light inking 4 inches from bottom of sheeteven inking at bottom of 15 x 22 inch sheet

On my Vandercook Universal 1 the printing pressure at the bottom of the sheet releases (sometimes but not always) at 4 inches from the end of a 22 inch sheet causing the printing to be lighter. There seems to be no consistency in its happening. Sometimes the printing is fine and sometimes its light starting at 4 inches from the bottom of the sheet. Is there something I can adjust?


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22 thoughts on “Inconsistant inking on sheet”

  1. One more thing: My press seems to be printing very fine. David Seat’s setting of the roller bearings seems to be JUST RIGHT! Many thanks again to everyone for their patience and assistance. PRESS ON, Laurie

  2. Good News everyone! I think the mystery on why my press was coming up at the end of the form is solved. The gripper bar was hitting the positive lock-up bar as the carriage reached the end of the form. I rarely use the positive lock up bar and had totally forgotten that one is not suppose to use it on long forms. This info is usually printed on the lockup bar. Mine has all the lettering rubbed off. My friend here was examining the press with me and noticed that the lock up bar had dings in it that looked fresh. I went to look it up in the manual which says nothing specific but the picture of the bar shows writing on it that says: “Lock-up bar must not be used for forms that extend more than 19 inches from the head printing line because of gripper interference”. The carriage was lifting up as the gripper buttons hit the lock-up bar.

    The other issue that we found was that the gripper mechanism at the head was not working properly. I have always thought the grippers were not working right. We saw that the latch or “pin” was not going into the groove so the grippers were not opening all the way at the head, and not opening consistently at the foot nor were they opening on the way back to the feed board. This may not have anything to do with it but I am mentioning it for the record.

    So, the problem was something EASY and easily overlooked. I am so happy that it was NOT the roller bearings.

    Thank you to everyone for all your help. It feels great to have the support of all on the Vanderblog.
    I’ll let you know how it works as prints go by, Laurie

  3. Adjusting well-used bearings is very very challenging. In my experience the most careful setting to feeler gauges will still be off on successive passes. But small differences of one or two thousandths shouldn’t show the visible cylinder bear-off seen here. Worn spots might, if they didn’t always appear at the same place.
    I’d use an inside caliper and see if there are worn spots on the upper rail corresponding to the bear-off. If there is also a worn spot on the bearer, when the two line up there would be bear-off on heavy forms.

  4. Today I put a 21.5 inch long form of 18 point type in the bed of the press set on a 30 pica measure. With no inking I pull a proof with a heavier weight paper. The press is definitely coming off impression about 4-7 inches from the foot of the printing area. It’s inconsistent in how many inches it comes off impression from the bottom of the sheet. Mostly its at 4.5 inches. AND one time it printed the whole form perfectly.

    While I have determined that the roller bearings are not completely set properly—in watching them turn they seem to be in general acting as I said in my previous post, with the bottom front bearing on the opposite side of the hand crank NOT rolling going up or down the press and the bottom rear one, rolling both down and up the press.

    On the hand crank side the bearings seem to be rolling as they should although sometimes the bottom front roller bearing is not rolling on the way back.

    ALL YOU EXPERTS OUT THERE: Should I try adjusting the roller bearings?
    What is the prescribed settings for the bearings on a Universal 1 Press? .005, .007?
    Should they be set the same in the front and the back?
    Is it a good idea to use a feeler guage to set the bearings? I have access to a set of these.
    I don’t have a paper micrometer.

    Thanks for your help.

  5. I did a check of all the big roller bearings that ride the rails. Here is what I saw:

    On the side with the hand crank lever:
    On the way DOWN the bed the top roller bearings roll
    On the way BACK the bottom roller bearing in the at the front end NOT rolling. The other one in the back does roll.

    On the backside of the press:
    On the way DOWN the top roller bearings roll AND the BACK bottom roller bearing rolls.
    On the way BACK the top roller bearings roll and the BACK bottom roller bearing rolls.
    The front bottom roller bearing DOES NOT ROLL going down or going up.

