KM Pro 951 Output Irregularity

[Ynot_UK]

Our Pro951 has a PF-706 paper deck and FS-532 finisher. Printing on A3 80GSM Navigator - the same substrate we always use and run circa 80k sides each month. All new wraps opened & loaded today, from the same pallet of paper. The job is output to the main tray, with no finishing, no offsetting - just regular stacking.

Today, the machine has started outputting this sequence:
2 sheets with an upward curl just to the front of the leading edge, followed by 3 good sheets, another 2 curled, 3 good, 2 curled, 3 good, etc...
We have the substrate in trays 3 & 4 for continuous operation. This is only happening when taking substrate from Tray 3. When it is using Tray 4 the problem is not happening.

Any engine related thoughts (fuser temp, belt charge, etc.) seem to be barking up the wrong tree, as if they were causal then the problem would be seen when pulling substrate from either tray. Registration is perfect from either tray, tyres changed but the problem persists.

Any thoughts welcomed...

 

[kslight]

I don’t know that machine, but my immediate thoughts are different paper drawers feed a different direction. What happens if you flip the paper in tray 3 over?

 

[Ynot_UK]

I don’t know that machine, but my immediate thoughts are different paper drawers feed a different direction. What happens if you flip the paper in tray 3 over?

Thanks, we did try that and it makes no difference.

 

[bill kahny]

is the bad drawer defined as thinner paper or lighter GSM?

 

[Ynot_UK]

is the bad drawer defined as thinner paper or lighter GSM?

No Bill, paper catalogue the same on both drawers.

 

[jwheeler]

First thought would be if the paper manfuacturer gave you the opposite grain direction.

Beyond that, even with the same paper profile, you can have some adjustments be different. I don't have a 951 to check if it has the same settings, but we did have 1250's and now 6136's. If you click on the paper settings, then select the drawer, then "Change Set"...do you see "curl adjustment" toward the bottom left of the screen? If so, try changing that. If not, you can adjust the pressure from the fuser roller for that drawer specifically. Click on paper settings, select the drawer in question, the select "Change Set", then "Expert Adjust". Click next a few times until you see "Pressure Power Setting". Try changing that to "Weak" or "Very Weak".

 

[Ynot_UK]

@jwheeler -our tech spent four hours this morning stripping down and cleaning the paper deck and engine fully through. This seems to have resolved the issue. I think some of those options above don't exist on the Pro951 driver, which is quite old and I'm aware different to the 1100 driver, from when we looked at it a while back. Thanks as always all the same.

 

[jwheeler]

@jwheeler -our tech spent four hours this morning stripping down and cleaning the paper deck and engine fully through. This seems to have resolved the issue. I think some of those options above don't exist on the Pro951 driver, which is quite old and I'm aware different to the 1100 driver, from when we looked at it a while back. Thanks as always all the same.

Got it. Glad the tech got it resolved. And just a note...those instructions were not within the print driver, they are on the touch screen of the machine.

 

[TicketsandBadges.com]

Got it. Glad the tech got it resolved. And just a note...those instructions were not within the print driver, they are on the touch screen of the machine.

I have a 951, 3070, 3080. To my knowledge you only get the curl adjustment if you have a relay unit. I have them on my color machines but not on my B&W 951. If he had a relay unit then it would show up on the screen as an option.

 

[Ynot_UK]

I have a 951, 3070, 3080. To my knowledge you only get the curl adjustment if you have a relay unit. I have them on my color machines but not on my B&W 951. If he had a relay unit then it would show up on the screen as an option.

That makes sense, as we don’t have those options on our Pro951.
Maybe wrong, I believe you can add an RU-509 to the Pro951, although this isn’t shown on the specs as an option. I saw this configuration on one for sale a while ago.