Impression leveling

anybody know if its possible to level the bed on a Heidleberg letterpress 10 x15 when I diecut or perf the bottom of the platen has more pressure then the top, I just loaded a die 8.5 x 11
at the bottom of the platen the first 1.5” cut through then nothing the rest of the way up the platen, I can pack behind the plate, but I need about 20/1000 at the top, seems like way to much difference, from top to bottom, I see two hex headed bolts on the left and right at the top of the bed where the chase latch lock is, are these to secure the bed? can the bed be adjusted? would really like to solve this once and for all do I don’t have pack up so much. ,

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According to the manual the packing needs to be increased and impression decreased. Not sure what the range is, 20 thou doesn’t seem crazy so I would try packing first and hope there aren’t other adjustments to make.

most clam shells will develop more pressure at the top when increasing pressure with the press. they will increase pressure at the bottom when increasing packing. a thinner plate might be in order for this job then using both impression and packing to balance pressure for the given job. i will try to illustrate this. 1 is using impression adjustment 2 is using packing/make ready. the Real Heid guys should chime in here as i am not one.

image: clam with impression.JPG

clam with impression.JPG

image: clam with packing.JPG

clam with packing.JPG

Modernman is right, the packing has to be right or your impression will be off. Dick G.

How many thick is the required plate for diecutting?
Sounds good I can only back off impression and pack up to see if it will balance

Well guys either way more packing less pressure same result
Less packing more pressure same result bottom hot,

So as usual I graduated the packing in 3 steps a 6/1000 each,(old offset plate) from behind the die approx 20/1000 at the top and were running with a few small patches.
So it seems that the bed needs to come forward 20/1000 at the top, to level off bed to platin,
Any old Heidi masters out there, know if its possible to adjust the bed?


Does this happen with a smaller die? you say the die is 8-1/2 x 11, the more rule you are trying to cut the more pressure you need, you might be maxed out. There are also die jackets that are different thicknesses, maybe a thinner jacket, or a thicker jacket, i don’t think you can adjust the platten. There is a shear collar in the back of the machine that breaks if there is too much pressure, could yours have broken? Dick G.

I pack to .040 (Jacket+packing). Any makeready needed is added to the back of the die. I haven’t done any kiss cutting with this set-up, but I am fairly sure that with careful makeready it would work.
I prefer to die cut on my Kluge. It is much easier to deliver a die cut sheet with out having pieces all over the floor and in the press.


Makeready on back of die not a good idea should be under plate on underlay sheet. The rule will be damaged safer to put scotch tape on die jacket if unable to do proper makeready. I will have to do a new vid on youtube or post some pics of proper set up when I have the time.

Hi, bilcom printing—

If I understand correctly, that you are cutting at the bottom of the platen, but not the top, I think you should _remove_ packing and _increase_ impression.

We use die-cutting jackets that are .030”. Ordinary die-cutting tends to need about .008” packing under the jacket; kiss-cutting, about .004”. The impression control sleeve is then at about the “1” mark, and pretty level.

Hope this helps, Brian

Mike is right about packing behind the cutting plate, however…..On my windmill the grippers start scraping the plate so I back the impression back just past the 0 mark on the impression lever and put one sheet of a manilla file folder behind the form. Then work the impression in till it just starts to cut and make minor adjustments. It usually works. Kiss cutting can be tricky as the stock differs. The very same job will run great one time…..and the next time the same job will cause problems because of the glue. Ron

I do most of my die cutting on my Kluge so makeready may be a little different, but I was taught to pack behind the jacket until most of the die was cutting well. Then makeready the die until it cut properly. I’m not putting 120# cover behind my die, just small pieces of onion skin or tissue in problem areas. Now my jacket doesn’t look like a war zone and many of my dies still cut well after 40,000 impressions or more. Final makeready behind the die has got to be easier and more accurate than under the jacket and a lot faster too.


If gripper scrapes plate during diecutting solution. Try using .927 cut rule you can use less packing under plate and more room for makeready. Many printers swear by .918 but do the math .918 will print on the surface of the sheet with type and if all is balanced a higher rule will and does work for diecutting. Another advantage is more room for matrix or surface makeready. True diecutting in North America is done mostly with with .937 cut rule however if your Heidelberg is not an actual cutter/creaser that is made for .937 don’t use it.

The gripper scrapes plate without anything underplate. It’s not deep and doesn’t present much of a problem except when placing makeready under the plate. It’s been working… far the White House hasn’t complained. And you know how particular they can be! Ron

as an old Heidelberg letterpress minder who has also done cutting and creasing may I suggest.: To enable you to reduce your packing to make the clamshell platan come together parall and therefore cut all over the same you can get your dies made in a lower height. most pro die cutters will be able to advise you.

Hello picaprince,

If your die is made lower, how could you reduce your packing? Wouldn’t the die need to be higher (as suggested by Mike Conway) or packing increased?

Just to add to the conversation I would agree with Brian Donnell. You need to remove packing behind the jacket and increase press impression. I work with .030 Bar Plate Boxmaker diecutting jackets and usually .900 cut rule in my dies. The packing I use is usually sheets of news print and or a tympan sheet type stock behind the die jacket.

There is the packing gauge on the right side delivery standard….not sure if your using that as a starting point or not. And on the impression handle when you adjust your impression from 0-1-2-3-4, when you are at 0 the platen is parallel.

Good Luck,