C&P 8x12 roller recomendation
Hello,
I currently have a set a Ramco rollers that I have been using for about 1 1/2 years on a C&P 8x12. This is my first press so a lot of learning has went into that time. I filed down my rails with a jig until they were flat again with zero deviation on a dial indicator and taped back up to type high. I would still get some uneven inking and would chase it around with tape to get a good print. I measured the trucks and they were a little out of concentricity so I made some aluminum ones with less than .0002 total indicator runout. Things are better but I’m still getting a little uneven inking at times and I can rotate the rollers and it moves the light spot on the print. I suspect that the roller is a bit out of round or not concentric on the shaft. The cores have center drill holes but if they are not dead nuts perfect the outside diameter of the roller will not be concentric with the outside diameter of the core. Enough of the rambling. So who makes an outstanding set of rollers to go on a C&P 8x12 when using photopolymer plates. I will probably keep this set as a backup ad get a whole new set with new cores. So the new ones would need the pinch marks and need to be compatible with keyed trucks.
Seems you’re well equipped for this — why not try sticking the roller between centers on your lathe, and indicate for roundness? If you used a ‘last word’ style indicator and a bit of oil on the roller, I think you’d prevent any chance of the probe digging in and destroying the roller…
Have you contacted Ramco? You may be able to send them back for inspection. That way you will know for sure what is causing the ghosting. If you were my customer I would want to be the first one to know you were having problems.
keelan,
the lathe i was using has a horrible tailstock on it. it cannot be adjusted to where a test bar will run true so sticking it between centers on that thing would be useless. i may try to throw them on a surface plate and see what happens on some v blocks.
jpk2525,
I have not got a hold of Ramco yet. i have to find out where i put my trucks at so i have some good measurements to give them. i also wanted to have some definitive answers on the measurements of the rollers.
Right now the work is busy so i can’t do without a set of rollers. to be honest a 2nd set would not be a bad thing either. So I’m looking for recomendations from everyone on what rollers they love that gives them great results using polymer plates.
machinehead.
Even with a horrible tailstock, you can still indicate for out-of-roundness, but I’m guessing that you’re trying to check for taper… You could do that by not moving the indicator and flipping the roller end for end between centers.
And to answer your original question — NA Graphics came highly recommended to me from both hobbiest and professional printers. I haven’t used my rollers yet, but from what I’ve heard from others, I’m not expecting any problems.
I have had trouble with uneven inking also. It took me a while to find out why. After making sure that the rollers were set at type high and that there were no low spots on the rollers I found out that the rollers were not rolling over the form but sliding. What was happening was when I washed the press I got roller cleaner on the roller trucks and the press bearers and the rollers were sliding instead of rolling. After cleaning the trucks and bearers with typewash to get the oil and such off the problem went away. Any oil or grease free cleaner will do as long as it doesn’t harm the rollers and trucks. If the rollers slide or skid over the form they act like a squeegee and won’t leave a good layer of ink on the form. Rollers have to roll over the form to ink form properly and to get quality printing. I hope this helps. It did for me.