I undertook the arduous task of adjusting the 6 cylinder carriage bearings on my SP15, after still experiencing uneven inking and impression with newly recovered rollers.
Thanks especially to Gerald’s comprehensive “Adjusting Cylinder Carriage Bearings” article, without which I never would have undertaken the ordeal:
And with Fritz’s recently found comments within Paul’s “Common Operator Errors” article, I may get even closer to nearly perfect impression adjustments:
– – –
My problem is I find the upper/front/non-operator side bearing (X-12232) no longer spins freely after re-tightening the bolt head after adjustments, whereas it does by just hand tightening it.
All other 5 bearings spin easily after my adjustments are done and the bolts are torqued down. Could it be that the shaft/pin holding this bearing into the carriage wall may be warped and ends up squeezing the bearing to the rail at the final tightening? I don’t own a torque measuring wrench but I know I’m not tightening this offending bearing any more than the others.
Any insight appreciated.
. . .
SEPARATELY and to clear further confusion:
After reading all articles and then adt’l comments in Ron’s May 21, 2011 “Cylinder Carriage Bearings Questions” article, I’m still unclear with the terminology. Each time “TRIP” or “IMPRESSION” is used in reference to the bearings, it is never clarified if we’re dealing with bearings ABOVE or BELOW the rail.
Please correct the following if I’m wrong:
– I’m left with the understanding that the IMPRESSION bearings are situated UNDER the rail, they control the amount of impression by squeezing the carriage tighter/looser to the rails while printing and get adjusted in PRINT MODE
– whereas the TRIP bearings are situated ABOVE the rail, they control carriage and roller assembly height, and they get adjusted in TRIP MODE.
I think I and many other owners would greatly benefit from clearing up this confusion. Thanks for all your help and comments, past and future.
Yup Gerald, I believe I now have the old 6-bearing adjust procedure down to a T! Took your article to give me enough faith to undertake it. I can now lay down a kiss impression on .001″ tissue paper with consistent side to side impression, as well as down the length of the entire bed, I almost impressed myself with the results! That one was worth a cigar :)
Thanks again, Yvon
Good to hear you have gotten clarity on this. It still scares the crap out of me. An acquaintance recently had a bearing explode on her and I had to tell her replacement, which is dirt cheap enough from industrial suppliers, also entailed adjustment!
Thanks very much for clarifying the ambiguous terminology for me Paul.
Yes, I managed to tweak/equalize impression quite nicely with the 4 impression bearings (that roll on the underside of the one and only set of rails on my SP15).
And just to keep things slightly mysterious, upon going back to the press the following day, I found my offending non-operator side trip bearing rolling freely with the bolt head torqued right down. Go figure…
Well, at least now I am fully clear on what bearing does what and how to adjust them.
It amazes me that you keep all these presses straight as well as you do!
I could certainly be incorrect, but I believe on the UNI III the bearings that ride on the top of the bottom rail (lowest on the press) are the trip bearings and the bearings that ride underneath the top rail are the impression bearings. What I cannot do is correlate this to a numbering schema as I am not sure where this is derived from.
My assumption is based on the trip bearings as previously described moving freely back and forth while on print (i.e. – not tight against the bottom rail) and the impression bearings moving freely when the press is in trip mode.
Eric seems to agree with this based on his post in Itsfancy’s thread regarding the work he is doing on his UNI III.
Arg, writing from my faulty memory. Working too little sleep here at Penland. I will see another in a day or two. Meanwhile, can someone with a Uni III confirm.
I am confused now. In your reply post related to my post:
You state that bearing 2 and 4 are the trip bearings for the Universals.
You may be right that your troublesome bearing is warped. This is less critical that the impression bearings. Is impression even across the bed?
And yes, impression bearings roll on the under rail and for SP series presses the trip bearings roll on on the bed bearers. On Universals there are four bearings on each side of the press: 1 and 3 are trip bearings that roll on the upper under rail and 2 and 4 are impression bearing that roll on the bottom rail.