Heidelberg KSBA Feeding and Vacuum Pressure

Does anyone know how much vacuum pressure a KSBA air pump should be producing? If I disconnect the sucker bar, and hook a vacuum gauge directly to the pump, I consistently get 20psi with each stroke. Is that what it should be? I have a hard time getting this machine to feed consistently when running heavy stock (300gsm or so). Lettra is just about impossible and other heavy papers are difficult at best. I have completely disassembled and cleaned the sucker bar and suckers, that helped some, but did not solve the problem. I have also cleaned the air filters, valves in the pump, and tried different types of rubber suckers all to no avail. If I bring the pile height up high enough to feed, it inevitably will start picking up multiple sheets. Lower the height, and it will miss sheets. No combination of suckers, angle, air blast, or separator springs seems to make a real difference. I feel like the only thing remaining to test is the pump itself, unless I am missing something… .


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hi this suckers are the best i use them on gto, windmill and ksb in some cases you need to alternate them because they are very strong then of course regulate height, blow, tilt and sheet separators on the sides

image: 0001_SOF_gift_guide_99_GTO_heidelberg_suckers.jpg


Yes, I have tried those suckers as others have recommended them, but still not much luck.


Have you measured the vacuum at the sucker bar, you may have loss along the line to the bar.

I ran an SB for a couple years. One thing is that you are sometimes better off not running all the suckers at any one time. So, you may run a sheet with two open on the edges of the sheet, three in the middle and maybe a few others. I still do this on my Windmill. Better too little suction (missed sheet) than too much (doubles). At least the Heidelberg cylinders come with double sheet detectors.

Other means of coaxing stock included wedging the tail corners of the sheet or having a stick of reglet or 2 pica furniture at the lead edge to help get air in the stock. “Breaking” the pile by putting a bend in it (a 2 pica sticker at the front middle of the feed table) sometimes made all the difference in getting paper to feed. Also, make sure your blower is in good working order, the availability of lots of air is a good thing.

Maybe the sucker bar itself is leaking somewhere, but I am not sure how to test that… . I already replaced all of the rubber tubing, so that should be good.

I try to run with as few suckers on as possible, but something is just not right… . Thanks for all of the suggestions. I will keep fiddling with it.

On a windmill, I figure if I have enough suction to pull doubles, I have adequate suction and the problem is elsewhere.

I have a KSBA and solved a similar problem by cleaning the sucker bar I used a rifle cleaning brush and compressed air to get all the paper dust and other crud out. Every 500 hours of running is often enough for mine

Thanks, I will try getting a brush that fits down the sucker bar.