Need Advice - American Flyer Steam 312 problem:

[Latenite]

A friend asked me to repair an American Flyer 4-6-2, Model #312.

He runs it now & then, and  while he was running it recently,

it began to smoke from the motor area & he asked me to take a look at it.

 

I know very little about AF engines, but there seems to be quite a bit

on the Internet, which helped. This is a 4-plug engine, so I  jumpered the

two center pins on the back of the cab & applied low AC to the outer pins

as several sites suggested to bypass the reverser.

 

The motor ran fine, and after about 20-30 sec, what I believe are the Field

Coils (??) on the top of the motor began to smoke gently. I stopped.

 

The armature turns freely by hand, and the motor began to rotate at about 6VAC.

It seemed to run smoothly considering its age. During the 20 sec.test, the engine

Was only given a max of 8VAC  I could see the brushes sparking somewhat.

 

It doesn’t seem to be binding, but I am not  experienced on these engines.

Shorted Field coils? Any suggestions?

 

If there is nothing that I can do, can anyone recommend a decent repair

service for this engine/motor? My friend is very sentimental about it, and

the engine is in excellent condition, so he would very much like to keep

It in good shape.

 

My Thanks –

[AF53]

This might help fix the problem. There might be too much dirt on the commutator.

http://www.thortrains.net/flyermanual.pdf

This is a link to the manual for this era of trains.Start with page 56 in the manual and go over the next 5 pages. It could help you solve this problem.

[lionelsoni]

A good way to check for shorted field coils is to run the motor on DC.  Shorted coils act like a shorted transformer secondary, with the rest of the field as primary.  With DC, there is no transformer action; so the shorted coils should not heat up.

[Major]

Back in the early 60's when I was in high school I had a field that went bad and I rewound it.  The fields are not hard to rewind and I am still running this 312 engine today with no problems.  Just measure the length of the windings you removed and rewind with the correct size and length of wire.