Duplo DC-618 Skewing In Machine

[Andres]

Hi everyone!

I've been having skew issues with our DC-618. The skew adjustment knob has not been helping, and it seems like the paper is being skewed while running through the machine. All of our rollers are clean and we just replaced our blade. After 4 million cuts, we finally needed it replaced, and I was hoping that would resolve this issue.

Does anybody have any ideas on how to fix this? It's mostly noticble with 24 up business cards with the last few cards looking really skewed.

 

[EdwardB]

how thick is your material? if it is light material, turn down the vacuum. That solved a bunch of feed issues I had

what all is coming out skewed? creasing? cuts across? cuts in both directions? Are all of your modules completely seated into the machine?

 

[Andres]

The skewing is most noticable on our 380gsm cardstock, but it does happen on our 270gsm paper, especially on 17x11 folding brochures.
I will still try to turn the vacuum down.

Creasing, as well as cuts in both ways are skewed. I've taken out and cleaned paper dust off all of the modules and they appear to be seated properly.

 

[EdwardB]

vacuum won't help on anything as heavy as 200 gsm or heavier... I found lowering only helped on 90gm or lighter

my guess is you have a module that isn't sitting all the way down inside, or you have a roller (or rollers) as your culprit
pins full seated and thumb nuts snug:

either one or more rollers aren't touching all the way across
roller bearing rider should be equal on both ends of roller:

or

the tension is different across one or more rollers
thumb screws should be equal in adjustment:

 

[EdwardB]

** side note. you've had your machine for quite some time, check that a module mounting surface isn't damaged (i.e. was it dropped?)

 

[Andres]

The module mounting surfaces do not seem to be damaged and they are seated correctly. It probably is something with the rollers. I adjusted the thumb screws to as equal tension as I am able to. How tight should this be? The other areas you've shown in the second image look even to me, but maybe I am not seeing it well enough.

 

[Pennypicher]

How many sheets are thru your machine? Im guessing rollers are worn as Ive seen before. Is it the whole sheet or just the last few cards?

 

[tngcas]

We had this issue and it ended up being that the rollers needed replaced. Our repair guy said basically over time the middle of your rollers gets compressed so that only the "outside" edges are holding onto the sheets as they run thru. This makes the middle of the sheets start "walking" as they get cut since nothing is really holding down the middle's anymore.

 

[Andres]

How many sheets are thru your machine? Im guessing rollers are worn as Ive seen before. Is it the whole sheet or just the last few cards?

The last few cards have the most amount of skew. The first couple that are cut look much better.

 

[Andres]

We had this issue and it ended up being that the rollers needed replaced. Our repair guy said basically over time the middle of your rollers gets compressed so that only the "outside" edges are holding onto the sheets as they run thru. This makes the middle of the sheets start "walking" as they get cut since nothing is really holding down the middle's anymore.

Do you remember how long your rollers lasted before having to be replaced? How much was it to get them replaced?

 

[Pennypicher]

think of it this way. the whole sheet is getting transported as 1 unit. when the last few rows are slit you now have 3? separate rows trying to move together towards the cutter. sometimes one or more of those separated rows lag behind causing bad cards.
if you have the soft gray rollers maybe 500K sheets or the black rollers maybe 750K. But remember the bottom rollers are slightly wearing too. I have heard some folks have much less counts and the rollers were at fault.

 

[tngcas]

Do you remember how long your rollers lasted before having to be replaced? How much was it to get them replaced?

Let me look and see. It was in the millions. We used that machine pretty hard and we didn't realize originally that we needed to be cleaning the rollers regularly so I think they wore out faster than if we had been really diligent about cleaning the toner off of them regularly. On the new rollers we've been cleaning them weekly.
Looked at our invoice. GWI charged us about $220 per roller and there were 9 of them so about $2k to replace all of them.

Cleaning the rollers didn't fix the walking problem for us but I'm going to put the procedures they gave us in case someone in the future needs to know how.

Cassie
-----------------------------------

Here is the protocol they sent us for DC-618 roller cleaning:
To clean paper dust and other buildup on these rollers, they recommended the following:

1. On the main machine touch panel, press the “button” with the 3 dots.
2. Press “Cleaning Mode” then the “Enter or Send” “button”.
3. Open the top cover and remove all the modules.
4. Using a clean, microfiber cloth, spray Windex with vinegar (sold as an all in one product) on the cloth, then wipe surfaces off all the rollers.
5. When you close the cover, the rollers automatically advance approximately 1/6th of a turn, giving you a new surface to clean.
6. Opening and closing the cover will advance the rollers
7. Once all the rollers have been cleaned with the Windex / vinegar product, use warm to hot water on a clean microfiber cloth, repeating the wiping and opening and closing the cover for the machine to advance to a new roller surface.
8. When finished with the warm / hot water, use about a 60% Isopropyl Alcohol on a clean microfiber cloth to finish cleaning the rollers.
9. Use the same opening and closing of the top cover, to advance the rollers to a new cleaning position.
10. Reinstall the modules, press the “escape” “button” on the panel and resume production.

