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Impression on windmill

Hello,

I’m just starting out on a windmill, and in between lessons I’m spending time practicing.

I currently have a problem with impression: The ink isn’t achieving good print impression on the sheet, but at the same time, after a few prints, prints through the sheet and onto the tympan.

Paper is standard 80gsm bond.

The packing behind the tympan is definitely below 3pts, and I definitely have impression turned all the way down. I understand the relationship between the packing + impression settings.

What are some reasons for the ink to print through the sheet, yet not achieve a good impression on the sheet?

The photo attached shows an example of a print, and print through to the packing.

When I turn impression up a little, the print impression does not significantly improve, but the print through the sheet and onto the tympan sheet gets worse.

I’m guessing that the smudged ink on the packing is probably cause by reusing previously printed sheets, by turning the sheet around.

Any pointers are appreciated. Thanks.

image: tt.jpg

tt.jpg

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I cannot explain your uneven impression.
Are you printing from type or a polymer plate?
From your photo you are either using too much ink, or ink which is much too thin.
The dirty mark at the top of the tympan suggests that the tympan is overpacked. Does it fit into the gauge cut into the delivery standard? Or the grippers are set too low.
The fact that you show arcs of smudged ink on certain lines and not others, makes me think you have bent grippers.
The crease near the base of the tympan looks like a soggy packing. It should be perfectly flat and tight.

image: ttA.jpg

ttA.jpg

Ink looks thin. Is the type handset?

Ink on the tympan is the result of a misfeed. Paper didn’t pick up and the form printed on the tympan before disengaging the impression lever.

Is this two sided printing? It appears the arc of ink was made by wet ink on the underside of the sheet. You may not have let the sheet dry long enough so it offset onto the tympan.

Casey
Inky Lips Press

Thanks Bern, Platen Man and Kasey for your pointers…

Firstly answers to your questions:

- I am printing from ludlow that was made up.

- The dirty mark at the top of the tympan I’m 90% sure is not overpacking. The packing is definitely under 3pts, and definitely fits within the guide freely. I think the dirty mark is caused when I’m setting the packing, when I draw the metal rod across the tympan to flatten it. The metal rods I’m using are slightly oily.

- The arc at the top you guys are correct, I was being thrifty and trying to re-use paper by turning it over. But I’ve since stopped this practice.

The original problem I noted still exists, where I cannot achieve an even print on 80gsm bond, without printing onto the tympan behind it.

The photos below document my most recent attempts.
I make at least 7 adjustments, starting with very little packing, and zero impression, and gradually increasing packing and adjusting impression.

Here are descriptions to match photos below:

1
- packing is approx 1.5pts
- print is weak
- yet tympan still gets printed on!
- also included is side view of the tympan

2
- increase packing slightly
- printed impression is still weak
- but tympan print gets worse??? (confused)

3 & 4
- increase packing slightly
- increase impression slightly (still at “0” with 1 fingernail notch)

5
- increase packing slightly - still below 3pt
- impression reduced to zero
- print is better, but very visible on reverse side of sheet
- the tympan is being printed onto significantly

6 & 7
- increased packing slightly - still below 3pt
- impression only ever max at “0” with 1 fingernail notch
- the tympan print is very bad

So in summary, I cannot seem to print onto the 80gsm bond cleanly, without having the tympan printed onto.

I stress that my packing is never over 3pt. The most it ever is in cycle 7, is approx 2.5pt, comprising of 5x semi transparent ~40gsm stock + 5x 80gsm bond behind tympan.

My impression is also ever a maximum of 0 with 1 fingernail notch.

Is the problem my paper stock? allowing too much ink through? Ink? (offset Pantone Red 032C).

Any pointers are appreciated.

Thanks

image: 7 tympan.JPG

7 tympan.JPG

image: 7 print.JPG

7 print.JPG

image: 6 print.JPG

6 print.JPG

image: 5 tympan.JPG

5 tympan.JPG

image: 5 print.JPG

5 print.JPG

image: 4 tympan.JPG

4 tympan.JPG

image: 4 print.JPG

4 print.JPG

image: 3 print.JPG

3 print.JPG

image: 2 tympan.JPG

2 tympan.JPG

image: 2 print.JPG

2 print.JPG

image: 1 tympan 2.JPG

1 tympan 2.JPG

image: 1 tympan 1.JPG

1 tympan 1.JPG

image: 1 print.JPG

1 print.JPG

Sorry, photos have appeared in reverse order

It looks like “Platen Man” is right ink may be too thin (runny)
What type of ink are you using, are you adding anything to it? Try some 24# stock or even a different brand of the 20# if you have some, the 20# you are using might be too porous and ink is flowing through the stock. Are you sure there wasn’t a misfeed and you printed on the top sheet? Eliminate one thing at a time so you know for sure what is causing the problem.

