No. 4 grinding chatter

We have a No. 4 who is the work-horse of our print shop (at MCBA). In recent weeks, it has started an awful chattering noise, that continues to get worse. At first I thought it was the gear and the clutch on the form rollers that were rubbing together. But on closer inspection the gear appears to be dragging over the rails, making a loud and unpleasant sound. Almost as if the roller is too low, and dragging some how.

Here is a list of the things I have already done in an attempt to repair this problem:

  • replaced with new MR-112 collar. The end of the roller core where the indents for the set screws to the collar fits is quite junky and marred.
  • replaced with new MR-110 pin
  • replaced with new MR-111 gear.
  • checked and shimmed the plate on the outside of the rail where the clutch plate connects
  • resurfaced the brass clutch plate itself.

Because people need to continue using this press, I have devised a work around. Each time the carriage returns to the top of the bed, the operator must raise the rollers and “gently” set the rollers down again. It’s a pain, but it works.

Looking for a more permanent and concrete solution I looked to the vanderblog. Reading through this post https://vandercookpress.info/vanderblog/2010/08/new-rollers-slightly-different-diameters/ I read tell of raising the top distributor rollers slightly. A fellow named Eric described it in 2010. For the life of me, I cannot figure out what he is talking about. I have also measured the diameter of our rollers, and they seem smallish to me. The rubber was replaced in Jan 2010. Shouldn’t rubber rollers last longer than 5 years? Is it time to replace them?

Any advice is helpful. I am not afraid to get in there and do the work, I have just run out of ideas on this one.

Subscribe
Notify of
5 Comments
Newest
Oldest Most Voted
Inline Feedbacks
View all comments
Eric Holub
Editor
9 years ago

One thing I notice from this photo: the sheet supports are positioned right over the grippers. If the specific form needs it, fine, but as a regular position it leads to excess wear of spring and gripper head. You can see the scarring of the grippers.
You wouldn’t want them over the sheet guides either but rather in the open spots of the gripper bar.

Paul Moxon, Moderator
Admin
9 years ago

I apologize for the previous graphic it was extracted from a manual from an oldstyle No. 4 as a side view drawing does not exist for the manual for the later No. 4. I will attribute my error to travel fatigue, which continues through Sunday. Below is a photo showing the slotted horizontal bracket on a No. 4.

Vandercooks roller specs are proprietary information&mdashparticularly face length and position on the core—owned by NA Graphics sand used to order cores they sell. However diameter (2.5″ for the No. 4) and durometer are and were specifications listed in the equipment catalogs. The page you reference is for my private research use and should not appear in the menu. Of course, face length and position can be determined by measuring your existing rollers.

Paul Moxon, Moderator
Admin
9 years ago

The adjustment Eric suggested refers to the slide plates shown in color in the image below.
He said:

To shift the position of the upper frame, there are blocks on either side of the carriage, that bear against the ends of the cross-rods of the upper frame. Loosen the screws, shift the blocks, re-tighten the screws, and the rest position of the upper frame can be moved (or skewed) as needed.”

Five years can be a long time for synthetic rubber rollers that see constant use. The the kind of solvent and exposure to florescent light are factors.

Copyright © 2024 vandercookpress.infoTheme by SiteOrigin
Scroll to top
5
0
Would love your thoughts, please comment.x
()
x