GR 3750 leaving ink line down the middle of prints

[ion]

Hi!

I am having an issue with my GR3750 leaving an ink line down the middle of each print (see the following picture).

IMG_4183.JPG

After some investigation, it looks like there is a plastic red needle piece that is ripping the master and getting ink on it which is leaving the ink streak on the paper. The red needle is connected to a bar where the paper exits the drum area.

I took the back off of the riso and it seems like there is a rubber belt that is interfering with a wheel and arm that are connected to the bar with the attached red needle, and it might be causing the red needle to jam into the drum too far. Here are pictures of the arm, wheel, and belt from different angles.

IMG_4184.JPGIMG_4185.JPGIMG_4186.JPG

I'm wondering if anyone knows of an adjustment that I can make to fix this. Should the belt rest directly on the top of the rubber wheel connected to the arm? It looks like it should.

I would appreciate any help. Thanks so much!

[Iowatech]

Re: GR 3750 leaving ink line down the middle of prints

I'm wondering if anyone knows of an adjustment that I can make to fix this. Should the belt rest directly on the top of the rubber wheel connected to the arm? It looks like it should.

I would appreciate any help. Thanks so much!

That wheel should not contact that belt, it is supposed to contact the cam on the back of the drum to move the picker finger (red plastic needle) away from the drum when the clamp is passing by.
The bracket that wheel is attached to is either bent or broken. Hopefully just bent, as then you can bend it back into position. Just take the drum out of the machine, reach in to the drum cavity and pull the metal piece the roller is attached to towards you a little bit.
Good luck!

[ion]

Re: GR 3750 leaving ink line down the middle of prints

That wheel should not contact that belt, it is supposed to contact the cam on the back of the drum to move the picker finger (red plastic needle) away from the drum when the clamp is passing by.
The bracket that wheel is attached to is either bent or broken. Hopefully just bent, as then you can bend it back into position. Just take the drum out of the machine, reach in to the drum cavity and pull the metal piece the roller is attached to towards you a little bit.
Good luck!

Thanks so much! That makes perfect sense because the bracket the wheel is attached to looks to be bent towards the back of the machine causing it to interfere with the belt. I will bend it back and hopefully we are golden

[filmplane]

Re: GR 3750 leaving ink line down the middle of prints

Thanks so much! That makes perfect sense because the bracket the wheel is attached to looks to be bent towards the back of the machine causing it to interfere with the belt. I will bend it back and hopefully we are golden

Did you resolve this issue? I have this same issue when the Tensioner Bracket Pulley slips - Its that little triangular bracket that has a pulley that the belt in your picture sits on. In your photos, you can see the tension bracket pulley in the last photo lower right of the frame.

That tensioner pulley as Iowatech helped me discover are prone to wear out, and the belt slips off, causing all kinds of issues including the line on your prints.

I had to take mine to a machine shop to resolve the issue of the pulley slipping off the bracket. Just thought I would share in case issue is still happening. Good Luck!

[ion]

Re: GR 3750 leaving ink line down the middle of prints

Did you resolve this issue? I have this same issue when the Tensioner Bracket Pulley slips - Its that little triangular bracket that has a pulley that the belt in your picture sits on. In your photos, you can see the tension bracket pulley in the last photo lower right of the frame.

That tensioner pulley as Iowatech helped me discover are prone to wear out, and the belt slips off, causing all kinds of issues including the line on your prints.

I had to take mine to a machine shop to resolve the issue of the pulley slipping off the bracket. Just thought I would share in case issue is still happening. Good Luck!

Yes! The issue seems to be resolved. Thanks for the additional information!