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Rewinding a motor for improved performance

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  • Member since
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  • 4,365 posts
Posted by Darth Santa Fe on Sunday, August 23, 2015 11:28 PM

If you have the time and patience.Smile Sometimes I experiment with motor windings because it's something different to do. It's not a fun project, but in some cases, the results are worth it to me. So far, the one I'm happiest about is the motor in my standard gauge American Flyer electric, which had a bad winding that wouldn't allow it to run properly.

In most cases I'll just replace the motor too.

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  • From: Huron, SD
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Posted by Bayfield Transfer Railway on Sunday, August 23, 2015 8:59 PM

Darth Santa Fe
Even with cheap can motors, that's quite a savings if you have the time and patience!

 

If it's your idea of fun, go for it.  However, I consider the value of my time also, and whether I have more time than money.  Rewinding a motor armature does not remotely sound like fun to me, so I'd rather spend the money.

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

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Posted by dstarr on Sunday, August 23, 2015 5:58 PM

Used to rewind slot car motors back when I was racing slot cars.  That was a long time ago.  If you used a heavier gauge wire, you got more torque.  Silver wire, if you could find, it was good, lower resistance than copper.  When you went to heavier gauge wire, you could fit fewer turns onto the armature.  This lowered the resistance of the armature windings, meaning they could draw more current, which means more torque. Fewer turns also means less back emf, which means the motor will try to go faster 'cause the lower back emf allows more current to flow into the motor, making it turn faster.    

   Now that we have can motors, with ceramic magnets, the factory winding works pretty good.  I haven't rewound a motor for many a year.

 

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Posted by Darth Santa Fe on Sunday, August 23, 2015 12:30 PM

sd80mac, to make sure I get the wiring from the commutator to the poles right, I first unsolder the wires and then find which ones lead where. Then I carefully unwind a couple poles, counting the number of turns (I do this for multiple poles for a consistent count), and measure the wire gauge with calipers.  Then I rewind the motor with fresh wire, making sure all the poles are wired correctly to the commutator. When I'm increasing the turns like I did for this motor, I'll use a wood toothpick to sort of stuff the wire in place and make more room, all the while making sure the windings are tight and consistent. It can be difficult!

The motor doesn't run any quieter, since motor noise is dependent on the quality and design of the commutator and brushes. However, it is stronger, more efficient, and has a slower, more realistic top speed!

Bayfield Transfer Railway, a spool of magnet wire with enough wire to do half a dozen motors costs about $4. Even with cheap can motors, that's quite a savings if you have the time and patience! However, if a motor is just poorly made, there's no saving it even with stronger magnets or better windings. That's when I go ahead and replace it with a high quality can or coreless motor.

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  • From: North Dakota
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Posted by BroadwayLion on Sunday, August 23, 2015 6:53 AM

LION buys new motors. Listen to your LION.

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by BRAKIE on Sunday, August 23, 2015 3:47 AM

Having rewound slot car motors,nooope think I'll pass on the "fun" part  and whimp out and buy a new motor.Surprise

Larry

Conductor.

Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

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  • From: Bradford, Ontario
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Posted by hon30critter on Sunday, August 23, 2015 1:04 AM

Michael:

Yes, from a purely economic point of view you are right. However, somehow I doubt the Darth Santa Fe has ever chosen the easiest or most economical route. You can't discount the fun factor, and there is something to be said for meeting a challenge head on.

Personally I have been inspired by his work, and I have actually managed to reproduce a couple of his amazing projects. The sense of accomplishment far outweighs the costs!

I mean no offense Michael, just my My 2 Cents worth.

Dave

 

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
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  • From: Huron, SD
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Posted by Bayfield Transfer Railway on Sunday, August 23, 2015 12:53 AM

MR used to frequently run articles on rewinding and balancing armatures back in the 50s and into the 60s.

Honestly, considering how cheap can motors are nowadays, I can't justify the time it takes.

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

  • Member since
    July 2006
  • 9 posts
Posted by sd80mac on Sunday, August 23, 2015 12:10 AM

Hello Darth,

Can you give a little more insight on the steps you took to complete the motor rewind? Also, does the motor run any quieter than it did before?

Thanks,

Donnell

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  • From: Bradford, Ontario
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Posted by hon30critter on Saturday, August 22, 2015 8:29 PM

Very interesting.

I don't think I'm coordinated enough to get the wire lined up consistantly.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    April 2007
  • From: Stevens Point, Wisconsin
  • 112 posts
Posted by arbe1948 on Saturday, August 22, 2015 8:10 PM

Back in the mid-60s, when I was racing slot cars, rewinding motor armatures was a great way of improving performance.  I can't recall the formulae, but I think fewer winds with a larger gauge wire would produce one result and more winds of a finer gauge another.  I do remember having to epoxy the armatures after rewinding to keep from "flying" the windings due to the much higher motor speed attainable.

Bob Bochenek

Bob Bochenek
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Rewinding a motor for improved performance
Posted by Darth Santa Fe on Saturday, August 22, 2015 7:50 PM

I had a weak running Athearn Trainmaster. Instead of replacing the motor though, I completely rewound it!

https://www.youtube.com/watch?v=TDCpOzql65k

It's not something I do a lot, but sometimes, I can really get some great results from it!

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