Comments on: Form roller clutch on a No. 4

By: Barbara Hauser

Barbara Hauser — Sat, 08 Sep 2007 03:24:16 +0000

Thanks so much Eric, Paul, and Fritz. I feel honored to be advised by such seasoned experts. I shimmed the cam-wedge with some of those peel-and-stick lead strips that golfers use to increase the swing weight of their clubs. It’s only about .090 thick, but that’s all it took to increase the tolerance to the range Fritz mentioned.

To follow through on Fritz’s comment that the roller pins should be round, I am submitting another post so I can include a photo.

Paul, thanks for promoting me from newbie status. I’ve been blessed with good teachers (including you three). I’ll feel less like a newbie as soon as I have actually printed something on this press.

Thanks again,
Your humble apprentice,
Barbara

By: Fritz Klinke

Fritz Klinke — Fri, 07 Sep 2007 02:34:32 +0000

Nice pictures. The blueprints indicate a clearance of .010 to .020 between the “clutch throwout lever” (the naval bronze casting)when the pins in the roller ends are not being pushed in by the throwout lever. The clutch pins are cyanide hardened steel, but they do wear over time. We have new clutch pins, but no new bronze castings. The pins should be round on the end, and if that is not the case, then maybe they should be replaced as well as Eric’s recommendation for repairing the throw out lever.

By: Paul Moxon, Moderator

Paul Moxon, Moderator — Fri, 07 Sep 2007 00:36:18 +0000

Once again I’ve been beaten to the punch by Mr. Holub. Bravo Sir!

Barbara: your mechanical acumen and ambition means you are no longer a newbie. You have accurately diagnosed the problem with your press. You already know the answer: clearance is sufficient when the form roller gear and the clutch block no longer makes contact when the carriage is at the feed board and you no longer hear the clacking sound.

By: Eric Holub

Eric Holub — Thu, 06 Sep 2007 23:44:19 +0000

That is considerable wear on the flipper (which is bronze). Have a welder braze or solder new material into the holes and level them off. There might also be a lot of wear on the pins too, but replacing them wouldn’t necessarily make enough difference.
A temporary fix is to find the cam-wedge that pushes the flipper, and shim it out enough to get sufficient clearance; might just take a brass or a two-point lead. (There should also be a spring that pushes the flipper away from the pins except when the cam is in contact, which would reduce wear.) But the wear will continue and at a certain point in over-shimming, you’ll see wear from the end of the gear as well as the pin.
This is one of the many reasons to pay attention to the label on the press:
“Always lift inking rollers when press is not in operation. If rollers are left turning on ink drum, the ink will dry faster and the rollers will be subject to needless wear.”