[Jamming] GR3750 Paper catching on "hook lever"

[Guest]

Hello,

We own a used GR3750 risograph. When using the machine today the paper was getting stuck on the "hook lever" (I think it's called this, the red/orange spike inside the drum compartment). Each time I tried printing it would print, jam and when I opened up the machine the paper was wrapped around the level with the spike ripping a large tear in the paper.

Could anyone help us try and fix this problem?

Thank you,
Pigeon Print

[jermyth]

Re: GR3750 Paper catching on "hook lever"

It could be serveral things. First guess would be your print has a lot of coverage at the top of the page causing the paper to stick to the drum. The "seperation finger" is trying to remove the paper, but it's too stuck. 2nd the seperation finger has gotten miss aligned. 3rd the timing might be off. The first is the easiest to fix, make a new master with the original turned 180. The 2nd and 3rd I think if you look through older posts here you'll find one or two that has explained how to adjust (if you are handy with a screwdriver) the sep finger and timing better than I can. Good luck.

[PigeonPrint]

Re: GR3750 Paper catching on "hook lever"

We tried creating a new master, which worked, but then we discovered another problem: The "runners" (again we don't know the technical terms) aren't moving. We're assuming this is why the previous problem occured. Does anybody have any advice as to why this new problem might be happening and how to fix it?

[jermyth]

Re: GR3750 Paper catching on "hook lever"

By "runners" do you then the black "belts" the exit the paper from the machine? If they are not moving then either the exit one-way gear is shot or the belt that drives the gear pack has broken or the clutch on the gear pack for the exit belts is shot. Ussally it is the one-way gear. Not something a non-tech can replace, if you can even find that one-way anymore. GR parts are getting harder and harder to find. Riso quit making GR parts about 3 years ago.

[PigeonPrint]

Re: GR3750 runners not moving

Thanks so far, yeah the belt is not moving, need to go have a better look to work out what it is causing it. I've looked up "one-way gear" online and dont get any hits back apart from this thread. Does anyone have a part number for it? Found this site selling parts - Riso suppliers, Riso Supplies incl. RZ300, RZ200, RZ370, RG2500, RC4500, V8000 Looks like we need to get an engineer out.