RISO GR3770 Clamp Error

[Jamool]

I am in the process of fixing a RISO GR3770 and have run into T3 and T14 error codes, which got me looking into the Clamp System.

I noticed a bent piece of thin metal attached to the clamp cam, that was blocking the drive gear. Does anyone know the correct orientation of this piece? What does it do?

Attached are a few images. Any help would be greatly appreciated.

Jameel


IMG_1950.jpgIMG_4077.jpgIMG_4078.jpg

[20gaugeO/U]

I don't remember ever running into that plate being bent but from the looks of it it may be nothing more than a grounding contact plate, looks like 1 screw so take it off and see. Doubt it was ever needed

[Jamool]

What is the procedure when reinstalling the motor? I am getting a T1 error and the clamp does not seem to lower. Do I need to do a memory reset of some sort? I noticed that the drive gear is a little loose on the cam, is this normal?

I am wondering if this is connected to the machine timing. My HD drum seems to lock into the machine perfectly, but my GR/FR drums need a little nudge to lock in.

Thanks for the response.

[20gaugeO/U]

Memory clear -- Turn machine off, hold yellow reset down while turning on the machine, release when beeping and normal sounds stop

The drive pin chuck on the back of the GR/FR drums are probably a little "off" from the key coming out of the back wall of the 3770 so that's probably why you need to nudge it in. Or the chuck in the black 3770 drum is cracked and over rotating, or the roll pin is cracked inside the key and has slop.

[Jamool]

Ok the motor is back in and memory is cleared.

When I try to make a master it seems that the gear is skipping over the gear on the drum and not flipping the clamp.

Any suggestions?

[20gaugeO/U]

First put a little oil in the clamp plate open/close gear area on the top of the drum, sometimes that part became gummed up.

Does the motor assy come down and make an attempt to flip over the clamp plate then Pop attempt pop attempt pop code failure??? I can't remember if the GR 3770 used the same clamp motor frame assy as every other GR in the line... if so there is a hairline crack in the L shaped piece that has a decent sized spring attached at 1 end. Have to take that assy back out and bend the L back square to compensate for the crack that has shortened the come down distance and weld or put a bead of liquid metal epoxy in that corner.

Good luck

[Jamool]

Any recommendations on a type of oil to use to lubricate the drum clamp gear area?

The clamp motor test is exactly as you describe. The clamp lowers and attempts to lift the clamp on the drum. It lifts slightly then fails and then tries to repeat until error code. Could it be hitting a part of the master making area? I have tried with different drums and it failed on all.

I was also wondering if I need a new drive gear. While it doesn’t appear to be missing any teeth, it is a little loose on the cam and only has 4 teeth. I have a donor GR3750 that I have compared the assembly with and that drive gear has many more teeth, but a smaller clamp and different mounting frame.

I will remove the unit today and inspect for any cracks.

Thanks

[Jamool]

I actually noticed from my original post images (first image with the assembly in the machine) that one of the teeth on the gear is indeed missing the tip and looks rough.

Do you think this gear from a GR3750 would work as a replacement? I have attached an image.

IMG_1951 (1).JPG

[20gaugeO/U]

Some light machine oil or WD-40 like stuff would be fine.
Yes the clamp plate on the drum may be hitting the black and clear plastic cover plates (the ones you lift to remove the cut strip). I don't remember how the 3770 looks but the smaller 1700's sat on a foam pad on a silver metal piece that you can remove with 2 small screws from the top. When the foam was shot I'd bend the metal up and remove the foam and sticky tape holding it in place. Made a little more noise when opening and closing the clamp plate but who cared with all the other noises the machine was making. That could be your problem.

Not sure about the gear assy. Haven't worked on a GR in close to 10 years probably...

[Jamool]

Thank so much for the response 20guage. I really appreciate the input.

I have gone ahead and removed the drive gear from my donor machine. I think I will give it a try.

Was it normal operation to hit the black plastic shield on the way up?