Besides turning the impression lever, are you also pulling the lever out for impression and in for no impression? You shouldn’t be printing on the tympan.

You say you are having lessons,are these of a practical nature, or merely theory?
Why not ask your tutor to solve the problem?
Have you read and understood the instructions in the manual?

To my mind there is something wrong with your method of operation,and the fault does not lie with the machine.

Try turning the forme 90 degrees in the chase and see if you get the same effect.

Ink should not penetrate through a sheet of 80gsm paper, I.ve printed a 4 cokor logo om 13gsm airmail without any sign of ink on the reverse side of the sheet.

From your photos it appears that you are printing directly onto the packing prior to picking up the first sheet; the impression lever must only be moved onto impression after the gripper has hold of the sheet,

From our experience, it looks as if you are printing on the packing. When the machine is feeding paper through, and the impression is on, does it ever miss a sheet? The machine should be set to trip (stop) when the paper feed misses a sheet, but sometimes if it’s not set up correctly it will miss a sheet and print on the packing. Turn the machine down to the slowest setting and watch carefully.

Make sure that whenever the machine misfeeds you turn the impression off (or trip the safety) and you should be fine.

Also, cleaning the underside of the grippers will help you keep the packing clean.

Here is my two cents into what I see. The ink is the wrong ink for metal type. The impress should not push the type through the paper or card stock.
Another thing, you might have oil on the metal metal.
Letterpress work great, but you do have to follow some rules, the type or plate has to be dry, and the rollers have to roll on the type or impage, your roller trucks might not be working correctly and the rollers are not rolling the ink onto the type.

Hi thanks all for the tips - very much appreciated.

Although I may be mistaken, I am extremely carefully with the impression lever, making sure that it is only engaged with stock on its way in - where the gripper has hold of a sheet; and disengaged before the stock feeder switch is pulled out. (I’m sure I misused the semi colon there - but hey I’m trying… :p)

There have been no misfeeds in a long time, especially during the most recent run. Thanks for the tip about cleaning the underside of the grippers hungry.

It could possibly be the ink - which is offset printing based. I will however seek practical advice shortly about my technique. I’ve merely been playing around in the meantime for homework, and to wade through the proverbial and learn through mistakes.

PS hungry did you manage to find another photopolymer platemaker in QLD / Aus? When I was looking a few months ago, I’m pretty sure there was 2 of them in QLD. I know that Louise from Poppy Letterpress has one (but don’t know if she makes for others), and there are also 2 pp suppliers in VIC.

Cheers

Around 1:30 a.m. today it came to me. I had problems with a printing like you are having. The rollers are set to deep and pull the ink off the type. Also, the trucks on for the rollers come be rolling free and the rollers at not doing their job correctly.

I agree that is not at all likely that the ink is penbetrating the sheet so much as to create such a stroing image on the tympan sheet. It does look like your tympan is not flat against the rest of the packing. It looks like ripples showing right in the area of your image. Are these ripples touching the image on the form even when not on impression? I would change color or apply new tympan and let the press run for a few minutes while not on impression or feeding paper and see if any ink transfers to the packing. If not, start impression and make certain every sheet feeds.

You can run two sheets of paper intentionally and see if the ink comes through the first sheet after impression. If so, then you do have an ink problem. If not, perhaps your press is staying on impression when it should not.

Ok I’m ready to pitch out a theory.

What if the type is greater than type high? I’ve never set Ludlow type before so I can’t comment on the lockup. It looks like it’s sitting up top of the leading. I guess it’s supposed to be like that. Or does the Ludlow require special low-slung leading?

The windmill would easily compensate for the additional height, and the roller rails would adjust to ink it properly. But the tympan, especially a sloppy one, would likely be inked when the press was closed with impression off.

That’s the only theory I can come up with. A malfunction of the windmill that was causing it to ink like that would probably prevent the press from working at all.

Any Ludlow type larger than its 6-point or 12-point body will need to be supported by blank slugs. Blank Ludlow slugs and standard .765” leads and slugs are the same height, however there are other heights of spacing material which should not be used to support Luldow slugs..
Some larger Ludlow faces may be higher than .918”, but that would be larger than 48 point.

Hey noftus/hungry - I do have a platemaker, but no we don’t make plates for others at the moment, sorry.

It is hard to accept that a paper intended for printing would allow ink to pass through it. Maybe you can test that by doing a drawdown of the ink on the paper: take a bead of ink on the tip of the ink knife, and with a firm pressure, squeegee it along the paper. If it doesn’t pass through the paper on a drawdown, passthrough is not likely either.
Perhaps there is some mechanical problem with the throwoff mechanism.