ink problems with t head

Discussion in '1-Color and 2-Color Offset Presses' started by kblack, Feb 12, 2012.

  1. kblack

    kblack Senior Member

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    Have you guy's ever had a problem with the horizontal movement on the t-Head and the plate not lining up. hear's what's happening. When i get the main plate set on the press. I put the plate on the t head and with a tight registration, sometimes i try and adjust the horizontal movement and i get to the end of the turn in or out and its still not enough to make it perfect. I move the plate one notch and then i can't adjust enough. Is it because i didn't punch the plate correct.? It seems like i have. Second question. Say i run letterheads for the university The same SD is on the top but maybe the main plate wordiing has changed. Should't i be able to run the same SD plate on the t head for a second letterhead and just change the main plate instead of wasting a plate. Doesnt seem like they line up correctly. Is it the way the file is coming from the rip. Just seems like i get two plates exactly the same. But they always have some differences. Just thought i should be able to save a plate when they have the same SD. thanks kb
     
  2. ziggy33

    ziggy33 Senior Member

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    Your using poly plates so I would say no gotta use a new plate cuz it might not come out the exact same out of your plate maker. The horizontal adjustment is a sloppy mess on every t head tight registration is very difficult lots of picking thru product once it's off the press. You should have a horizontal adjustment for your parent head so you can move both plates till they one right up.if that ain't working just punch your plates where they will work for you
     
  3. kblack

    kblack Senior Member

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    Yea i have been using new plates everytime. thought maybe you had some tricks to save some plates. But i figured thats why. Have no horizontal adjustments on the 9910, unless im missing something. just skew and vertical image.
     
  4. FFR428

    FFR428 Senior Member

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    Are you punching the plates yourself? Just be sure both plates are punched the same, you should have a side stop on the punch to butt the plate against. Punch the lead edge then flip the plate head to toe and punch the bottom. This so both sets of holes on each end are the same spacing. When you set and postion your copy on the main unit you should have enough side to side movement on the T head to properly fit the job. Be sure the ends of the roll of film are not loose or out of postion on the DPM. It is possible the horizontal adjustment on the T head is whacked. Also double check the plate clamps are re centered after each job. Have a talk with the prep guys making the plates. I'm sure they can have some variance when they setup jobs. Just be sure they are doing things correctly. I prefer to always make my own plates. Have them make you a target plate with 4 crosshairs in each corner. Then make 2 plates of the same identical image. You should be able to fit them right over each other. This might help you see where the errors are happening.
     
  5. ghuerth

    ghuerth Senior Member

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    kblack, 9910 has no horizontal adjustment other then moving the plate on the parent head for a side to side adjustment and moving paper side to side, FFR428 is on the right track. Whoever setup your T-Head sounds as if it was not targeted. Targets are good but a large image will be easier to line up.Design a file with a 1/4" or 1/2" grid 16x10, make 2 plates, punch them the same, mount them, and ink up, I prefer red in parent press and black in the T-Head, use 11x17 stock, don't be concerned on getting the lines straight on the paper, just line up verticle lines headclamp to tailclamp, then line up horizontal lines on gear side, if the lines on the operater side don't line up then you need further instruction. If they line up on the top of sheet but not the bottom then pack the T-Head and the bottom will line up also (called changing length of print) but if you still can't get the horizontal lines together, there are adjustments to be made. Choices are repunching the plate on one head to make it work or there are adjustments on the T-Head to line it up properly. Let me know what instruction you would like.
     
    Last edited: Mar 24, 2012
  6. kblack

    kblack Senior Member

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    Had problems again today so i ran two plates with a grid 1/2 inch apart on 8 1/2 by 11. Realize 11X17 would have been better but didn't take the time to change. It started off almost even on top with a little horizontal adjustment but ended up 1/16th of an inch off on the bottom. Couldn't skew the plate enough to make it correct. The main plate is square and straight its the t head plate that is off. I also ran a couple of different plates for our own letterheads which we have tight registration on top and bottom. Could make it close on top but it would be off on the bottom. Any good ideas or remedies. What do you mean by packing the t head? Its the horizontal line on the t head that is off the most.Thanks kb
     
  7. FFR428

    FFR428 Senior Member

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    You do know there's a adjustment on the T head to skew the plate right? It's at the tail end of the plate clamp and turning the screw in/out with swing the bottom of the plate left and right. Once it's parallel you dial it in with the horizontal adjustment knob.
     
  8. kblack

    kblack Senior Member

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    Yea, i know that is there and thats what i mean i cant skew it enough otherwise it is off on top. it just won't line up no matter what i do.
     
  9. FFR428

    FFR428 Senior Member

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    You can try to pull the lead edge of the plate a bit and stretch it down on the side you need it to move to then clamp the tail end. Also check the lead edge of the pinbar clamp to be sure it's not bent or installed wrong. You can remove the lead edge pinbar with a few screws. They are tapered ^ so as the screw turns in it centers in the hole. Be sure those are correct. I can't remember for sure if the lead edge of the pinbar is fixed or if they pivot. I think they are fixed on that model where they don't pivot when you skew the plate. Double check the holes are punched square which I'm sure you do. Just thinking out loud here of things it could be or to help. By far it's not the most advanced clamp but you should be able to fit jobs better than that.
     
