QMDI Clunking during plate wash

ronrogers1234

Member
Joined
2010
Posts
9
Geo
USA
Our QMDI makes a clunking noise when it goes to 800 on the speed control during plate wash. It does not do it at the slower speed goes away as soon as it speeds up. During the clunking the press is actually jerking It's as if the motor is stopping and starting. It happened after we moved the press.
 
It sound slike there is an issue with the Hall Encoder which is built into the main drive motor. The encoder is optical and is what tells the brushless motor when to fire the next bank of magnets to provide rotation. There is a disc that has 5,000 lines on it to produce signals that the optical sensor reads. When the press is running at speeds over 2,000 iph or so the lines move fast enough that the sensors do not have time to do anything if one of the lines is not read. When you slow the press down the sensor can see the break in the line and tries to stop the press causing the bucking you see and hear. As soon as it passes that part of the disc with the bad line the press tries to run normally again until the bad spot comes around again.

Since you have just moved the press I would check the cable that attaches to the main drive motor with the the black or silver round connector that has the knurled ring you screw down to hold the cable in place on the motor. It may not be attached correctly. If the whole fitting moves on the motor the cable connects to, it could be twisted when the cable was screw back on causing damage to the wires in the motor. (I have seen this happen before.)

If this does not fix the problem the complete motor will need to be replaced.
 
    • Hi Paul,

    I think you are spot on there, i thought this could be the cause and have seen it before but couldn't for the life of me think what the remedy was.

    Regards.
     
    mrheidelberg,

    The remedy is definitely a new motor if what I stated earlier does not work. I have pulled apart the Hall sensor before to see if I could clean the sensors themselves or see a bad spot on the incremental disc. Unfortuantely, neither worked, not too mention it is a terrible pain to pull this all apart. By the time you paid someone to try and fix the encoder you could have bought a new motor and had it installed.
     
    Where is located the Hall encoder and disc that has 5,000 lines ????
    There is way to fix this anomaly ???
     
    It's only dust on the bars of the encoder, which Paul has mentioned. You could clean it with the press air, but access is a bit complicated, because of cover and the propeller. There is also danger to unscrew the wrong screws (sealed with the red ink), than the motor would had really be changed.
    Jan
     
    Yeah, right !
    It so easy to say that.
    For you guys from Heidelberg always it s easy just to replace parts, without to try to fix something.
    I ask again .
    It s possible to fix this anomaly without replacing the main motor ?????????????
    Thank you !!!
     
    You could try what was mentioned in post number 6, just to see what happens.
     
    jan said:
    It's only dust on the bars of the encoder, which Paul has mentioned. You could clean it with the press air, but access is a bit complicated, because of cover and the propeller. There is also danger to unscrew the wrong screws (sealed with the red ink), than the motor would had really be changed.
    Jan
    Click to expand...

    Can u explain with a little bit of details, or schematic ????
    Thank you Jan!!!
     
    Hi Ognen,
    I didn't even noticed that you joined this thread, I think you are a bit impolite. I'm not used to communicate with my customers via forums.
    You know my e-mail and the phone. I haven't heard you for the long time. Recently asked you for help for Orange Print, but no response from Ognen. Now you are in hurry and impatiently.
    rgds
    Jan
     
    Be sure your Blanket washer Is pushed in all the way.. =(:confused:
     
    Are you Ognen, or Lasko?
    Seems your e-mail address has changed.
    I didn't get any response at least from Ognen since few years.
    I will send you something in 2-3 hours.
    Have to finish my accounting, I'm late as usual.I hate it
     
    • dimaster said:
    Yeah, right !
    It so easy to say that.
    For you guys from Heidelberg always it s easy just to replace parts, without to try to fix something.
    I ask again .
    It s possible to fix this anomaly without replacing the main motor ?????????????
    Thank you !!!
    Click to expand...

    I am not sure that you read my post completely earlier, but I have taken apart quite a few of these hall encoders. The first ones I took apart were just to see if I could repair them. None worked properly afterwards as you need special equipment to set them, this equipment is not available to the field technician and quite frankly would be a waste of time. By the time you had everything set back correctly the cost would have been prohibitive and a new motor would have been less expensive.

    The rest I took apart were to train field technicians as to how they worked.

    I would take mrheidelberg's advice.
     
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