Team, please advise on roller height adjustment for the Vandercook 4? Thanks.
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There are two parts to the roller assembly. The upper part with the oscillating drum and riders; and then the lower part with the form rollers.
Remove the upper assembly, and store it at the end of the bed while you make the adjustment.
You’ll need a flathead screwdriver- actually two- as you’re going to adjust screws which lower/raise the form rollers in relation to the bed, and another single screw which is actually a locking screw.
So, you’ll see on either side of this assembly are three sets of screws. Looking at it ACROSS the impression cylinder/inking system, you’ll note that the middle screws are different from the other two outer screws; this is a SET SCREW.
1. First, locate and loosen BOTH set screws.
2. raise or lower your form rollers the desired amount using the other two ADJUSTING screws.
3. Remember to TIGHTEN both set screws again before continuing to step 4.
4. Replace the rider rollers. Believe it or not in some machines the form rollers may not drop down to their intended height without rider rollers atop them. Wear, bends, etc can cause this, and I had a hard time getting an accurate read of the form roller height with a No. 4 that I used to have without the rider rollers/oscillator installed. Something about that made sense to me, as well, so I always made the adjustment and then reinstalled the rollers.
If you have a type high roller setting gauge/lollipop, obvsly you’ll wanna employ it here, and hopefully you already know how to do that- if you don’t, just ask.
Hope this helps!
Oh, another tip- I used to assume all rollers would just print well if I set them to type high. I no longer take this for granted; wear and other factors get in the way of this.
So my usual MO is actually to lock up a base if I’m doing plates and take some scrap pieces of photopolymer plate, stick them in a small grid on this base, and then raise the rollers up until they do not ink these pieces.
I start with one roller, lowering one half, and then the other half, trial and erring the inking until we see it come into balance. Once I have it balanced, I note the screw position and then raise it up two whole turns (720 degrees), then I lower the other roller and do the same. After balancing roller 2, I can 720 degree turn roller number one down and do a test inking, then check to see that everything is still well.
As much as a pain in the ass as the older style inking system like this can be, I at least found the flathead screws to be nice as they give you an indication of position. Which is helpful.
Hello Haven Press, MANY THANKS! This is all very, very useful. I’m spoiled by the ease of said adjustments on our Universal 1… the whole carriage set up on the 4 feels awkward and uncomfortable to me, but your advice should get me sorted. Much appreciation.
While I have you, there is one other piece of the 4’s design that has me puzzled… the distance and height of the grippers in relation to the feed-board is significantly greater than the Uni 1. It’s not nearly as easy to feed. Is this typical?
I would say, No, it is not typical. If the distance of the gripper stops from the feed table out too far, perhaps the cylinder has been removed and replaced one tooth out of place.
On your second question, is the height of the grippers the problem, or is it rather the height of the gripper bar? There are adjustments for both of these available to you.
Mine I had to actually shim the feed board UP in order to accommodate the cylinder basically bumping into/lifting it when the carriage was at the feed board position.
If you loosen the feed table at it’s base you can shim it up a bit with some steel strip material or something that will allow you to tighten it back down without allowing for any wiggle.
I too have a Uni-I now, and couldn’t be happier.
Jhenry, that had been the case, but I was able to get the gripper bar back in to its proper, vertical position. Before, it was over rotating, so that when the carriage was in its rest position, it sat with the bar well underneath the feed board.
The height of the gripper bar is the issue, when being fed, the sheet has to be pushed at a downward angle, and then persuaded to go under the grippers.
I think the cylinder is still not aligned correctly. The gripper bar itself should not sit exactly at 12 o’clock at rest, rather the hem of the packing would, which results in the correct clearance and angle for stock to feed under the gripper buttons.
The rest position is maintained by the bumper springs behind the carriage pressing the cross-rod against the cylinder check cam wedge. Weak or missing bumper springs, broken check cam springs, these could change rest position too.
A Vanderblog search could help.
dexteritypress, from your description, it seems as though the feedboard is not level, or is set too high.
Nickel Plate Press, that was sorta the issue! One of the contact welds is broken on the underside of the feedboard, causing it to pitch back… I’d been looking for a way to make adjustments with little luck, then I saw the busted piece. Easily fixed, then all good! Many thanks.