Kato Coreless Motor failure?

Randy Clark Feb 9, 2019

  1. Randy Clark

    Randy Clark TrainBoard Member

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    Has anyone had to replace the Kato Coreless Motor in a FEF3? If it does start up in forward and the loco stops, it usually will not start up again in either forward or reverse. It is DCC with a Tsunami Decoder. When the throttle is opened up, the sound increases but the motor does not rotate unless you give it a kick start on the shaft. The moto does feel like it has rough spots in it resulting in vibration.

    The whole loco is completely apart but the motor is still connected to the tender and dcc controller. It is definitely not a mechanical bind.

    Thought it might be BEMF settings but the vibration in the coreless motor leads me to think the motor is shot.
     
  2. JoeTodd

    JoeTodd TrainBoard Member

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    Need to hit kato up on this one. Sounds like a manufacturing issue.
     
  3. MK

    MK TrainBoard Member

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    Use a multimeter and see if you have one of the windings broken or shorted out since you said there is no mechanical bind.
     
  4. BarstowRick

    BarstowRick TrainBoard Supporter

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    I wondered out loud...once upon a time...how long it would be before we would hear something negative about this new technology. Coreless Motor, how is that possible? Was the question of the time.

    I own one and have never had any problems with it. I mean how much trouble can it give me if it's never been out of the box. Hunnh?

    Not that I had any doubts. No good deed goes without being punished. No new invention goes without it's trials and error's. And, Nothing lasts forever. If it's man made it will break but most often it can be fixed. Or something like that.

    I do hope it's something simple and you find yourself with everything back together and your locomotive up and running again.
     
  5. Randy Clark

    Randy Clark TrainBoard Member

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    FYI, I have 3 and I run the stew out of them. This is the only one I have had acted like this. In it's current condition, the locomotive is completely dis-assembled down to nuts and bolts. Bare Frame. The motor is still connected to the tender and dcc is functioning. As I said earlier, the motor will not turn over until you give it a nudge either in forward or reverse. If it were not sealed, I would be looking for foreign material in the motor causing a mechanical bind. This was originally determined by removing the boiler shell and nudging the flywheel with a small screwdriver.

    I'll talk to Kato on Monday and see what they know. Frankly, IMHO it's just worn out. If I can get any specs from them on the motor, I may look for a stronger motor. Found some last night that are the same dimension and voltage that are used in drones. But there is the risk of overpowering the mechanism and stripping gears and throwing side rods. I don't like using Bull Frog Snot because it provides so much traction. I am afraid will transmit too much torque to the side rods.

    Next thing I will do is hook it up to straight DC and see how it acts. We'll get her fixed.
     
  6. Hytec

    Hytec TrainBoard Member

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    I don't know the technology of a coreless motor. However, your saying that it must be spun to start rotating indicates that whatever the design is to overcome static inertia has failed. With older motors, this may have been special windings that gave the armature a kick to start rotation, but then were isolated electrically or magnetically by the run windings when the motor got up to spreed. Yes, it definitely sounds like a manufacturing defect which should be covered under warranty.

    I recommend not fooling with it any more because you may cause something else to happen that Kato could say that you caused the failure. Doubtful, but possible.
     
  7. BarstowRick

    BarstowRick TrainBoard Supporter

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    Sounds like the old fashioned HO scale locomotives I had. Athearn, Tyco, and Revel. I would have to nudge the motor to get it to start. Hit it with some electrical contact cleaner and it would be good to go...for awhile. Pretty much a thing where the oxidation would build up on the brass contacts.
     
  8. Hytec

    Hytec TrainBoard Member

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    Rick, I'm not sure that would apply to coreless motors. Aren't coreless motors brushless? Or am I confused with another technology?
     
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  9. BarstowRick

    BarstowRick TrainBoard Supporter

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    True we are talking old technology compared to new.

    Not suggesting this as the resolution. From what I've seen the motor is sealed and you could hit it all day with electronic tuner cleaner to no avail. It just reminds me of the same problems.

    However, I would check all brass contacts and see if everything is touching. Sounds like the OP has done that so...where does he go next.

    Contacting Kato, maybe they could send him out a new motor and that makes sense to me.
     
  10. John Moore

    John Moore TrainBoard Supporter

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    Last edited: Feb 10, 2019
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  11. Doug Gosha

    Doug Gosha TrainBoard Member

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    The only real difference between a conventional motor and a coreless motor is that the coreless motor has no metal laminated core on which the windings are wound and the magnets are inside the windings. The windings are kind of just floating in air. There are still a commutator and brushes.

    Doug
     
  12. Doug Gosha

    Doug Gosha TrainBoard Member

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    The one disadvantage of a coreless motor is that a coreless motor can't take high current very long because there is no metal core to absorb the heat and the glue holding the wire winding assembly together can soften and the windings can fly apart, wholly or partially. Of course, modern adhesives have partly ameliorated this.

    It sounds like the subject motor has had a winding or windings break or come loose from the commutator. The same symptom occurs in a conventional motor with the same cause.

    Doug
     
  13. Randy Clark

    Randy Clark TrainBoard Member

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    Well, STRIKE ONE! Called this morning and service/parts was taking a day off. (Or doesn't work Mondays at all) Back to the phone tomorrow.
     
  14. Randy Clark

    Randy Clark TrainBoard Member

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    Did get to talk to Paul. He has helped me with things in the past. Good guy. Try again tomorrow.
     

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