Heidelberg Platen feeding
Hello everyone.
Yesterday I ran my first negs, made my first printing plate and inked my Heidelberg for the first time. It all went well for a first go but I had some problems.
I now have a renewed respect for those that have mastered this machine, I found it physically quite exhausting and was quite emotional by the end of it, I had to go for a drink and cigarette ( I stopped smoking 13 years ago ).
My main problem is that the suckers sometimes don’t pick up any paper at all and then they pick up two or three sheets at a time with me making no changes in between. The stock is Fedrigoni’s 300gsm Old Mill in 30x24cm press sheets, I’ve flicked through the pile so they’re not stuck together.
My blowers on the feed table are clean, I’ve adjusted the angle of the suckers so they hit the paper flat and when they do pick up a single sheet it prints and is delivered fine.
Any suggestions to help me achieve a consistent feed?
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I’ve started with a simple single colour A6 Christmas Card.
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make sure your filter is clean, its located to the left of the suction trip in the hose. this thick paper is a bear to run, it will take some playing around to get it to work.
yes I agree make sure your filters are clean and there is a valve on the top of the pump make sure this is fully in it will give you more air, if I run ncr or thinner stock I turn it out. I find running thick card it is best to get plenty of blow into the pile to seperate the sheets and lift it to the suckers, to get more blow there is a valve control lever on the right hand near the side table, turn it downwards to adjust. I see you have a roller lock on your machine use this until you get consistent feeding. try using 2 seperator fingers instead of all of them and try using fewer suckers just enough to pick the sheet up also I sometimes put a piece of 12point reglet under the card to alter the angle of it, you can start by placing it under the backend it that does not work move it forward until you find where it will, you can adjust the blower position as well by the lever at the side of the feed table, it is trial and error really until you find the settings that will work, also I have found a slight angle with the grippers is better than flat on for not getting doubles, fanning is a good idea and adjusting the speed of your machine can make a difference to a good blow, I have been off work now for 2 months with my leg in plaster should not be long now and I will be back on the platen, cant wait, good luck, John.
Thank you both for some excellent advice, I tried again this evening with much more success, I think what was happening was that the feed table was rising too quickly and I kept lowering it manually, when it was high the paper stack pushed on the suckers and they grabbed more than one sheet, when it was low it didn’t grab at all.
This evening I worked out how to slow the rise of the feed table to match the speed the sheets were being removed from it, I also screwed in the valve on the pump as you suggested John and reduced the sensitivity of the sucker trip.
All this together got it feeding smoothly
dickg: Is the filter you mention actually in the hose, is it the knurled chrome bit in the bottom left of my first photo? If so I couldn’t work out how to extract it.
One other question, can I leave the Van Son rubber based ink on my press and plate overnight if I’m in the middle of a run or does it need to be cleaned off and reapplied? I ask because I’ve found it quite difficult to match the previous days Pantone exactly.
I appreciate the assistance, I’m in the French Alps and I’m a long way physically from anyone who uses a Heidelberg for printing that I could ask.
John I hope the leg repairs quickly!
Glad you are up and running and yes it should be alright to leave the ink on your machine but I would just wipe the ink off the plate, the filter is inside the knurled aluminium bit it needs to be unscrewed and the filter is inside that,you will be amazed how much paper fluff can be inside if it has not been cleaned for a long time, I hope I am not stepping on Dickgs toes with this answer, looks a nice job keep it up, regards, John.
Not at all John my answer was a lot confusing, sorry., that filter sure picks up a lot of dust.
porous stocks like the cotton rag and rew pulpboards are not easy to get feeding , sometimes running with one of the sucer bar suckers left off the sheet and partially open can help stop multiple pick up. There is always mileage to get the feeder runing with no impression or inking wwhen using these stocks to reduce spoilage . The wedge under the back of the pile in the feeder is always a good start , practice and a bit of lateral thinking will get you ahead in no time . Spelling poor due to too light on the keys !!
I owned a Heidelberg Platen and they are a great machine, but it has many steps before printing.
Do you have a manual?
Remove the chase and run the press without any image, to get the paper feeding correctly.
It has taken me many test jobs to get my 12x18 Little Giant Cylinder press to feed correctly.
100% it not the press, it the adjustment on air, suction, and timing of the stack of paper coming up.
Running a press ,is like learning to drive, you have to learn what makes the machine operate correctly.
yes on both sides of the feeding table, you can use small plates of metal to hold the sheet of paper, so you will pickup only one, and you can bend it up or down.
Just wanted to say thanks for the advice here this week, I printed my first simple cards, after getting my feeding working everything went much more smoothly.
I did nearly damage the press when I forgot the bit of metal furniture I’d put under the feed pile to raise it’s edge….and the suckers picked it up and handed it to the gripper. Fortunately I was watching and stopped it going into the platen!
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Those are very nice! Next time you can tape the furniture to the feed table so the suckers won’t pick it up.
Yes I definitely will, those suckers are more powerful than I thought.
Update:
I have found that I can solve the problem of the suckers picking up two sheets by putting the Sheet Slow-Down Finger on the Sheet Steadier Bar, this has reduced my misfeeds massively.