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Rattling shaft in electromagnet

  1. Feb 23, 2013 #1
    Hi to all, i'm new to the forum and forgive me if i'm not in the right place.
    I have a drag knife sign making cutter which uses an electromagnet to drop and raise the knife. The shaft that runs through the coil rattles/vibrates and although the machine cuts ok it drives me mad. Obviously the shaft needs to be free within the coil but is there a way of stopping the rattle - grease maybe?
    Thanks in advance.
  2. jcsd
  3. Feb 23, 2013 #2
    Try grease or a sideways force via a padded spring
  4. Feb 24, 2013 #3
    If you have access to the Armature ( the part in the solenoid that moves) - Try wrapping it in parchment paper - to fill in the gap between it and the coil.
  5. Feb 24, 2013 #4
    Thanks for the replies, i can get to the armature but do you think grease or parchment paper affect the performance of the solenoid? Al
  6. Feb 25, 2013 #5
    It is likely anything you do can affect the performance - I am not a big fan of grease as it collects dirt. The parchment paper can just be removed if there is a problem.
  7. Feb 25, 2013 #6

    jim hardy

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    Science Advisor
    Gold Member

    Is this 'rattle' a buzz at line frequency?
    if so, look for something that prevents the last few thousandths of an inch armature travel. A small air gap will cause high current and buzzing in an AC solenoid.

    Disregard it it's a DC solenoid,.
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