No. 4 rear roller will not rotate

After much successful use, I had to move my Vandercook 4 proof press. In putting everything back where it is supposed to be, I have encountered a problem (actually several problems, but I fixed the sheared drift pin on the gripper foot lever as well as the sticking and bent grippers). After much scouring, I didn’t see a reference to the newest problem. The form roller that makes contact with the ink drum will not move. When the ink drum is rotating, the roller makes contact, but stays stationary. Thus, no ink can be distributed. I am not sure if this is a consequence of my having removed the cylinder to make the press lighter for moving. Is it possible that I did not index the cylinder properly, so that he gear teeth are misaligned? In general, the press does not look out of alignment, but I could be one or even two teeth off without knowing it. The other possible culprit seems to be the clutch assembly. I had problems inserting the bottom frame form rollers, they did not want to seat properly. The roller clutch trip was engaged, and in the way. I cranked the press a bit, the clutch disengaged and the frame dropped into place, but still no movement as it contacted the ink drum.

Any suggestions would be gratefully accepted, I want to get printing again soon.

5 thoughts on “No. 4 rear roller will not rotate

  1. Patti Montgomery - May 29, 2009

    Press Update:
    Although the clutch pins do look worn, my issue related to all the old oil and grease that surrounded the entire roller gear and clutch assembly. After a thorough cleaning, and re installation, the clutch assembly functions smoothly and the rollers turn correctly when in contact with the ink drum.

    Not only were the clutch pins stuck, the nyliners were gunked up and the gear collar had slipped on one of the rollers.

    Tomorrow I will try inking and find out if the rollers are the correct dimension for printing.

    Thank you all for your comments and for the very useful articles posted on this site. They helped immensely as I was trouble shooting this problem.

  2. Paul Moxon, Moderator - May 28, 2009

    When the gear and clutch block wont separate it is likely the the clutch pins (MR-110) are worn flat and need to be replaced. The pins may also have dimpled the clutch plate.

  3. Patti Montgomery - May 28, 2009

    Thank you Paul and Eric. I took apart the form roller bearings and cleaned everything a bit. My press is quite dirty and there was a lot of thick residue between the two halves of the form. I then reinserted it into the press. When the frame is in the up position, both rollers, front and back, spin freely. In the down position, with the back roller making contact with the inking drum–tested it with a piece of paper, the back roller will not turn. I believe the problem is with the rear clutch assembly. The clutch block is not completely separated on the back roller. I looked at a friend’s much cleaner press and saw less spring and more clutch separation. Maybe like the bent and sticking clutch pins, I have a problem with built up oil, grease and debris. I have not ruled out that the rollers are too high or low, or that they are the wrong dimension, I plan to test them with my roller gauge, but this press functioned perfectly at one point, and the rollers were carefully stored indoors. My plan is to disassemble the clutch block and gear and clean everything up. With this course of action, are there any tricky pitfalls that I may come across? By the way, I did find nyliners on the operator side of the assembly, but didn’t take apart the opposite side yet. Any other thoughts?

  4. Eric Holub - May 28, 2009

    When inserting the lower roller frame at the feedboard, you have to dip the right-hand side and come in at an angle so that the clutch pins don’t sit on top of the clutch plate. The lower frame must be seated correctly.
    If both of the clutch blocks are completely separated, and the rear roller is actually in contact with the drum, then the rollers should turn. Take off the upper roller frame and see if anything changes (if the rear roller starts to turn then, a stuck front roller may be retarding motion). Lift the form rollers with the handle and make sure thay are completely free-spinning. Test with paper feelers that you actually have contact with the drum. If you need Nyliners and don’t have them, that could also affect roller contact.

  5. Paul Moxon, Moderator - May 28, 2009

    The index of the impression cylinder in the carriage is unlikely to affect the contact between the form roller and the ink drum. More likely, the rollers need minute adjustment. They may also be undersized, the diameter should be 2.5″.

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