 

[tngcas]

think of it this way. the whole sheet is getting transported as 1 unit. when the last few rows are slit you now have 3? separate rows trying to move together towards the cutter. sometimes one or more of those separated rows lag behind causing bad cards.
if you have the soft gray rollers maybe 500K sheets or the black rollers maybe 750K. But remember the bottom rollers are slightly wearing too. I have heard some folks have much less counts and the rollers were at fault.

Also since the rollers are on springs they only go "tight" on the outside edges. So if there is any bowing in the middle of the rollers then it will walk the middle.
For example 90% of our jobs we run thru are 12x18 sheets so that's where they rollers got compressed mostly. 11x17 sheets did not walk at all because the rollers were holding down that size evenly. 13x19 sheets walked badly because the middle of the rollers weren't touching the sheets at all.

 

[Andres]

Let me look and see. It was in the millions. We used that machine pretty hard and we didn't realize originally that we needed to be cleaning the rollers regularly so I think they wore out faster than if we had been really diligent about cleaning the toner off of them regularly. On the new rollers we've been cleaning them weekly.
Looked at our invoice. GWI charged us about $220 per roller and there were 9 of them so about $2k to replace all of them.

Cleaning the rollers didn't fix the walking problem for us but I'm going to put the procedures they gave us in case someone in the future needs to know how.

Cassie
-----------------------------------

Here is the protocol they sent us for DC-618 roller cleaning:
To clean paper dust and other buildup on these rollers, they recommended the following:

1. On the main machine touch panel, press the “button” with the 3 dots.
2. Press “Cleaning Mode” then the “Enter or Send” “button”.
3. Open the top cover and remove all the modules.
4. Using a clean, microfiber cloth, spray Windex with vinegar (sold as an all in one product) on the cloth, then wipe surfaces off all the rollers.
5. When you close the cover, the rollers automatically advance approximately 1/6th of a turn, giving you a new surface to clean.
6. Opening and closing the cover will advance the rollers
7. Once all the rollers have been cleaned with the Windex / vinegar product, use warm to hot water on a clean microfiber cloth, repeating the wiping and opening and closing the cover for the machine to advance to a new roller surface.
8. When finished with the warm / hot water, use about a 60% Isopropyl Alcohol on a clean microfiber cloth to finish cleaning the rollers.
9. Use the same opening and closing of the top cover, to advance the rollers to a new cleaning position.
10. Reinstall the modules, press the “escape” “button” on the panel and resume production.

This is really helpful, thank. you!

We are only at about 900k sheets, but I think flat spots in the rollers may have delevoped over time. I was not the print operator at my job when the machine was originally installed, so I was unaware of our Duplo having to stay on to constantly rotate the rollers when idle. The last operator did not let me know about this and did not tell me I had to clean the rollers either. Sucks, but at least I know better now.

 

[QwazST]

It’s the rollers, have seen this issue in the 646 model, rollers discontinued, expecting it soon in all our 618 models out that we take care of. Rumor is a replacement roller coming for the 618 but no bulletin yet. Duplo will not do anything until a ton of complaining. They consider the soft grey rollers as a consumable and can wear out in 70k plus runs. Don’t adjust your springs it won’t help it will get worse. Have them replaced.
Thanks.

 

[KimR]

This forum is so good! We have a 645, starting to see similar issues. I think I will start trouble shooting on Monday.

 

[DYP]

You can gain more life out of your rollers by wiping them with this.

 

[Pennypicher]

This forum is so good! We have a 645, starting to see similar issues. I think I will start trouble shooting on Monday.

I think 645 rollers are not available anymore. They had a plastic coating that would tear so they replaced on the 646 with the sponge rubber gray ones.

 

[Pennypicher]

It’s the rollers, have seen this issue in the 646 model, rollers discontinued, expecting it soon in all our 618 models out that we take care of. Rumor is a replacement roller coming for the 618 but no bulletin yet. Duplo will not do anything until a ton of complaining. They consider the soft grey rollers as a consumable and can wear out in 70k plus runs. Don’t adjust your springs it won’t help it will get worse. Have them replaced.
Thanks.

646 has the new black rollers out. Not 100% smooth but a bit tacky. Hopefully last longer than the gray ones.

 

[QwazST]

646 has the new black rollers out. Not 100% smooth but a bit tacky. Hopefully last longer than the gray ones.

Yes, I’ve rebuilt nine machines with these rollers that are updated. They’re like the old 645 rollers but a little bit different material. Should be back to 1,000,000+ lifespan.