Heidelberg SBG perforating

Been running our Heidelberg SBG for perforating for 5+ years. Have one job we run 6 times a year. Blind perf on 70# text weight stock. Using a type heigh die with 2 perfs. running perpendicular to the gripper. Perfing to a die cut jacket.
Run length is 9000 sheets. have had to re-knife die 2x in last 12 months. Perf knifes flattening out. No scaring on die jacket.

Is this normal wear for a horizontal cylinder press. Have 25+ years experience on Miehle vertices and never wore out perfs.

Mike

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I have been running cylinder presses (miller TW, TY, miehle 29, little giant #6), platens c&ps kluges, heidelberg,over 40 years diecuting/scoring seems your probably over packing and not relizing it, unless you are using a perfectly new jacket with no marks on it, I would start there. Sorry I can’t be more helpful…

Machine has exact same packing under the diecut jacket as when we purchased it, no change there. I add sheets under the metal plate, under the chase to get the desired perf.

I usually notice mid run I need to add additional packing under the plate as the perf is getting weak.

Mike

The person that you purchased the press from, might not have packed the press correctly. Start over on the packing and read up on the correct amount of packing.

On working on my V-50 and C4, I found that the person that operated these machines before me, KNEW nothing about the correct adjustments.

After I read up on the correct adjustments things work 1,000 times better.

NEVER think the person that sold you the USED car only drove it to church and back.

Thanks Aaron. We had the machine checked over by a Heidelberg mechanic who works on the cylinder presses. We removed the die jacket to inspect the cylinder before purchasing the machine and the mechanic made sure the packing was correct.

I understand because this has a horizontal bed, unlike my V-50, the weight of the cylinder is resting on the perf. rules. I will re-check the packing is in spec. and talk to my die maker.

Mike

Also remember that on a cylinder you will need LESS packing for rule perpendicular to the gripper than for a rule parrallel to the gripper. That said the packing may be correct for one but not the other.

Paulm

use low height perfrules preferably sandvik if avaiable and increase pressure on demand should last at least 100 000 impressions also use the brushes so that the perforating stays papralell thru all the sheet i think i might have the sbg manual need to check if you want a copy┬┐

Thanks Phase4. I spoke to my diemaker and he suggested putting knife rule parallel to perf rule outside of paper area.
Knife rule will act as a barer.

Thanks for the offer on the manual, but we have one for the machine.

Mike

Since you have the ability to change the underlay (under the form), I would recommend that that be reduced and then brought up until you are just achieving a cut. If your machine is set up and running correctly, you should be able to get very, very long runs from the forms—well over 100K impressions.

If your mechanic is suggesting using cut rule as a bearer, then something is grievously wrong. The press is designed to run bearer to bearer in normal circumstances. Therefore, the bearers at the sides of the bed should be type high (or near enough to that). If you have a gap between the cylinder and bed bearers with the press under impression, then you need to address that issue.

Couple of other things that could be causing the problem: Are the teeth of the bed reversing gear and rack clean? If they are fouled, it will have the effect of lifting the bed (and eventually breaking it). The other is that there is a control on the operators’ side underneath the walk that is a lever which adjusts the “resistance to impression”. Unless you are running a lot of perf and cutting rule, the control should be set for light or medium at best.

I ran a SB for a couple years, and it was a good press, til they let some “rebuilders” after it. They were a supposedly national outfit, but I was aghast at how they handled the machine, and it was pretty much and is no good after their “rebuild”

It is not the mechanic who is suggesting the cutting rule as bearer, it is my die maker.

As it is set up now, we have the press set on medium pressure. I start with zero underlayment and slowly work up to cutting. I have noticed the change in the perf rule as I am running. I also do a lot of scoring on the press using matrix and am not seeing the changes.

one other thing that comes to my mind is i have done homemade or custom made die jackets over the years and the type of alloy used in different types of steeljackets does affect the hardness and also the life of the dies and the jacket itselft he last one i used that worked best was a steel die jacket with matte finish hope this helps