I am under the impression that the only way to increase impression on a KSBA is to build up the packing. I am printing quite a large poster with a large printed area. To get the kind of bite that we know our client wants I need to put a bit of packing under the tympan. Most all of it is soft packing. The issue is that the tympan keeps ripping after a few impressions. At first I thought it was because the base was too close to the front of the chase so I moved it back an inch and a half and even then it tears at the same spot, right behind the teeth that hold the tympan. I also moved the packing back so that it’s not all right at the front. I was wondering if anyone had any ideas as to why it would do that and is there any way I could adjust the cylinder for impression?
I’d appreciate any kind of help for this newbie to the KSBA.
Well if anyone else runs into this issue I finally figured out what it was. You do need to wrap the majority if not all of the packing over the entire cylinder including in the front where it grips the paper.
Puzzling through this and based on my own experience, which really is limited to a couple of V-36 Verticals and a Kelly “B”. The closest I’ve come to running a Heidelberg was running several KORD and KOR presses. Keeping that in mind——
it seems to me that the cyliinder gear and the bed gear are fixed relative to one another. With all the packing either under the bed or the cylinder, the ratio of the length of contact between the teeth might vary, resulting in scuffing of image or as mentioned, actually tearing the tympan.
So this kinda made my eyes cross, and I did the “Four Period Test”. This was on a V-36 on which I wanted to print process color. I locked up a 12pt period near each corner of the chase, and tried various packing combinations, trying to get balance between the cylinder and the bed. The result, several hours and (truth to tell) a couple of beers later, I could run four different colors and register was, if not perfect, at least way on the quality side of “commercially acceptable”. I guess the whole exercise affirmed to me the need to keep the circumference within range of the bed gear tolerance by packing evenly. I apologize for the length of the answer, but after all this time, I can now feel that it was for more than just one process job! Life is good….