problem also, but try to solve the problem one step at a time. Consider getting help from professionals and also from experienced operators.. This can save you time and money in the long run.

 

[bspillai78]

hai ed,
how much water you feed (%), what is the sequence

 

[edwardraj a]

Hi Water feed is more than 60

Sequence is black cyan majenta yellow.

 

[D Ink Man]

Mike Herndon has given the best reply and probable remedy for the problem.

He is excellent. Listen to him and follow what he says. He is D Press Man.

D Ink Man