Original Heidelberg - setting rider roller

Anyone experienced in setting a rider roller correctly? We had to rearrange the form rollers on our Heidi and as a result the rider roller is out of whack. I’ve tried to set an even and “light” pressure where the rider and form rollers meet. But still getting a sloughing off of ink, especially at the bottom of the form. Not nice crisp type!

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I use our rider often and have never had trouble with it. I just position the from rollers at the top of the press, drop the rider in position, and tighten down the bolts lightly.
You mentioned your type looking sloppy. Are you running the rider on all jobs, or just when you see ghosting or for large coverage? I would not recommend using the roller unless the particular image calls for more ink coverage, or unless you see gohsting. Using the roller otherwise, can over ink on small areas, i have noticed. It is designed as an accessory roller for troubleshooting, not as a standard component for all jobs.
Good luck

Thanks for your reply natron. We have been running the rider on all jobs, but all of our jobs are mixed (small amount of type and large coverage), or are only large coverage. I took off the rider for this particular job, once I saw your message, and the type looked great! But the small image next to the type (yup, polymer) started ghosting and I had to put it back on. With some more adjustments to the pressure of the rider, I was able to get a pretty good result, though not perfect. Hmm.

I found your problem interesting for I have six rider rollers and never used one of them, so I checked my Heidelberg Manual to get information and I didn’t find much. A single paragraph:
POSITIONING THE RIDER ROLLER: The rider roller is not intended to distribute the ink, but to store ink where a “ghost” is likely. It is normally used on just such forms. The rider roller is of no advantage on ordinary forms. The illustration shows the rider roller being put into place. This is best done with the form rollers on the ink drum. Before placing the rider roller between the two other form rollers, it is recommended that the press be inked up. When the bolts are tightened, press rider roller lightly against form rollers. When removing the rider roller, it is also recommended that you remove the bolts and clambing nuts from press.

This manual is copyrighted and was printed in Western Germany from the original Heidelberg manuscript.

We nearly always separate text from large area designs in the plate process- We have found that adding a pass is less problimatic in the long run.

Updated. Hi

For best results, set the rider roller to contact only the LOWER roller of the forme pair. I learned this from a Heidelberg engineer and the London College of Printing

If you have solids and small type, turn the forme round if you can. Do not have fine type under a solid areas. You can then adjust the ink duct accordingly

Or, as has been said, do two passes

Hope this helps

Alan

Both Bev and alanshiffman give some good advice here.
I agree with Bev that it is often easier to run fine text as a seperate press run than a large image, even if they share the same color. This way you can properly ink the type (minus your rider roller), and then when you run your large area, add the roller and add a but of ink, or whatever is needed.
If you are running boxcar plates, you can even use the same plate, just cutting off the image, and then swapping back into position, and removeing the other part that has already been printed.
I also agree that, as alanshiffman says, you can position the form so that the type is to the side of the image, rather than above or below. This keeps them from conflicting with eachother.
Another reason to not leave you rider on at all times is that it may cause the form rollers to flatten or wear at the point of contact with the rider, when the press is left overnight etc.
-Natron

Updated. …Good point Natron-make sure you lift the rider roller at night to prevent flat areas caused by the pressure of the rider. Not so bad with rubber rollers, but a real problem with composition rollers.
Also, try litho inks as the pigment is a much higher concentration so colour density is maintained with less ink, so less ghosting or repeat marks…Letterpress requires 80% more ink than Lithography

To avoid ghosting, the forme rollers must be able to recharge themselves fully before the next inking-hence rider rollers, so set everything up to KISS pressure.

Some printers used to lock up another ink slab beneath the block/type, so the rollers inked both ends-like the vertical miehle

Make sure the rollers are set to type high and the tracks are free of oil. Are the roller springs tight or worn?

Alan