Adjusting Ink Roller Height [15-21]

As the process of getting to know the press continues to unfold, I’ve been putting together some notes on various discoveries & lessons learned. This post is concerned with adjusting the height of ink rollers.

While these notes may appear overkill for a relatively simple process, some may be as ignorant as I was about what this adjustment entails, so I’ve put the notes, along with a few diagrams, together as a web page. I hope it might prove to be of use.

Please let me know if you notice anything incorrect about the notes and I’ll update the web page accordingly.

http://www.greenboathouse.com/15-21/adj-ink-roller-height/

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Eric Holub
Editor
17 years ago

OK, Jason, if the screw-heads lift again, press on them with your fingertip. If you feel rubbery resistance, that would suggest something pushing on the roller covering. If smooth movement, keep pressing up and down until you can see exactly where the play or upward force is (for example, from warpage). Or is there a metallic resistance like, say, the screws themselves binding up somewhere?
Is “thread lock” a reference to Locktite? Vandercook used that fluid on screws to keep them from shifting. Some people have been driven to frustration by it. I haven’t experienced it myself but was told heat is the way to free up a Locktited fastener.

Eric Holub
Editor
17 years ago

Jason, I do have sympathy for the situation you are in, no discouragement intended. When the screws were lifting out of their countersinks, where were the rollers? Were they sitting on a form or over empty bed? Were all four screws lifting?
Under normal conditions the rollers will drop from their own weight, and the setscrew keeps them from lifting (as well as holding adjustment). A loose set screw could allow a high form to raise the rollers. Or a warped frame might not let all four screws seat properly–check it aginst a flat surface. But it is hard for me to imagine a situation where the adjusting screws wouldn’t seat unless there were an upward force acting on the rollers or blocks. Maybe it’s printergeists.
Have you confirmed with Fritz that your form rollers are the correct diameter? I’ve seen undersize rollers that wouldn’t contact the distributors or form properly. But oversize rollers might present some strange conditions too.

Eric Holub
Editor
17 years ago

Jason, set-screws are a very common thing and are used to hold a position where it may shift due to vibration or motion. It has nothing to do with “thread integrity” because perfect threads are subject to the same forces. Overthinking and premature conclusions are leading you down false paths, and others with you.
I repeat, one or two more complete (and accurate) diagrams would be worth far more than so many “simplified” diagrams with so many words of explanation. The adjusting screw threads only engage the upper half of the bearing blocks; the lower part and the carriage section have plain holes. And the countersunk head of the adjusting screw rests in its countersunk hole–it should never lift out as shown in the diagrams. It is important to get these things correct if you want to understand it yourself and explain it to others.

Having looked at this style of ink carriage many times, I know that many people have been confused by it. Incorrect assmbly of the parts is very common. For example, it looks like yours does not have its oil-holes to the outside where oiling is possible, and is missing the retainers to keep the nyliners from falling out (those are simple sheet-metal “U”s, only on the non-gear side, that are held in place by the bolts that hold the blocks together). They are just long enough to cover the flange of the Nyliner, and keep the outer Nyliner from falling out, which is common. (Retainers are easily fabricated out of metal backing from a photopolymer plate.)

Paul Moxon, Moderator
17 years ago

The 15-21 is the last model to have this type of form roller adjustment: a removable top frame oscillating roller with two riders and a bottom frame for the form rollers.

The Universal series introduced the carriage-mounted oscillating roller with a single rider and the “quick change” form rollers with a bearing assembly and adjustment screw mounted on the core ends, which fit into brackets on the carriage.

The Arm
17 years ago

Jason,
Thanks for the explanation and diagrams. My 320Gs have an similar setup for inking roller adjustment.

Paul Moxon, Moderator
17 years ago

Hi Jason, welcome aboard. Your efforts are welcomed. It’s all about expanding the collective knowledge and extending the useful lives of these presses.

As to the nomenclature in your notes: in most Vandercook manuals the “setting screw” is called the “lock screw” (though some do call it a set screw), “axels” are called “roller cores”, and “blocks” are called bearing blocks (each set is a machined, matched pair with numbers stamped into one end).

It’s also worth noting that brass bearing blocks (an orginal engineering spec) were bored to fit the roller cores. Steel bearing blocks (an engineering improvement) are bored to a larger diameter to accommodate nyliners (nylon bushings) fit onto the roller cores.

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