I’ve got a 32-28. As I run the press, the screws that hold the form rollers at the correct height become very loose, causing the rollers to drop and strike the type improperly.
Viewing the pictures right and below, screws A and C go almost all the way through the
carriage [bearing bars] to bring the bottom of the [them] up against screw B. It seems that it’s screw B that comes loose, which then allows the other two to loosen and cause the rollers to become unaligned.
I’ve followed the operator manual in order to get all of the inking rollers parallel and at the right heights in respects to each other as well as the form. The two theories that I’ve been able to come up with are that the pressure of the rest of the inking system is great enough to cause the screws to loosen; or, the action of the carriage moving down the length of the pressbed is violent enough to shake them loose. I’ve set the limits of the action of the inking carriage so that it seems appropriate, but, well, I’m at a loss. I’ve spent too many nights perfecting the roller heights and then watching them quickly (like in 15 passes) come out of alignment. I’m wondering if other folks with similar machines (232?) have similar problems. I think this carriage system is sort of rare.
Any help is very welcome. Thanks for your time!
I would like to note that some of the set screws (I’ve got several carriages) do seem to have been worked over pretty hard with a too-small screwdriver. I use a medium-sized one and it seems to be the right fit.
I’ll try swapping out the set screws, as well as changing the carriage again. I’m quite certain I’ve got the blocks set up correctly, but will make damn sure before I print again. Might I need to tap it for a larger set screw and get a new screw? The two set screws I’ve got in there right now seem to be completely undamaged, but I’m concerned that either they’ve worn in a uniform manner, or that the frame has done the same. I’ve never encountered a problem like that, but as I understand it, this can happen with these machines. Right?
Thanks again and in advance.
I’ll add that sometimes users destroy threads from over-size screwdriver, and screws from under-size screwdriver. I don’t know if that is the case here, but I know the previous owner of this particular was an art school, just the type who uses a limited set of tools beyond their design.
Too many times I’ve been asked to look at a problem Vandercook and found with it a set of metric car tools, a claw hammer, a crescent wrench and a can of red 3-in-1 oil as the entire tool set. How can you spend thousands on a press and almost nothing on adjustment and maintainance?
Eric just about covered it all, except that this model and the 232 have the added horizontal adjustment, which was added to ensure that the rollers are parallel to the ink drum. Like the height adjustment this should be made before tightening the lock screw.
Yeah, the central screw is a setscrew which SHOULD prevent the adjusting screws from moving. The setscrews can wear out, and there can also be obstructions which prevent the setscrews from sitting against the block. First thing to try is tapping the hole and using a die on the screw to make sure threads are intact throughout. Some users have replaced the setscrew with an Allen setscrew but that could lead to over-tightening and distortion of the frame.
Those holes are oil-holes.
Are you sure you have assembled the bearing blocks correctly? I’ve seen many incorrect configurations. The upper half of the block should be unthreaded, the lower block threaded, and generally the blocks are stamped with numbers so you keep original pairs together.
I’m sure somebody more knowledgeable than me will chime in shortly, but in the meantime…
The middle screw is the set screw. I’m not sure how it works, but tightening that is what keeps the other two screws from moving. You say that the bottom piece (which is the roller bearing block) is being pulled up to the middle screw. In my understanding, that screw should be going into the block.
At least that’s how it is on the 219, 4, 320 and other presses. Now that I’m looking closer at your picture, I see what looks like two allen wrench holes next to the outer screws. Is that a hex screw? If so, have you played with that? Not being familiar with that press, based on that picture I’d say maybe the middle screw actually does affect the relationship of the bearing block to the roller frame, while the two outer roller height adjusting screws have set screws, which in your case are not being tightened, or are worn out.