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Atlas SD50 Motor Replacement in Japan.


Kamome

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Kamome

I wondered whether anyone knows where I could get a replacement motor for an N scale Atlas SD50 in Japan.  I bought it many years ago on UK eBay for a pretty good price. The thing was an OK runner but eventually conked out. Taking the thing apart I discovered the motor no longer wants to turn under power. It's been sitting in my "maintenance projects" box for some years and I should really get the thing going again. 

 

I read somewhere that this chassis was actually a Kato made product. The one in question is identical to the one in this article about DCC installation.

 

http://n-scale-dcc.blogspot.com/2011/10/tcs-m1-in-atlas-sd50.html

 

The annoying part is that I can get one from Atlas, at least I think its the same, for about $35 but then once they add international shipping the cost escalates and as these things are probably used in other models, I could probably save on the whole international shipping thing.

 

Any help on possible model sites, electronics sites would be greatly appreciated.

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Kamome

If i connect the motor to a 9v battery, it doesn’t turn but if i turn the flywheel to get it started, it can then continue moving.

E881ED9D-A754-4A7C-9968-0D29EE9B0DFA.jpeg

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cteno4

Kamome,

 

have you tried blowing the motor out well with compressed air? Also can try to push a slip of paper between the stator and magnets, at times a bit of grit gets in there and can cause the motor not to get going on its own. Could be the brushes but I doubt the sell replacements, but they do look removable.

 

jeff

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Kiha66

I believe a lot of the atlas and kato motors are the same part just with different flywheels.  Atlas lists the SD50 motor in stock, but its the updated version with top pickups via a DC/DCC board instead of the side pickups from your model.

Removing the brushes and checking the state of the commutator is a good idea, if you pull the brass caps the brushes and springs pop out.  Be careful not to loose the parts, I've had a few bits go flying when I've had to remove them.

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Kamome
On 5/29/2021 at 11:34 AM, cteno4 said:

have you tried blowing the motor out well with compressed air?

Thanks for you help. I semi-dismantled the motor and gave the thing a good blow through with some compressed air. It didn’t appear to dislodge anything. 

 

Everything inside looks clean around the commutator and brushes that i can see. 

 

It’s almost as it there is a lack of power to one side to get the thing spinning but once it’s going it can keep momentum. As soon as i disconnect power, it stops and can’t restart itself.

On 5/29/2021 at 11:56 AM, Kiha66 said:

Atlas lists the SD50 motor in stock, but its the updated version with top pickups via a DC/DCC board instead of the side pickups from your model.

 

Thanks Kiha. I saw this and wondered whether it would all still line up the same. I also read on another forum’s thread that Atlas produced a slow, scale speed motor #498100 but these don’t appear in Atlas’ website so they may have been superseded by these newer ones. I might contact Atlas to confirm whether these are an option. The $35 is not the issue but the $40 international shipping on top is. I’d rather purchase another Japanese loco if i’m paying that money.

I did consider adding some other items to basket but the newer locos etc.. seem to have increased in price, certainly to more than us Japan modellers are used to.

 

My other option is finding a Kato one that would fit and changing flywheels. Are these things easy to remove?

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gavino200
Posted (edited)
29 minutes ago, Kamome said:

 

It’s almost as it there is a lack of power to one side to get the thing spinning but once it’s going it can keep momentum. As soon as i disconnect power, it stops and can’t restart itself.

 

 

I remember from my high school physics that electric motors need to draw a higher current to start than they do in motion. My teacher told a story of how the start current in some industrial motors was so high that they needed planning permission to draw it, and that they sometimes had to leave the motors running 24/7.

 

This is happening with a 9V battery? Does it also happen with a 12V supply? The copper strips in the picture look a bit dull. Have you tried scuffing/cleaning/polishing them?

Edited by gavino200
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cteno4

I wonder if one of the winding wires on one of the motor rotor coils is partially broken and giving some resistance so it doesn’t want to get turning but with momentum it will.

 

jeff

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The Stator Magnet looks damaged. If it's fractured then the poles of the magnet field is going to be divided.

The pull of the magnetic field is one sided

 

image.png.6ad2fe771b3b0dec38eabe8678c8dcdb.png

 

Inobu

 

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cteno4

Good eyes inobu! Bet that’s it. In addition any little fragments of the magnet can get stuck in tight places and bind things some and they won’t usually blow out.

 

jeff

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gavino200

If you blow up the image, it looks more like some paint or goo. Neither of which are good to have anywhere near the innards of a tiny electric motor.  

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Kamome

Thanks Gents, Your input has been an education, as ever.

 

So if the magnet is fractured, I assume it would be better to replace the motor? I'm guessing for something this small, stator magnets are not something easily replaced.

There also looks like some oxidation or something on the armature windings on one side too. Not sure if this is a hindrance or just a cosmetic 

 

According to information I've found. the model dates back to 2004 and I bought it from eBay for around £25-30 about 6 or 7 years ago. Its never been the best of runners but it might need to go back in the "to be fixed" drawer until I can locate a suitable donor or motor for it. Its slightly frustrating that these chassis seemed to have been used on a number of locomotives but yet motors are no longer commonly available, unless of course the newer atlas replacement is suitable.

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Take the motor to a train shop they might have a motor. The motor is $40 from Atlas

If the repair guy has a donor motor. $20 and both of you are happy.

 

Inobu

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Kamome

Thanks Inobu

 

Do you have any recommendations for shops that stock American outline in Japan?

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1 hour ago, Kamome said:

Thanks Inobu

 

Do you have any recommendations for shops that stock American outline in Japan?

 

Early Atlas engines were made by Kato. So one motor can be used in a number of frames. Most likely Kato

fit one of their motors in the Atlas frame. That is why I suggested taking to motor not the train. You want them to

match up the motor.

 

Inobu

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Kamome

Haven’t had a chance to check on train shops as yet but did get a reply from Atlas.

 

As suspected, the new motors don’t fit the old chassis nor does Atlas support parts for the older chassis other than what they have left on their website. 

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cteno4

One shot might be to get some good contact cleaners and blast it out well. At this point it couldn’t hurt. Will need to re oil the bearings after it drys out.

 

jeff

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Kamome

Thanks Jeff

 

Worst case is it still doesn’t run but i learn a lot more about motors. 😁

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