Riso FR 3950 UI - "Paper Jam Error" with no Jamming

[Safety_Man]

Hello everyone,

I recently purchased a used Risograph FR3950UI.

After getting it set up and turning it on, the display prompted me to hit the start button. Upon doing so, there was a loud banging very similar in description to this post from a couple years ago. I was able to pull out the drum and remove the master by pressing the two buttons, "Line/Photo" and "Master/Print", while I powered the machine on and then pressing the green drum unlock button.

I am very happy to report that the drum is now making and properly affixing new masters. Unfortunately, after the first print, which is halfway off the page and ghosting heavily, it shows a "Paper Jam" error despite spitting the paper out on the other end.

I've been doing some research and it sounds like it might be something having to do with the timing? Can anyone explain this further or point me to a resource that I can reference?

This is my first Risograph machine and I am very excited about the prospect of producing my comics so cheaply. I apologize if this is a common problem that's answered every week. I tried searching for the FR3950UI and never found a definitive solution.

Thanks in advance!

[Safety_Man]

Re: Riso FR 3950 UI - "Paper Jam Error" with no Jamming

Also, here is an example of what my prints are looking like after 20 or so, the original, and the error message.

[Iowatech]

Re: Riso FR 3950 UI - "Paper Jam Error" with no Jamming

It does sound like the timing.
I've posted about timing the older Risos a number of times, but I must have wiped that out of my posting history a long time ago, so for what it is worth here's something that should be useful:

FR timing.pdf
FR timing 2.pdf

(They show the P disk used in the GR line but are not on the FR machines, so you can ignore those.)

There are a lot of sharp edges and strong springs in that area that will harm people that are not paying attention though, so be careful.
However, before you do the timing adjustment, you might want to do some troubleshooting to see why the machine is out of time. If I was troubleshooting your machine, based on the information you have provided so far I would first make sure the master clamp on the drum was not bent, and I'd also make sure that it could move throughout its entire range without binding.
Good luck!

[Safety_Man]

Re: Riso FR 3950 UI - "Paper Jam Error" with no Jamming

It does sound like the timing.
I've posted about timing the older Risos a number of times, but I must have wiped that out of my posting history a long time ago, so for what it is worth here's something that should be useful:

[ATTACH]34795[/ATTACH]
[ATTACH]34796[/ATTACH]

(They show the P disk used in the GR line but are not on the FR machines, so you can ignore those.)

There are a lot of sharp edges and strong springs in that area that will harm people that are not paying attention though, so be careful.
However, before you do the timing adjustment, you might want to do some troubleshooting to see why the machine is out of time. If I was troubleshooting your machine, based on the information you have provided so far I would first make sure the master clamp on the drum was not bent, and I'd also make sure that it could move throughout its entire range without binding.
Good luck!

Hey IowaTech,

Thank you so much for the thorough reply and word of caution. Much appreciated.

Just to clarify, when people refer to timing, are they talking about the overall timing of the coordination of the different parts of the machine?

I'll certainly take a look at the master clamp on the drum first and check to make sure it spins the full 360 degrees. I was worried that something may have been damaged when I heard the intense banging as I initially turned it on.

Just to help me understand, is there a specific part of the master clamp that you think it could be? I found this image in a tech manual for the machine.
Screen Shot 2016-11-17 at 8.45.07 PM.jpg

I also found these pages for trouble shooting paper jams. Do you think any of these might be causing this issue?

Thanks again, IowaTech.

[Iowatech]

Re: Riso FR 3950 UI - "Paper Jam Error" with no Jamming

Just to help me understand, is there a specific part of the master clamp that you think it could be? I found this image in a tech manual for the machine.
[ATTACH=CONFIG]34797[/ATTACH]

I also found these pages for trouble shooting paper jams. Do you think any of these might be causing this issue?

That picture is pretty small, but I think if you look at the drum where letter "G" is you'll see the clamp hinge goes through a black metal piece. For master clamps that don't rotate smoothly, I usually found that was the most likely culprit, and a drop of penetrating oil usually took care of the problem.
When you get the back off of your machine (make sure to unplug the machine before you do), you will see that there are two cams that are driven by a timing (toothed) belt that is really tight, and that is what determines the overall timing. If the drum is prevented from rotating, that causes that belt to slip a few teeth on the drive pulley for the left hand cam and will cause some really scary noises and ridiculous margin problems. It is more efficient to adjust the right hand cam to solve that problem, so that is why the adjustment is the way it is.
You might want to hold on to those jam pages as they are pretty good, but I have never seen that cause the problem you have described.

[Safety_Man]

Re: Riso FR 3950 UI - "Paper Jam Error" with no Jamming

That picture is pretty small, but I think if you look at the drum where letter "G" is you'll see the clamp hinge goes through a black metal piece. For master clamps that don't rotate smoothly, I usually found that was the most likely culprit, and a drop of penetrating oil usually took care of the problem.
When you get the back off of your machine (make sure to unplug the machine before you do), you will see that there are two cams that are driven by a timing (toothed) belt that is really tight, and that is what determines the overall timing. If the drum is prevented from rotating, that causes that belt to slip a few teeth on the drive pulley for the left hand cam and will cause some really scary noises and ridiculous margin problems. It is more efficient to adjust the right hand cam to solve that problem, so that is why the adjustment is the way it is.
You might want to hold on to those jam pages as they are pretty good, but I have never seen that cause the problem you have described.

Thanks Iowatech for the help. I hired a technician and he was able to fix both issues.

You ended up being right about the belt slipping. The banging sound was from the teeth on the belt skipping on its cog. There was a very old master on the drum when I bought it. The master sheet refused to release when the machine tried to remove it to create a new one, and BANG BANG BANG! Timing was thrown off. Readjusting the belt manually tooth by tooth and a little trial and error had it printing correctly again.

As for the paper jamming... That was fixed with a new stripper pad. The old one had worn down and wasn't properly grabbing the paper.

I wanted to follow up on this for anyone who runs into similar issues in the future.