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EF57

?magnetic resistance in Tomytec power unit?

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EF57

I got a Tomytec power unit TM10R for my Eizan Hiei excursion car (the one that looks like an Oldsmobile sucking a lemon, for those of you who remember the Edsel).  When I turn on the juice (Minitrains controller), it won‘t start in either direction.  Pushing doesn‘t help, but turning the driveshaft of either side from above does the trick—then it runs beautifully and silently in either direction.  There is no resistance in the gears, but I do seem to feel a magnetic, not mechanical,  resistance against the shaft starting to rotate which must be overcome.  No contact problems.  Sound familiar to anybody?

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EF57

it is not a short, since it runs perfectly once started.  But once I bring it to a stop, it wont‘t start again and makes a very  high-pitched hum, which continues until I spin the flywheel, where I do feel some kind of resistance, not mechanical.

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inobu

seems link a motor issue on the commutator or issue in the pole winding. It could be the motor sat in one place low voltage applied for a long time. 

If the commutator is burnt in one spot then no power is applied to get the motor started. When you turn it to a good spot it starts.  

Inobu.

 

https://www.electrical4u.com/images/PMDC-motor-construction.gif

 

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Kiha66

One test to see if the issues is the motor alone or your specific throttle is to use a pure DC power source to test.  Try using a 9 volt battery and see if the train can run.  If it does than you know the problem is it does not play nice with your throttle pack, if it does not than the issue is likely in the motor itself.  

 

 

Edited by Kiha66

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cteno4

Every time one of the coils goes past a stator magnet you will get a little resistance. When you turn the motor shaft you can feel little thunks.

 

i would first try kiha’s suggestion of pure dc to rule out powerpack issue. It may be an issue of a partial burned coil or even a poorly wound coil that just does not give a good turnover to get going but once there is momentum it runs. Odd one.

 

jeff

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EF57

Thank you, that sounds like a likely analysis.  It‘s definitely not the power source.  Guess there‘s nothing I can do, huh?

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cteno4

So you tried with something like a 9v battery?

 

jeff

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brill27mcb
On 5/1/2020 at 4:01 PM, EF57 said:

Thank you, that sounds like a likely analysis.  It‘s definitely not the power source.  Guess there‘s nothing I can do, huh?

 

No, they do not sell Tomytec motors as spare parts. If you are a tinkerer, you could substitute a different aftermarket small motor, secured to the chassis with silicon caulk.

 

Rich K.

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beakaboy

Inobu probably has correct assumption, but I once had an older Atlas unit that did a similar thing. I found eventually that one of the magnets on motor had come loose and would move and bind armature. The magnet seemed to move around when stopping and restarting, so sometimes it would be fine. Just a thought!

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EF57

Yahoo, problem solved!  Having got the chassis running by the aforementioned spin of the armature, I turned up the juice all the way and it ran fast, then broke out and shifted to superfast!  Since then it’s been working perfectly.  I guess a metal or plastic chip/particle from manufacturing had gotten in where it didn’t belong and was creating resistance and this knocked it free.  I feel great!

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cteno4

Great! Have fun with it now!

 

jeff

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