# 312 motor brushes



## astrobob (Jan 2, 2015)

Dear S gauge gurus,
I have a model 312 - 1946 whose motor has pooped out. I disassembled the engine
enough to dissengage the drive screw from the drive gears, removed the motor and
cleaned the copper commutator and brushes with very fine emory cloth. My query is
whether or not the brushes should be copper or carbon graphite. My brother-in-law
claims his ~1950 model has carbon graphite brushes, and that makes sense to me since
my Norelco shaver has carbon graphite brushes. It would seem that CG brushes would wear
alot more over time than pure copper brushes and cause the motor to fail. But like I said, my model has copper brushes that still seem to have adequate length to do the job so it puzzles me that my cleaning did not solve the problem. Is it possible that the original brushes had CG tips that are now completely gone? Not sure what I should do next to get this baby to run.


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## flyernut (Oct 31, 2010)

Welcome.. They should be carbon, and the part number is PA9603, a very common and easy to get brush. They're on ebay all the time, along with brush springs. Get both, brushes and springs, when you purchase them. They should also be of the shoulder type.When I clean my armatures, I put them in my drill press, and use a "bright-boy" to clean, polish, and take out any grooves. Make sure you clean out the small grooves in the face.Also,, make sure there is no hardened grease bogging things down. Grease will harden into cement, and make things not go.Make sure all your wheels are free-spinning too. I use rubbing alcohol in a spritz bottle, and soak the chassis and wheel axles to clean out any crude.You'd be surprised to find that hardened grease and oils will really stiffen up all the moving assemblies. Good luck, and again welcome.. PS We mostly here use Doug Peck at PortLines Hobby Supplies. He has everything you need for your flyers.:smilie_daumenpos:


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## Kwikster (Feb 22, 2012)

Copper brushes would mutilate a commutator face in very short order, even if oiled well. The carbon graphite brushes give excellent conductivity and wear resistance. The CG brushes may have a copper cast to them.

Carl


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## Nuttin But Flyer (Dec 19, 2011)

Both responses are excellent. The carbon brushes wear much better than you might think. In fact many of my steam engines from 60 years still have the original brushes. As long as they measure at least 3/16" in length, they are suitable to reuse. However, considering the cost of them along with new springs (about $3-$4), it makes sense just to replace both the brushes and springs. Save any old ones for spare parts provided they meet the required length. Be sure to clean everything as stated by the two members above and only add oil/grease to the proper areas -- nothing anywhere near the brushes.


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## astrobob (Jan 2, 2015)

Flyernut,
Thanks very much for alerting me to the ebay resources. After viewing all the available brushes there I believe that the correct brush for my 1946 train is PA10185 since neglected to mention that my engine is the SIT (smoke in tender) model. I purchased the brushes from T'ville Train and will let you know if the problem has been solved.


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## flyernut (Oct 31, 2010)

astrobob said:


> Flyernut,
> Thanks very much for alerting me to the ebay resources. After viewing all the available brushes there I believe that the correct brush for my 1946 train is PA10185 since neglected to mention that my engine is the SIT (smoke in tender) model. I purchased the brushes from T'ville Train and will let you know if the problem has been solved.


I don't know where you got that number for the brushes. All flyer steam engines used PA9603 carbon brush except for the 332DC,342DC, and the 346. If anyone else can confirm this, please let me know..


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## flyernut (Oct 31, 2010)

That # (PA10185), I believe is for the motor unit INSIDE the tender that drives the smoke unit. If you're looking for motor brushes inside the loco that drives the engine itself, I believe the # I gave you originally is correct.


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## Nuttin But Flyer (Dec 19, 2011)

Confirmed - What Flyernut has given for motor brush numbers is correct. The other may be for the smoke in tender motor.


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## flyernut (Oct 31, 2010)

Nuttin But Flyer said:


> Confirmed - What Flyernut has given for motor brush numbers is correct. The other may be for the smoke in tender motor.


During the next war, I want you in the foxhole with me,lol!!!!.. During night firing qualifications with the M-16, the 2nd lt. said something similar to me. I scored extremely high, and he stated he wanted me to go to Viet Nam with him...Thanks!!


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## Nuttin But Flyer (Dec 19, 2011)

Yea...we make a hell of a team -- like peanut butter and sauerkraut....


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## flyernut (Oct 31, 2010)

Nuttin But Flyer said:


> Yea...we make a hell of a team -- like peanut butter and sauerkraut....


Ya, but... who is who????:smilie_auslachen:


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## Nuttin But Flyer (Dec 19, 2011)

Since my wife thinks I'm a sourpuss, I guess I'm the sauerkraut...


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## astrobob (Jan 2, 2015)

Gentlemen,
You were correct that the brush PA10185 was incorrect - too small diameter and probably belongs in the tender motor unit for driving the smoke.
I also see the brush PA9603 on ebay, but many of them come with a compression spring.
The original springs for my brushes are not of the compression variety. They are torsion springs where one end of the spring is designed to force the brush against the commutator the way some door hinges work to keep the door closed, if you get my drift.
Now, this is not a problem since my original springs are still intact and functioning. I just thought I would get your comments before I make the ebay purchase of the brushes alone.


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## flyernut (Oct 31, 2010)

astrobob said:


> Gentlemen,
> You were correct that the brush PA10185 was incorrect - too small diameter and probably belongs in the tender motor unit for driving the smoke.
> I also see the brush PA9603 on ebay, but many of them come with a compression spring.
> The original springs for my brushes are not of the compression variety. They are torsion springs where one end of the spring is designed to force the brush against the commutator the way some door hinges work to keep the door closed, if you get my drift.
> Now, this is not a problem since my original springs are still intact and functioning. I just thought I would get your comments before I make the ebay purchase of the brushes alone.


Not a problem. Your 312 is an early variety. All my 312's have the other type of brush and spring. When you buy the new brushes, make sure they are the "slotted" type, not the shoulder type.The shoulder type use the coil brush springs, the slotted use the style you have. I've seen the slotted brushes used instead of the shoulder brushes, and I believe they don't do any harm. You need the slotted type. Hope this helps.


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## Nuttin But Flyer (Dec 19, 2011)

That's my partner.....


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