Uneven rollers/ tapping the rail options?
I’m having issues with my rollers and I want another opinion before I replace them. When the rollers are inked and sitting on the rail 1/3 down and I use the roller gauge to check the roller height I get different readings all the way across, when the rollers are stationary. I get about an 1/8 inch on the sides and almost nothing in the middle. I’m using a 12x18 new style c&p. I have a video but it wouldn’t post on this site :(.
I also would like to know how you tape your rails, I have quite a bit of strapping tape on mine and I’ve read that’s not a good option.
I’m in Austin, TX area so if there’s anyone near by me that might be able to help me troubleshoot, I’d like to connect.
Thanks for any help in advance :) hopefully I explained it ok.
Assuming your trucks are the correct size and not too worn, remove all of the strapping tape and lay a straightedge on the rail - if it’s not flat, you have a problem. Repetitive wear over the years from steel trucks can cause irregularities which are difficult to resolve. If the rails are relatively flat, tape them with silver tape, which will lay more flat than the strapping tape. Usually a layer or two is all it takes.
Getting a reading of 1/8” ink stripe on the outer edges of the rollers and no stripe in the middle?
Adding tape to the rails isn’t going to help that problem..
Seems like you have issues with your rollers.
Michael
As just another confirming test, I would put a straight edge across the rollers in the press and see if you can see the same situation: that the straight edge is not contacting the rollers in the middle. Although I don’t think this is happening, there is a very faint possibility that the roller hooks are pulling so hard on the cores (shafts) that they are bowing the rollers.
On another subject, rollers occasionally have been known to swell on the sides because, unlike in the middle, the ink and solvents have one more surface to be absorbed into the roller material, and that is through the ends. For this reason, it is important to clean and dry the roller ends after each use.
Yet another test is to roll a lightly-inked roller across a sheet of paper or film. That can show any low spots.
A more technical test is to put the roller on a set of machinist’s V-blocks. Sighting and rotating can show irregularities, and they can be measured with a machinist’s surface gauge or indicator.