no impressions in the middle

ahh. I’m at wits end with my pilot. It wouldnt ink properly and after 2 nights of trying to adjust and level the plates- I am still stumped at the fact that I was able to get beautiful deep impressions (without ink) at all 4 corners (of my 5x7 poly) but completely blank in the middle.

Any reasons why the middle part is not getting any impressions? could my platen be warped? the boxcar base is fine, poly plate is fine. I cant tighten it any more because the bar wont work (it hits the spring)

Any input will be appreciated. thanks — sorry for the bad image - it’s just to show you that im getting an impression at the edges

image: photo-5.jpg

photo-5.jpg

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The form may be too large. Does this occur with a plate half the size?

yes -same problem with my smaller poly plate as well. I have 9x12 press.. this plate is only 5x7

What does your make ready look like? My friend had a similar problem with PP and after she changed to a mag cut mounted on wood the problem went away. Do you have any that you could try?

This looks mostly like a makeready problem to me.

Try this:

You should temporarily drop the lettra stock and put in a sheet of smooth office 20# copy paper, then pull an inked impression. Put the printed page on top of an unprinted page, jog to center, then push a pin through the center of the page and poke another hole about an inch away (any direction, doesn’t matter).

Remove the pin, pick up the printed sheet, cut away the well inked areas, recenter on the other sheet using your pin holes, and using just a touch of spray tack or an extremely thin layer of paste, to mount the cut sheet on the full sheet.

LIft your top tympan bail and put under your existing packing next to the metal platen. Take into account the position of the gauge pins, or your makeready will be high on the press, if needed use scotch tape at the top to position on the platen. Put your tympan bail back down and pull another impression on office paper, repeat, as needed until the impression evens out, adding the cut down sheets only to the original makeready sheet, not adding a new one each time. Once done, go back to your lettra stock and try an impression.

Any time you start getting near the size where your press is maxed out on form size, you start to see what you’re seeing here. You also see it on old platen presses where the platen or the bed has become dished from wear. You can check that with a straight edge across the bed of the bare platen and a flashlight…

In either case, the solution is very careful makeready. Once you have good makeready, if you still aren’t getting an ideal impression, you can change stocks, change inks, or change presses…

Hope this helps,

Alan

Pilots are 6 x 10. I have trouble getting even prints from much smaller forms than yours on mine.

Widmark- yes, I mean 6x10 - thanks!

Alan- Ill try this tonight- thanks so much!!!

A 5x7 plate on a 6x10 press *and* deep impression is an invitation to trouble. That plate is likely just too large for your press. Even with larger and heavier platen presses a guideline of 1/3 of the chase area is a more reasonable expectation…for your press maybe 4x5. Additionally you still need to go through a thorough makeready as described.

You may be experiencing something we referred to as “cupping”, the inability of the plate or more likely the base to hold up, beyond a certain point. This I have experienced with wood base and no other yet. Everything is going fine and looking good and all of a sudden one impression is good and the next, the base has failed. Good luck with that. This drove me crazy one day, of course with a job that had to be done instantly sort of. I never proceeded to push polymer plates beyond a certain point ever since.

Just want to send you an update — seems like everything’s out of whack.. I decided to test print a smaller plate (2x2) and it didnt ink properly nor gave a deep impression.. ive tried both hard and soft packing - didnt work as well.. Ive also tried leveling the platen (either the top had too much impression, bottom with no impression — vice versa).

Calvinc - when I first got the press - it printed other plates beautifully but now, with the same plates - there is no pression… it seems like my pilot lost its strength..

I dont know what i’m doing wrong —- so frustrating..

im using oil based ink —- should I add additives to make it more “fluid”?

Seems you might have several different problems.
The first one is probably that the cut is to big to run on a Pilot. Two you may have over tightened the cut in the chase, causing the cupping described above.
Three, when you tried to level the bed did you use any of the techniques aptly described in other threads on Briarpress. I know it has been well covered.
Fourth, if the bed is level and you are still not getting ink in the center of the form you ink rollers have probably sagged or swelled on the ends and shrunk in the middle. The roller issue comes into play if you can get impression with heavy packing and no ink.
Overall it is like you need to reset your press and rollers as if you just got the press.
Good luck,
Steve Varvaro