My wife and I recently received replacements rollers for our 12x18 C&P New Series press.
After installing all three rollers, we discovered that the left lower roller arm (as you’re facing the delivery board) is no longer moving in and out smoothly. It slides out to the necessary extension as the rollers move over the press bed,
but will not return to its original position once it moves up over the ink disk. It remains stuck in its upright position and has to be gently tapped down with a rubber mallet.
All of the roller ams were moving smoothly before we put in the new rollers and the shafts are all well oiled.
Any idea what might be causing this and what we can do to fix it?
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Could be that the shaft is slightly bent.
Once, I had a bent shaft due to an accident with a home made gripper that was actually too short. It got caught underneath the bottom roller and bent that left hand shaft.
I had to remove it and beat it with a heavy rubber mallet, with the shaft secured in a vice. Then when I got it almost straight, it was still binding.
I then sanded the shaft down enough so that it was no longer binding. Oiled it up and away we went.
I’m not saying that this is your problem…but it could be.
Don’t remove the shaft unless you have to. They can be difficult to get back together, with the spring and all. (mine was on an 8x12. It took two people mainly because it was awkward).
If it is binding, you may be able to sand it down slightly with it still in the press until it no longer binds.
DO NOT beat on the shaft or roller saddle with it in the roller carrier in an attempt to straighten it. The carrier is cast iron and could (read..will) break.
Again, I’m not saying this is your problem…but it could be.
In my case, it was live and learn…we fix it…we move on.
Thanks David. I thought that I recalled being able to lift the roller arm all the way up prior to putting on the new rollers, but now I’m not so sure. It’s quite possible that it was like that when we bought the press. It only had the two top rollers installed when we picked it up.
I’m assuming that it can run just fine with only two inking rollers. Or am I missing something important by not having three?
Running the top two rollers only is fine unless you’re running a really big form or something that has big solid areas.
i seldom use more than 2 rollers, i print full time, my 12x18 kluge will print a large form (no solids) with only 2 rollers.
If the hook rod slides in and out easily with no roller installed, you could check to be sure that the trucks are the same distance apart on the new rollers as they were on the old ones. Sometimes the trucks being just a bit further apart can cause them to bind against the hooks or saddles, which can cause the rods to not slide smoothly in their bores in the roller arms. Measure carefully between hooks across the press and measure the outside-to-outside of the trucks on the roller — that distance should be slightly less than the former.
Following up on Bob’s point. When I replaced rollers, my trucks would not go inboard (toward the center of the shaft) quite a far as the did on the old ones. This was do to the fact that small nibs on the shaft that the truck slides over were a little larger than the old ones. These nib are there so that the rollers turn as the trucks roll down the bearers.
Filing off a small fraction of the nib can allow the truck to move in slightly further and prevent it from causing the binding described by Bob of AdLibPress.