Inconsistent inking on Windmill
Hey all, I am hoping somebody can give me some insight on an inking issue with my 10x15 Windmill.
I recently picked up a 50’s era windmill in seemingly good shape. Registers great, feeds great, everything is pretty solid.
When i began my first couple of press runs, I noticed that about every 5th print would be suddenly light, and then the following print is too dark, and then 3 prints in a row that look good, then repeat (light, dark, fine, fine fine, etc.)
I have several years of Windmill experience and, fiddled with the roller height settings a bunch, and made sure the tracks were clean (no slurring), and even rotated the form rollers out with the back rollers, etc., but each time i do a run, i have the same result.
I ordered 4 new trucks, but the problem persists, and my rollers appear to be very clean (the forms were virgin rollers, still wrapped, but were more that 10 years old, just never used).
The pattern of every 5 prints, led me to closely watch the rotation pattern of the rollers, which i found to repeat at about 5 cycles. So it must be something in there, right?
The only other variable i can guess would be the bearings?
I am starting to feel stumped, but am prepared to order new bearings and all new rollers, just to eliminate the possibilities.
Any insights would be great, before i drop a bunch of money on new parts.
Thanks!
old rollers might be your problem, if they are rubber i would try deglazing them before buying new ones, i don’t think it would be your bearings. when you adjust your roller height you should have all 4 adjustments set the same. good luck Dick G.
thanks for the input.
The rollers are glaze free, in fact they are as velvety and clean as any i have seen. They were in the original paper, and had not seen the light of day (or ink) ever. I just don’t know for certain how they were stored for the last 10+ years, so i can’t say they did not sag or warp, if that is even something that would happen to the rubber over time.
My only thought about the bearings would be that the 4 bearings i have seem old and mis-matched, albeit intact, and also don’t seem to be consistently snug on the cores (some of my rollers fit the bearings very tightly, and others seem almost too loose) , but i can’t seem to deduce why this would be causing the pattern i see.
Just hoping that someone else had seen the same pattern of every 5 prints and had a clear solution that i may have not considered.
Thanks for the thoughts so far.
Maybe just out of round. Try testing by rolling over a very flat surface like glass. It just sounds so much like the rollers despite their newness. the stocks or the rollers may not be right, but appear so
.
also if you are in a cold climate and don’t have heat where your press is it could cause problems. ink and rollers don’t like to be cold. i don’t think because the bearings don’t fit tight that its a problem, some of my rollers i have to press the bearings on and others they fall right on. Before buying new rollers you might try changing your ink, maybe the ink is bad, although almost any ink will run on a letterpress.
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Check your impression collar (shear collar ) we find that whilst kiss cutting on self adhesive stock with such fine tolerances that the slightest damage to the collar will produce a regular pattern ie two sheets cut proper then one does not two sheets good one not , never had your problem but then i have only ever blown the collar die cutting ,and one thirty years ago when i picked up 6 sheets whilst printing on board ! Checking will cost you nothing at all and you will need a very high magnification glass to look for the cracks ,a printers linen prover at the least !
Another thought ,
check the pawl and gear on your ink duct roller is not forwarding the roller a few turns then jumping the ratchet ,this can produce a consistant pattern of light and dark images , i just spoke to my partner and he is as stumped as you are , amazing really he has been doing this for years (1950 on ) Me ,im a baby only got 31 years in so far .
You could watch the oscillation orf the rollers on the topdeck (ink train) make sure the inkers all stay parralel at all times and that no inker is jumping at the end of its travel check that they are all set in even contact and according to the age of the machine check that the rollers are travelling cleanly across the machine and at no point binding against the side frames for any reason at the end of the travel of the oscillators even the rider rubbers can jump sometimes so watch for movement up there ,you dont have to be in impression or feeding so ink up and watch the top deck for bumping and jumping .
Oh yes pull you ink form rollers in and out make sure the inner arms are free and easy to pull in and out Albeit that there are the springs to overcome but you will see if the arms are sticking at all
Make sure trucks and rollers are the same diameter.
I was dealing with some inking issues a few months ago, involving an unsolvable ghost. Finally I checked the diameter of the trucks, and one of them was smaller by 1/32”. I replaced it with a spare and the problem was immediately improved.
Thanks for all the input so far, it will give me something to think about going forward.
As for cold, yes it is less than warm in my studio at the moment, and it has been kind of a hassle, however, the ink looks like it all lays smooth once warmed up. Also, my vandercook runs like a champ in the same conditions.
I will check the new trucks again. I did notice that they were slightly larger in diameter than the old trucks (which were all pretty thrashed at this point) , and i had to lower all the form rollers to meet the form properly, but i did get all 4 new trucks from the same place, in order to ensure they would be consistent. But i will double check anyhow.
I will watch the upper deck more to see if anything looks odd. Generally the Ink all looks great up there, and since the every 5th issue correlates to the form roller rotation, i figured it improbable that some small ink pattern in the upper deck would, also match and carry through to the form roller rotation pattern, but who knows.
In the past, i have run 5 other windmills, all with their own little quirks, but havent had this specific issue, and have run some pretty random combinations of trucks and bearings and rollers in questionable condition.
Usually my inking issues have been very random with intermitent issues, but never a specific pattern, so i am keeping my focus there in hopes it will be clear at some point.
Perhaps the suggestion to borrow a set of rollers and whatnot for a day could tell me what direction to go in.
Thanks again, and i am still listening if there are any epiphanies out there.
:)
If your ink ers to the forme are not round and paralell you will see them flashing when they are picking up ink from the main distributor , when the rollers contact each other properly they appear to look matt finished when inked , if they were not always in contact they start to look like they are flashing because undisturbed ink on a roller will look shiny and as the ink is worked it appears to be matt in appearance.