Issues with roller marks/banding RA4 printing

CB_

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The Colex roller transport processor at the darkroom has started to give me issues - specifically roller marks and banding. I’ve noticed the issue almost exclusively on my Kodak papers (Endura, Royal). My Fuji paper (CA type II) is largely unaffected. I know the processor is set up with Fuji Digital RA pro chemicals (P1-R developer). I’ve attached a photo of an un-corrected test print to show it at its worst. What the hell is going on? I will add the first response was to take out and thoroughly wash the rollers. They’ve been washed at least a couple of time within the past week in attempts to rectify the issue.
 

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Wayne

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I'm just wild guessing, but are the rollers starting to swell and go bad? Can you take them out and inspect them for trueness or do a dry (or water) run while watching them to ensure they aren't warped leaving gaps between them?
 

foc

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I am not familiar with this processor but I guess it is a roller transport type.
Banding can be caused by the print slipping and not moving smoothly through the processor.
This may be caused by uneven rollers, swelling, or a faulty transport gear. (although the Fuji paper doesn't have this problem) Examine the great and check no chemical buildup on the teeth/cogs.
I would suggest that if you can, remove the developer rack/set of rollers, wash and then manually feed (turn the rollers by hand) a sheet of blank paper through the roller set and watch for any slippage.
Let us know how you get on.
 
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CB_

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Wayne said:
I'm just wild guessing, but are the rollers starting to swell and go bad? Can you take them out and inspect them for trueness or do a dry (or water) run while watching them to ensure they aren't warped leaving gaps between them?
Click to expand...

I think I'm going to do this - the lid of the processor is easily removable, so I'm going to feed some paper through the machine and see where it seems to have issues. Unfortunately given the age and lack of information on this machine, I'm getting the feeling I might be totally screwed if it is in fact the rollers that are causing the issue
 
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CB_

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Do you have any suggestions for cleaning the chemical buildup in the machine? I'm not able to find any service manuals online or from Colex, and while pretty DIY handy, I've never cleaned a machine like this before. The machine is supposedly self cleaning, but there definitely seems to be some sort of buildup in the dev tank. Doesn't seem like it's on the rollers but I will need to look into it and see if it is affecting the gearing at all.
 

koraks

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halfaman said:
I don't know Endura but Fuji CA type II has a thin base. If Endura base is thicker perhaps that explains why rollers affects it but Fuji CA don't .
Click to expand...
That's my first thought as well. Endura has a fairly heavy base, while CAII is quite flimsy in comparison. I can well imagine that degrading rollers present problems initially only with thinner papers. Probably the problem will become worse later on and also start to affect heavier papers.
 
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CB_

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Actually it's backwards - the problems are presenting themselves on the heavier, nicer papers, rendering them unusable while the CAII seems to just slip through totally fine.
 

foc

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If you can remove the dev tank rollers, gently lift them out and onto a large tray or basin. Be carefull as RA4 developer can make things slippy.
Then wash the roller unit down with tap water.
To clean the rollers I would suggest using a cloth dipped into methylated spirits/denatured alcohol and gently rub the rollers while turning them. If gears have a build up of gunk then use a large wooden tootpick to remove it. You could also use an old toothbrush but it can splatter dissolved black gunk all over the place if you are not careful.
Examine each roller. They should have no bulges and should lie flat and through to the next roller. If not then they need replacing.
I have my suspicions that there may be a bulging roller and that may be why the thinner paper is not affected.
If you can upload any photos of the rollers all the better.
 

koraks

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Chandler said:
Actually it's backwards - the problems are presenting themselves on the heavier, nicer papers, rendering them unusable while the CAII seems to just slip through totally fine.
Click to expand...
Still, paper thickness seems to be a possible factor. If I were you I'd inspect those rollers closely and pay particular attention to how they are spaced, and if there's some kind of mechanism that ensures proper alignment of the rollers against each other.

And please stop posting the same question in every subforum you come across; it's annoying.
 
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