stoping printing presses at high speeds

Discussion in 'Heidelberg Printing Presses' started by jmt, Jun 30, 2010.

  1. jmt

    jmt Senior Member

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    i have been trying to get our pressmen to stop stoping there presses at high speeds by opening guards or hitting the emergency button just to make up a few secs for washing blankets or plate changes . I have alrdy had to reset timing of the feeders on our cd pm and sm but they still don't listen they say thats how they where taught to stop the press .I am trying to get a list of problems these kind of actions do to the presses not to mention the wear it does to the press and reducing their life span .so please just list a few things you know happen by doing this and i want to show management that these actions are costing money and down time.

    thanks in advance.
     
  2. RichardK

    RichardK Senior Member

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    I would think that the first thing to wear out would be the brake...electromagnetic or otherwise.

    It's good practice to slow the press to crawl speed before hitting the stop button unless it's an emergency.

    I'd flip my lid if any of our guys thought that that was the correct way to stop a press...it shows no 'sympathy' for the mechanical elements of the press and can only lead to premature wear of drive components.
     
    Last edited: Jul 1, 2010
  3. mrheidelberg

    mrheidelberg Senior Member

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    I think a lot of printers say to themselves "it's not my machine ...... who gives a ****" ........ unfortunatly !!
     
  4. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    The "Emergency stop" method of bring the machine to a halt is not the preferred method by any means. The machine should be brought to a soft stop by shutting off the feeder air or the feeder and letting the sheets run through so the machine can come to a stop slowly. If the press is just idling the stop button on the press and feeder consoles (Not the "E stop" button) should be pushed to come to a slow stop.

    As mentioned in the post above when the "E-stop" is hit the brake comes on and brings the press to a hard stop. Depending on the size of the machine this is a lot of steel with built up rotational kinetic energy you are trying to stop instantly. In the case of an XL105 the machine makes 8 revolutions after a hard stop before the brake can bring it to a full halt.

    The risk of premature wear and tear far out weighs the few seconds saved stopping the press by opening a guard or hitting an "E-stop". My recommendation would be to advise against it.
     
  5. exheidmech

    exheidmech Senior Member

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    I think its kind of strange that you have to reset feeder timing due to hitting the estop at high speeds. Are your guys stopping the press while it is feeding sheets? Most of the time, guys are hitting the estop or opening a guard after the last sheet has been delivered, the machine is slowing down, and the feeder is off. If the feeder is off there is no possibility for the feeder timing to slip. As far as wear on parts most of the parts are already mentioned, the only one I would add to the list is gears. Gears are made of only cast iron, they are not hardened so everytime the machine is hard stopped this put an unbelievable ammount of stress on the teeth of the drive gears. That being said I have never heard of gears breaking because of a hard stop.
     
  6. Meny

    Meny Senior Member

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    If this is what they where told and they listen to what they are told , tell them that from now on when they come to work in the morning they should run in to the entrece door without stopping as this is the right way.
    Next , lock up the door and see what they feel.....on the forehead
    next , tellk them that it is your press and if they want to go on being employed they must do what you say !
    the way they go = damage
    if you are the boss , you must attend to it
     
  7. jmt

    jmt Senior Member

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    to funny .I just usually say would you slam on your brakes everytime you stopped your car. just image the damage you would do to your own vehicle.
     
  8. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    Is that why I have to keep replacing tires every 2000 miles? That probably also explains why my radio does not work from all the coffee that has spilled on it.
     
  9. NotAGooner

    NotAGooner Senior Member

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    E stops are exactly that, E stops, only used in an emergency, by way of which I am thankful after getting my hands caught in the rollers of an MOZP.

    Can also be used to prevent damage to press, i.e. a rag falling into the rollers etc
     
  10. lildaddy50

    lildaddy50 Member

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    first time (warning) second time (unemployment line)

    Rod
     
  11. JOHNYPRINT

    JOHNYPRINT Member

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    If a manager needs advice on telling there staff not to do something that could be bad for the machine, maybe a new manager is required
     
  12. print101

    print101 Senior Member

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    I would go absolutely nuts, first of all they dont respect the machine, and then they dont respect the supervisor.

    1st Warning, 2nd Warning, Final Warning, Out.
     
  13. axeman06

    axeman06 New Member

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    GTO question

    new to the forums here and was reading older posts, anyone have an idea on why the only way to stop my GTOZ from idle (such as when i'm washing up) is to open a guard, or hit the emergency stop? Pressing either of the regular stop butons doesn't do anything unless it is feeding paper.
     
  14. mqgpress

    mqgpress Senior Member

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    Hey Axeman - That's just the nature of the GTO, no motor stop buttons supplied like there are on CPTronic machines.
     
  15. axeman06

    axeman06 New Member

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    Thanks for the answer, glad to hear i haven't been beating up the press for four years for no reason.
     
  16. spike

    spike Senior Member

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    there are lots of good pressman looking for work turn off feeder stop press
     
  17. jmt

    jmt Senior Member

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    i dont mind them stopping the press at idle its stopping it when its still at 12000 hr!

     

  18. FSA

    FSA Senior Member

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    jmt
    three broken gears, $7500 plus 8 day of down time ! ! the machine never did top speed again, had to sell it. The operator was warned, he didn't listen, less than a month he was gone. It sent a message to the others, and I had to run it till a replacement was hired, it was a good 40" 6C Komori till that day. Mrheidelberg hits the nail on the head when he stated that "it's not my machine who give a **** ". Today there is alot of good unemployed operators to choose from, find someone who care.
    FSA
     
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