The ink drum on the recent #4 was frozen in place–bound up by years of uncleaned ink, and it was also in contact with the operator side of the recess where it sits. After much penetrating oil and some heavy manual ink removal, I loosened the lock nuts on either end of the drum, and the screws they lock, to center it and free it from the bind. The drum spins freely now, is cleaned of build-up on the ends and around the chain, and doesn’t strain the motor; however, after centering the drum, it consistently migrates back to the operator side of the press when the motor is on. I can push it back to center with a screw driver while the motor is running, but it then migrates back to the operator side of the press.
I don’t want to strip or round off the lock nuts on the drum; is the solution simply more torque? Otherwise all seems to be good. Will look forward to reading thoughts and ideas, and thanks.
Jonathan, Paul, thanks. After another session with the press, it appears more (gentle) torque was the answer. The lock nut and screw on the non-operator side were quite firmly tightened, but those on the operator side were somewhat looser. I backed the nut all the way out (without removing), then positioned the drum where it should be, and then tightened the screw as much as I could with the widest flat-head screwdriver I could find. Then I tightened the nut back down. The drum now turns, without lateral play.
Glad it wasn’t (or doesn’t appear to be) the F-760s. I’ll keep an eye on this, though, and if the problem returns I may re-post for some additional advice.
Thanks as always, and Paul, especially, for this forum!
The cones Jonathan mentioned are the wooden bearings (F-760). It could be that they have slid into the drum. A note on the assembly drawing says that the bearings should extend 1/64″ outside the drum.
There is a danger perhaps that oscillation will have worn the cones to an uneven profile, and made worse by lack of lubricant in these bearings, which would only worsen if not checked out.Also may cause inking problems of you are relying on inking rollers putting pressure on the ink drum to keep this “level” , thus increasing wear on everything.