Changing engine operation

jim29t Apr 15, 2013

  1. jim29t

    jim29t TrainBoard Member

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    I have a Marklin 2-6-0 #8895 which runs backward in relation to other engines. How can I change it's operating polarity?
     
  2. Garth-H

    Garth-H TrainBoard Supporter

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    That is an odd one as the way the motor is mounted and the power is routed to the motor brushes this should not happen. It means that at some time either during assembly or afterward the magnet poles on the motor have been rotated 180 degrees so they have been swapped. I do not know if the top half of the motor is keyed in place or free to rotate but it needs to be rotated 180 degrees around the armature, so after removing the screws that hold the magnet part of the motor onto the chassis try not to lift it clear of the end of the armature shaft as that could damage the brushes at the other end. You should be able to hold the armature down in place so the magnet does not lift it as you pick it up a bit the magnet par up to rotate it The only other way is to cross wire the pick up to the brushes which if you electrically challenged is tough to do and ensure you don't have a short. The other answer is to contact the Glen and Sandy Stiska in Florida and let them sort it out for you or someone else who does Marklin repairs.

    regards
    Garth
     
  3. DPSTRIPE

    DPSTRIPE TrainBoard Supporter

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    The 8895 should have a motor assembly similart to the one in this drawing. At some point, someone popped off the magnet housing and put it on backward. Just remove the two screws that hold the magnet housing on, rotate the housing 180 degress and replace the screws. It will run the same direction as your other locs after that.. The magnet housing is item 7a in the drawing.
    Dan S.
     

    Attached Files:

  4. kimvellore

    kimvellore TrainBoard Member

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    Dan,
    I think rotating the housing would not change the direction of rotation, if you think about it the motor spins inside it so rotating the outside is actually doing nothing, to change direction you will have to flip both magnets inside the housing.

    Kim
     
  5. rvn2001

    rvn2001 TrainBoard Member

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    I have encountered the same problem that Jim has. Rotating the housing with the magnets inside fixes the direction problem. I've had to do it several times with used locos.
     
  6. DPSTRIPE

    DPSTRIPE TrainBoard Supporter

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    Kim,
    Rotating the housing changes the polarity of the field with respect to the current flow through the armature. I have had a couple of used 8803s with the same problem.
    Dan S.
     
  7. jim29t

    jim29t TrainBoard Member

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    Thanks so much. I have had the problem with deisels but never with the smaller engines. I will try the rotation and see what happens. Thanks again
     
  8. jim29t

    jim29t TrainBoard Member

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    I rotated the housing, as you suggested and it works fine, same direction as my other locomotives. It even seems happier running in this direction.. Thanks to all of you that took the time to address my problem. Jim
     
  9. kimvellore

    kimvellore TrainBoard Member

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    Dan,
    That makes sense, you are rotating it with respect to the brushes... Now that I had some sleep I can understand...

    Kim
     
  10. Garth-H

    Garth-H TrainBoard Supporter

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    glad you made it work

    regards garth
     

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