No. 4 MR-111 gear

Greetings all,

I’m in the process of getting my No. 4 up and running, and have a question about the gears on the form roller assembly. My understanding is that the MR-111 gears are not supposed to rotate when at the feedboard, but the back one on my press does (and the one on the front roller does not). The form roller assembly was taken apart, cleaned, and put back together again; I believe it was done correctly, and everything else seems to function as it should. Can anyone tell me what the problem is? If my explanation is not clear, here is a link to a short video:

Many thanks for any insights …


8 thoughts on “No. 4 MR-111 gear

  1. Deborah Johnson - September 23, 2013

    Thanks for the information and guidance, Paul!
    I will work on the things you suggest . . .


  2. Paul Moxon, Moderator - September 21, 2013

    The square bar is the the last piece in the gripper opener linkage. When you step on the pedal the bar protects contacting the cam and pushing back the gripper trip lever assembly (see manual, sheet 106).

    The broken bolt and missing nut can be found at a hardware store. The spec is 5/16- 18 x 1″. I’ve broken one before.

    Do not tamper with the “skew adjustment” at this point. You’re better off getting a machine shop to straighten or turn new rods. Also, if needed, you could take this opprtunity to have new bushings installed in the ends of the steel riders (M-123, Manual sheet 102A). Is there lots of play or do the rider turn snuggly on the tie rods? NA Graphics has the bushings (F-761).

    Form roller Rack: there does appear to be some wear and together with the bent tie rod this could be enough to be the source of your problem, but neither appear to be extremely damaged to allow that much clearance. Images only tell us so so much.

  3. Deborah Johnson - September 21, 2013

    Thanks for the diagram and the explanation about the auto grippers. I didn’t see another latch (though there is a mysterious square bar that comes out from the side of the press just under the MS-129 cam), and there was no nut under the bolt in the slide hole. I pushed back the MS-127 bracket and tried tightening the bolt, but alas, the bolt broke in half! Not a good day in the basement shop.

    Tie Rod: I tried pushing down on the suspect rear tie rod with a screwdriver, and again, this lowered the rear roller gear onto the rack. I think this does indicate that it is slightly bent? How does one go about straightening this, or is there some other workaround? (I just read something in an archived post about a “skew adjustment” – is this just for the rider rollers?

    Roller Rack: Pointed teeth in the picture … these are OK then?

    Thanks so much for the assistance!

  4. Paul Moxon, Moderator - September 20, 2013

    You did say that you lifted the rack.

    The teeth at the gears are not worn. They’re are pointed to allow more tolerance between gear and rack as the carriage begins its travel.

    Auto Grippers: I noticed the sound in video 1. Push the L-shaped bracket (MS-127) back. There may be another latch that swings out and to hold the short end. If not then push back and tighten the nut under the bolt that passes vertically through the slide hole.

  5. Deborah Johnson - September 19, 2013

    In the second video, the gear spins intermittently because I am lifting up a little on the operator side handle of the roller assembly, which drops the back gear enough to engage the form roller rack teeth. Sorry I didn’t make that clearer.

    I think the tie rod end(s) on the bottom frame are probably a little bent. I noticed, when going back to check on the things you suggested, that lifting up on the handle on the non-operator side of the assembly did not have the same effect … the back gear did not drop down as it did when lifting the operator side handle.

    The roller diameter is just shy of 2.5 inches, and the roller height seems right as well.

    Also, the teeth of the rack where the gear should mesh are quite worn down. Would it be helpful to shim that end of the rack up a little bit?

    I had noticed that there were shims under the rear cylinder rack, but didn’t yet make the connection as to why … thanks for the explanation.
    I know we went over this in the class, but could you or someone else explain to me again how to disengage the automatic gripper opening on this press?


  6. Paul Moxon, Moderator - September 19, 2013

    As is often the case, your problem is probably due to more one than one factor. In the second video, the rear form gear spins intermittently suggesting that the gear is sitting too high in relation to the form roller rack. This could mean that either one or more tie rod ends on the bottom frame that holds the form rollers are bent or that the roller height is set too high. Less unlikely, is that the roller diameter is too large. It should be 2.5″.

    The rear cylinder rack is designed to be raised, by shims, because the cylinder is automatically in trip mode until it clears (passes)the ink reservoir drum, otherwise the drawsheet would catch ink. (This is true for all Vandercooks that have inking assemblies prior to the SP series, which is the opposite.)

  7. Deborah Johnson - September 19, 2013

    Thanks for your reply, Paul.
    Yes, the rack is present – as I look at the assembly with your explanation in mind, I see that the back part of the assembly raises slightly as it goes back to the feed board:

    I tried raising the front part of the roller assembly a little bit with the handle, and doing that drops the back gear enough to mesh with the rack:

    Perhaps adding something under the front roller core where it sits in the carriage to raise it a bit might fix the problem, but with the top assembly in place the oscillator/rider roller stop turning when the roller assembly handle is lifted enough to bring the back gear to the rack:
    After taking this video I tried raising the top assembly a little bit as well, and that started everything turning again – so maybe something to raise both a little bit in the front?

    Suggestions? Or is something else amiss?


  8. Paul Moxon, Moderator - September 19, 2013

    The gear should be prevented from turning because its teeth are meshed with the form roller rack. This is the reason for the whole clutch assembly. A photo of this area of the rack, with the carriage rolled forward could tell us the reason. Could it be that the rack on your press isn’t present under the rear gear?

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