    I took the plate off the gear rack and all the teeth were FINE. Everything was oiled. There was a little dirt but not bad. The brass bearings that the bolts go through were intact and came off and went back on with out any problem. There was PLENTY of oil on the whole mechanism.

    The cam follower is well lubricated and moves freely. It rolls on the rails of the trip mechanism going towards the foot of the press but it DOES NOT roll much as it goes back toward the head.

    I think everything is off because the roller bearings are not set evenly.

    What do you all think? and what do I do now?

  6. This press had its carriage removed to replace one of the bearings that was bad. I have a feeling that this may be of interest, but Dave Seat checked these, so I tend to rule that out. The reason I’d want Laurie to remove the trip rack cover plate is to see the condition of the bearings that the bolts go through–not to remove the rack. And to determine what level of lubrication there is on this assembly–the whole thing looks like it hasn’t seen oil for a long time. The backsides of Vandercooks, especially those up against a wall, often are neglected for maintenance, especially lubrication.

  7. If I was doing this, I would disengage the rack, first making marks to show the present timing of the teeth. Many other presses have timing marks made with a center punch, but for this I’d use a marker until I am certain of the timing. Then I would rotate the gear-and-eccentrics until I know the absolute topmost and bottommost positions of the cylinder. From those positions the correct mesh position of the rack would be determined by trial-and-error. If there is over-turning it might be an incorrect timing. But why that happens inconsistantly is more suggestive of Fritz’s idea of a worn cam follower (a worn or loose cam follower stud is possible too). The cam-follower on the gear rack is the most easily-ignored lubrication point on the old-style trip.

  8. Your photos didn’t link I think.

    However, at those two moments where it is rocking back and forth the 1/4″, look at the round steel bearing at the bottom end of the trip rack. This should be lifting or dropping or rubbing against something if you’re seeing it turn the eccentrics at all, this could be the culprit.

    Those clicks are happening as you travel through the trip paddles on the back. They’re the diagonal sprung paddles at the end of the press on the back. Each of them will have the same distinctive click.

    It doesn’t sound like you need to remove the rack just yet – Watch that bottom bearing as the press travels past the paddles and see what it is hitting. It seems like it’s rubbing against something that is causing the trip to turn when it shouldn’t be.

    The cover plate is on the left hand side of your previous photo with two hex-head screws in it – it is holding the trip rack against the press side. Don’t take it off just yet.

  9. Here is what I see as the carriage moves down the bed when set in long stroke.

    The crossbar spins ½ turn as it comes out from the head of the press and is complete about 1 inch from the head of the press.
    When it gets to the first trip flipper it makes a click sound and rocks about 1/8 of an inch but goes back to where it was. There is where I loose impression.
    At the second trip flipper it makes a click sound, rocks again about 1/4 inch and goes back to where it was.
    As the unit goes back towards the head of the press it rocks about ¼ of an inch goes back to where it was and then turns ½ or almost ½ turn (its hard to tell if its consistent).

    I tried to make a movie but its hard to do without an extra hand.

    I am waiting for a confirmation from Fritz about taking the gear rack cover plate off. Just want to make sure I know what it is before I do it. Here is a picture with a yellow arrow on what I think is the cover plate. Is it correct that one would loosen the nuts at the top and bottom of the plate to take it off?
    Thanks, Laurie

  10. The rack and gear are on the left hand side of your photo (round gear, straight toothed rack). The gear should align with a brass eccentric (round brass discs) on the inside walls of the cylinder, with a long steel cross bar that lies between your tympan and ink rollers, which has a matching brass eccentric on the other end. If you watch it as you roll down the cylinder, these eccentrics and the cross-bar will spin a half-turn as you start down the press, and a half-turn back on the return (this is the trip and print mechanics in action). This will all run in tandem with the rack and gear in your photo. This should be a very regular rotation at the beginning and end of the press bed, and nothing else happening anywhere in the middle.

    What you want to look for is this rack and gear, or the brass eccentrics and steel cross-bar shift, moving, or rotating slightly at the moment you lose impression. It could rotate forward or backwards and produce the same loss of pressure. Look on the rack and gear for a worn or broken tooth too like Fritz recommended.

