Ink Drum, oscillator and rider rollers

Hello everyone. Could someone please tell me what could be causing this uneven spread of ink on the ink drum? Could it be the press leveling? I’m not sure it is 100% level.

I’m also attaching some photos of my refinished oscillator and rider rollers. I think they definitely improved the inking, I didn’t refinish the ink drum because it is a pain in the back to remove it again and I had already removed rust with evaporust. So what do you think?

IMG_9969 IMG_9942

IMG_9966

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John Henry
Editor
10 years ago

Eric mentioned the squareness of the frame which holds the rollers. It could be that the rollers are hitting at one end, but not the other not due to height of the rollers, but lateral position. You might be able to check the distance from the roller shaft to some fixed point at each end and see if that might be an issue. If the frame or the roller carriage has been slightly twisted or racked, that could easily push one end of the roller
away from contact.

If the above is out of position, you still could level the rollers when away from the drum, but their contact with it would be effected.

Just one more thing to check to get you back to printing.

Jonathan Jarvis
10 years ago

ta 4 photos, yes mine is the same except the bearings are made out of hardened brass or similar(seems to be a better idea), what is important is the two parts male and female sit snugly together, no wobble(if it wobbles it could one is worn more likely the rosewood),no flats on the male cone(which I doubt as the wood would wear first): if the bearings have worn into the rosewood by being loose, the cone could have really made the far inside of the female part much bigger……..I would replace the rosewood, cos you have only just about”finished’ restoration, better now than 20 years down the line, you’ll feel happier about it, even though this might not be the problem. good luck.

Jonathan Jarvis
10 years ago

hi Enrique-on my Western 4(licensed Vandercook copy) the drum has a metal face each side with an inset hollow cone, and these locate into coned bearings located and locked in from each side of the press, don’t overtighten or it is too much friction. Because of lack of oiling /grease ( I use car cv joint grease, nice and light but sticky)on my machine before arriving, there was a flat on one cone so the drum was not level and moved side to side scoring the side of the press, so I filed of the point of this cone slightly, which meant it could more fully insert into the female counterpart in the side of the drum so the cone sat inside ensuring the drum was fully supported….yes, I echo don’ overtighten the chain too. These presses would benefit from a grease point/oil point being fitted when manufactured……..

Eric Holub
Editor
10 years ago

An ordinary spirit level won’t measure level of drum relative to bed with enough precision. I use a machinist’s surface gauge, usually with a dial indicator attached. More low-tech, one could also use a straight edge placed against a solid plate on the plate base. Shimming under the base would allow the straightedge to touch the drum precisely at a tangent. I repeat, the drum should be higher than type height to get sufficient contact between drum and rear form roller to drive the inking system.
Every 4 I ever washed up has had some lateral motion to the drum.
The mechanism of the 4 drum uses a bronze shaft held between screws in the frame, and wooden bearings. There is no adjustment possible. Some wear is to be expected. Where I have examined this, it is always on the drive side, which I see as a warning not to over-tighten the chain.

Jonathan Jarvis
10 years ago

if there is any movement sideways to the ink drum, this would indicate the drum bearings were not reset to make the drum level and or bearings are worn(if there is for example scoring to the inside of the press chassis from the rotating drum this indicates previous wear to the drum bearings/not being set properly, did the drum move side to side when you bought it before restoration?);if press is set level in x and y dimensions then it is much easier to check level of ink drum and all subsequent rollers etc with spirit level to get near enough to make final adjustments.

Eric Holub
Editor
10 years ago

There are two basic ways of examining roller contact, the stripe test and the pull test.
Stripe, or jerk-stripe, is done when rollers are fully inked, then let to come to a complete stop. Depending on press design, you might quickly disengage the rollers, or jerk them forward (by flywheel or by inching the motor) so that the residual stripe of roller contact is brought into view. How thick the stripe should be depends on roller diameters, but in all cases the stripe should be of consistant width across its length. On the Vandercook this is a critical test of drum-to-form contact.
The pull test is done with strips of paper or film placed in the roller nip toward the ends of the rollers. here it is done one roller pair at a time. Pull the test strips out and feel for an even tension. There were even test devices that used steel leaves and a spring gauge showing relative tension. On offset dampeners sometimes a sandwich of three layers was used.
The stripe method is a common test on any inking system, letterrpess or offset. The pull method was also applied to offset dampening systems where no jerk stripe could be seen, but contact as still a critical factor. On both inking and dampening systems the final test was the drop stripe onto the plate, and this can be done on a full solid letterpress plate. Ink up, lift form rollers, bring carriage over form, drop rollers in place then lift. Examine stripe on solid form. Again, it should be an even stripe.

Eric Holub
Editor
10 years ago

Bed and drum should have parallel surfaces. Rollers must be set to form surface for correct inking, and drum should be slightly higher and level for drive and distribution. If form and drum have skewed planes, trouble. If bed plate is off, trouble.
Gerald Lange has stressed levelling of press, but has also recounted un-measurable improvements just from moving press within shop. There is voodoo at work among other factors.

Eric Holub
Editor
10 years ago

You can’t level the ink drum on a No. 4 as can be done with a 2190s. Shaft and/or drum bearings could be worn on the low side. But in any case the drum should not be blamed unless you know for certain it is not parallel with the bed (and relaitve to the bed it should also be slightly above type-height). The light ink on the far end of the drum might just be from bad contact between it and the form rollers or between the form rollers and the distributors, all of which have their own adjustments. The forms rollers can move up and down and the distributor carriage can be adjusted for skew through sliding blocks on the inner side of the carriage. Contact can also be hindered by damage to the support rods of the distributor carriage, if for example they have been dropped.
I’ve seen 4s that despite new rollers, and careful setting of them, will still squeegee the ink over to one side. Don’t have any answer for that.

Ray Nichols
10 years ago

The leveling issue doesn’t seem like the solution as it is not inking at both ends of the ink drum.

It seems like the main problem lies with the ink drum.

Possibly in cleaning the rust off of the ink drum with the Evaporust you’ve crossed some tipping point by removing too much of the surface and that you may need to have the ink drum milled down.

If this was your first time inking the press it isn’t unreasonable that the problem was the fault of the previous owner.

It seems like you could put a good straight edge against the ink drum and you could see the problem if I’m correct. Put a straight edge on it (has to be a good one) and shine a flashlight behind it and see if there is any light leak.

Good luck.

Widmark
10 years ago

I had a similar problem with my 219os. I don’t know if the solution is applicable to other models, but on mine, you have the ability to level the ink drum, separate from leveling of the press. When I first got mine, it was not leveled and I saw results just like yours, which eventually lead to so much more contact on one side of the roller that it damaged the roller.

I think a slightly unleveled press can cause ink migration (and eventual rail wear from uneven pressure) but more extreme issues that are that noticeable might be something else. An uneven ink drum, drastically uneven rollers, or transfer or roller wash or the vaseline onto the drum.

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