  10. kblack

    kblack Senior Member

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    Yea, a tad bit frustating.when i put the grid on i made sure everything was centered. The horizontal and the skew for the plate. It was a little off verticaly but that was an easy adjustment. when i adjustated the horizontal to be even on top it was off on the bottom, so i left the horizontal alone and skewed the plate so the bottom would line up. when i did that the top was off and i couldn't adjust horizontal to make it all even. it was a small amount. So after i thought i had it the best i could. I ran two plates for our tight registrated letterheads and it was way off. Close on top but way off on the bottom.
     
  11. FFR428

    FFR428 Senior Member

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    Sometimes when you skew the poly plates the pinbar will just mush/oblong the holes and not move the plate. I used to put a piece of tape sometimes on the lead and tail edges of the plates to give them a little more body to cock/skew against the pinbars. I used thicker a 1/4" wide fiber type of tape it was almost like duct tape but clear. Also loosen the plate tension a bit so they can give and move easily. Hopefully you'll find something that works.
     
  12. kblack

    kblack Senior Member

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    yea, im going to take another stab at it tomorrow. i noticed it awhile back on some university letterheads, but the registration wasnt as tight so you didn't notice it, at least the normal person would't. You've been there before havn't you.:) But when i got our letterheads on there and you could really tell.
     
  13. ziggy33

    ziggy33 Senior Member

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    You should post pics of your grid while trying to line it up they sound some what interesting I wouldn't mind seeing your plate cylinder on the t head also just to see what your lookin at might be missing a snap ring or something somewhere
     
  14. kblack

    kblack Senior Member

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    I looked at the t head today and everything seems to be in tackt. What is a problem is that when i loosen the cyl. to adjust the vertical i can slide the cyl back and forth. If i adjust the vertical i have to pull the cyl back toward the operators side by hand to get it close to where it is suppose to be, before i tighten with the t wrench. It seems like when i put the t wrench in and loosen it and if i push on it a little the cyl slides away to the non operators side, then i have to pull it back and tighten up. any ideas.? kb
     
  15. ghuerth

    ghuerth Senior Member

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    Yes you should be able to run the same SD plate and just change the info plate. It just takes consistent vigilance to at least come close enough to drop in.
     
  16. ghuerth

    ghuerth Senior Member

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    I disagree T-head registration should be able to register dead nuts in all four corners of an 11x17. Do it all the time with metal plates, I need to try it with poly plates. I believe it should work if the T-head is setup properly.
     
  17. ghuerth

    ghuerth Senior Member

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    If you grab hold of cylinder on the head clamp and push to the gear side and pull back with movement that is a problem that needs adjustment. First there are 2 collars on the cylinder shaft which can be viewed at the cylinder gap look for a hole about a half inch in diameter and you should see a 1/8 allen screw that sets on a angled flat spot on the shaft, unlock and push cylinder towards the side you unlocked then tighten the allen. Repeat on the opposite end. You do not want the gear grinding on the frame. The other possbility is a set screw that can be viewed with the head swung away. Look from underneath the T-head on the side frame directly under #1 form there is an angle on the side frame with a set screw that could be loose.
     
  18. ghuerth

    ghuerth Senior Member

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    Follow directions on post #125. Line up lines on grid going head to tail. Does not matter if straight on sheet just line up lines. Now line up lines going from operator side to gear side. Line up on gear side. If op side does not line up, get a 3/16 allen and 1/8 allen, remove drip tray (if applicable) and look under T-head where the mounting brackets are and loosen the two 3/16 allens, next to these are the 1/8 allens. To lower the lines on the op-side raise the 1/8 allens to push the head up, to raise the lines lower screws to lower the head. Before making this adjustment loosen the three 3/4 inch hex nuts on the mounting bar keeping the center one finger tight. Cylinder pressure will have to be reset afer this adjustment. Don't forget to tighten the 3/4 inch hex nuts.
     
    Last edited: Mar 28, 2012
  19. plotter

    plotter Senior Member

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    sorry but for 11x17 with a tight fit, i would recommend getting a proper 2 colour machine, and not use a t head, there ok for quick 2 color work with little to no registration but why mess about wasting hours of time when you can run this job straight.
     

  20. ghuerth

    ghuerth Senior Member

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    Why would there be hours wasted? 10-15 minute setup when not in a hurry. I would not recommend running 4 color process with a maximum image but for spot color in all four corners, no problem. If I had the 100 grand or had the support work to make monthly payments on a GTO 2 color separate blanket press, sure no brainer, (recommend 5 color with perfector), but for spot color and tight registration on a press I already own with a T-Head no problem, even small DuoTones. Takes alot of consistant work to make those payments, thats where the decisions are made.
     
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