    DON’T unscrew the rack and gear assembly in the photo (the rack is removable, allowing the gear to spin somewhat freely). They’re set together in a very specific pairing. I suspect Dave from Hot Metal could help out if it’s determined that adjustments need to be made here.

    Sounds like we’re getting closer…

  11. I don’t see how short-trip (the impression part of it) could raise the cylinder while still on the impression stroke. It lifts on the return stroke, no?

  12. Thursday evening: I took off the cover on the side of the press and with a friend took turns watching the mechanisms. I could not tell for sure about the rotations on the trip eccentrics and axle because I am not exactly sure what it is they are. I have a manual which shows a trip lever, a trip rack, a gear… When it prints properly the carriage feels tighter all the way down the bed than when it doesn’t print the last 4 inches. This happens randomly. The press seems to catch a little too when it prints than when it doesn’t .

    Is it possible for it to go into short-trip mode and stay stuck in that? and then it releases and prints a couple of times as long stroke and then gets stuck again? And, if this is so what do you do to fix this?

    Here is a picture of the side of carriage. There is some rubbing showing??? Maybe someone can tell me what I should be focusing on watching.

    Thanks, Laurie

  13. Sorry, I screwed up my post from last night and I didn’t want to be late for dinner. Vandercook lists for the Univ I a maximum form of 15×22, maximum sheet 15 1/4×24, and bed size 15 1/2×24. I’m not sure if the problem relates to too long of a form, packing, etc., but the cylinder trip rack, X–21774 that operates the X-10708 gear is where I would start. Early model Univ I presses had a wimpy gear rack with thin sides that often distort and to the point they will bind up. Later models had a much beefier, redesigned gear rack. The gear the rack turns that makes the cylinder go on and off impression also wears out and that may be inducing slop in the impression on some or all of the teeth. Wear may not be readily apparent. Then, the cam follower X-2726 on the bottom of the gear rack may have developed a flat spot and that could affect impression, so that may need replacing. That whole cylinder trip rack assembly takes a beating, and because it is covered, is often ignored when the oil can gets passed around. I suspect the problem is there.

    fritz

  14. One more thing, I cannot read Fritz’s comment as there was some kind of attachment to it that took me to a whole other web address and would not let me access the Vanderblog. His comments do not show up on my Vanderblog page either. Many thanks for all your comments and help, Laurie

  15. forms using the whole sheet ALL THE TIME. You can see what kind of prints I make on my web site (ensatinapress.com) This problem cropped up a couple of months ago. I originally thought it was the inking rollers not being down low enough. I had Dave of Hot Metal here at Thanksgiving and he checked out the whole press. Since I thought it was the inking rollers and he gave it an overhaul I didn’t even mention it. BUt we did not do systematic checking that the sheet was printing all the way down the bed of the press. Also, it’s not something that happens with every print. The Racks, rails and teeth are clean. The press is set on a long stroke.

    The only problem he found was with the bar that holds the oscillating roller system has some kind of problem that he sent a movie to Fritz about. Fritz and I were supposed to connect about this but since its been a longstanding problem and the press still seemed to print fine I wasn’t rushing till after the holidays.
    After Dave was here I noticed that the problem seemed to be about and inch or so lower on the press sheet than it was before he came.

    So now what? Laurie

  16. A short-trip only affects the gripper release.
    First you need to determine whether the fault is with inking or impression. You are at the limits of the press, and in fact I’d have guessed beyond the 20″ deadline.

  17. To me this looks like the trip mechanism is possibly rotating for some reason, either over-rotating, or possibly turning back. Next time you are printing, watch the trip eccentrics and axle (I don’t know the part number… Paul?) located directly behind the oscillating ink roller. It should make a half rotation as it goes into Print, and rotate back at the end of the press as it goes back into Trip.

    The other big thing to look at are the bearers. Are all your rails clean? Are all the teeth on the racks clean? Is there anything wedged in between the bearer and rack on the end of the press?

    Is the press possibly set to a short-trip?

    Do you usually print forms this far down the bed? Is it possible this has been a long-standing problem that you have never experienced?

    Tell us more!

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