Wrinkling masters gr 3750

**paperpresspunch** · 09-23-2016

We just received a used riso gr3750 with a low print count. 90 percent of the masters we make are wrinkled in the same spot. Any advice or a contact for a Seattle, WA based tech would be greatly appreciated! Thanks.

Justin

**Iowatech** · 09-24-2016

Pictures, please? While it would be cool if we could, we cant see your machine or what it is doing. It would also probably be an awful invasion of privacy if we could see everything too, so maybe that's a good thing. While we're waiting, a few wild guesses, take them for what they are worth: First, make sure the plastic flanges are installed properly on the master roll. Also, make sure the master stocker area is clear of debris. And if you haven't tried already, install a new master roll. That's a pretty old machine, who knows how old the currently installed master roll is (and more importantly, what it has been through already)?

**paperpresspunch** · 09-25-2016

image.jpg image.jpg image.jpg image.jpg image.jpg
Here are a few photos. I'm not sure what would help see a possible problem. We replaced the master roll with a new one and we are still having the wrinkles. They appear on all of our drums. We did notice that when we press the master loading button the strip that gets cut isn't the same width on both sides as shown in the second photo. I also noticed that the plastic tabs located under the transparent cover where you remove the master strip are a bit beat up, and one of them is missing, as seen in the third photo. The last thing I would mention is that there is an audible wrinkling sort of sound during the master making cycle that I haven't heard when using my gr2710. I know they are different machines but I'm not too familiar with the differences. Anyway, any advice or ideas would be really appreciated!

Unrelated, the larger of the control screens is very dim. Is there any way to make it brighter?

Thanks!!!

Justin

**Iowatech** · 09-26-2016

Originally Posted by paperpresspunch

image.jpg image.jpg image.jpg image.jpg image.jpg Here are a few photos. I'm not sure what would help see a possible problem. We replaced the master roll with a new one and we are still having the wrinkles. They appear on all of our drums. We did notice that when we press the master loading button the strip that gets cut isn't the same width on both sides as shown in the second photo. I also noticed that the plastic tabs located under the transparent cover where you remove the master strip are a bit beat up, and one of them is missing, as seen in the third photo. The last thing I would mention is that there is an audible wrinkling sort of sound during the master making cycle that I haven't heard when using my gr2710. I know they are different machines but I'm not too familiar with the differences. Anyway, any advice or ideas would be really appreciated! Unrelated, the larger of the control screens is very dim. Is there any way to make it brighter? Thanks!!! Justin

Thanks for the pictures! There should be a green plastic flange on the right hand side of the master roll, but the fourth picture makes it unclear if it is installed. If it actually is not, that would definitely cause the uneven dimensions of the cut master strip and wrinkling. If you have an extra green flange for your GR2710, it will work perfectly in the GR3750. The main difference between the GR2710 and the GR3750 is that the 2710 can only print on letter and legal sized paper, but the 3750 can print on up to ledger sized paper. You can't swap the drums or the TPH or master material or stuff like that, but all the mechanical adjustments are the same, and most of the electronic ones are too. There's no adjustment for the brightness of the display, so you might be out of luck there. I suppose you might try a basic memory clear to see if that helps. If you are familiar with service mode, run code 90. Otherwise, hold down the "Reset" button on the very right hand side of the control panel while turning the machine on, and continue to hold the button down for a while (probably for 5-10 seconds, I always just listened to the initializing motors and released the button when their sounds got quieter). The plastic tabs in the clamp area assist with the master being removed from the drum. You'll probably have a master removal jam every once in a while thanks to them being damaged. You might want to clean the underside of the clamp sometime, it looks like it has a lot of ink on it. Sorry for the wall of text, my current internet connection is "Plan B". Once I get my primary internet connection restored, I'll at least be able to construct proper paragraphs.

**paperpresspunch** · 09-26-2016

Originally Posted by Iowatech

Thanks for the pictures! There should be a green plastic flange on the right hand side of the master roll, but the fourth picture makes it unclear if it is installed. If it actually is not, that would definitely cause the uneven dimensions of the cut master strip and wrinkling. If you have an extra green flange for your GR2710, it will work perfectly in the GR3750. The main difference between the GR2710 and the GR3750 is that the 2710 can only print on letter and legal sized paper, but the 3750 can print on up to ledger sized paper. You can't swap the drums or the TPH or master material or stuff like that, but all the mechanical adjustments are the same, and most of the electronic ones are too. There's no adjustment for the brightness of the display, so you might be out of luck there. I suppose you might try a basic memory clear to see if that helps. If you are familiar with service mode, run code 90. Otherwise, hold down the "Reset" button on the very right hand side of the control panel while turning the machine on, and continue to hold the button down for a while (probably for 5-10 seconds, I always just listened to the initializing motors and released the button when their sounds got quieter). The plastic tabs in the clamp area assist with the master being removed from the drum. You'll probably have a master removal jam every once in a while thanks to them being damaged. You might want to clean the underside of the clamp sometime, it looks like it has a lot of ink on it. Sorry for the wall of text, my current internet connection is "Plan B". Once I get my primary internet connection restored, I'll at least be able to construct proper paragraphs.

Thanks for the response!

The flange is installed, though ours is blue. I might try switching it with the our 2710 and see how that works but I'm guessing it's the same.

**paperpresspunch** · 09-26-2016

let me know if there are any pictures that would be more helpful.

**paperpresspunch** · 09-27-2016

I've just noticed that the other black roller in the master making unit, not the write roller but the black roller closest to the master roll, doesn't move when the masters are being made. Should it be rolling freely as the write roller pulls the masters? Could that be causing the wrinkles?

**Iowatech** · 09-27-2016

Originally Posted by paperpresspunch

I've just noticed that the other black roller in the master making unit, not the write roller but the black roller closest to the master roll, doesn't move when the masters are being made. Should it be rolling freely as the write roller pulls the masters? Could that be causing the wrinkles?

Um, it would be really useful if you could share a picture of the master making area with the roller you are talking about indicated, and a picture of the way you were able to see the roller not turning during the master making process. I just want to be absolutely sure of what is actually going on, because if what I'm thinking right now is actually happening, it will lead down a somewhat different path, but if I'm wrong that path will lead only to frustration. And an awful waste of time, too.

**paperpresspunch** · 09-28-2016

image.jpg image.jpgThe roller I'm talking about is the black roller directly above the master roll. I can see that it isn't moving when the machine is making a master. Should it be rolling as the master feeds?

Thanks for taking the time to look at these!

**gillje** · 09-28-2016

It might not work for you, but I used to have a gr3770 with this same problem. The only way I could figure to get around it was to manually apply pressure to the flanges as the master roll was turning to feed the master onto the drum. That usually did the trick for me.