american flyer 1936 Hudson

[train18393]

I got my "new" 1936 Hudson mostly apart, however the field winding for the motor seems to be open. Rewinding it is no problem, but accessing it is. I think I can press the wheels off the axels. Are these drivers keyed or are the axel shafts quartered so I can maintain quarter when reassemblling. I have a NWSL quarter, but these wheels are probably to big for it so I plan on scribing a line on the axel ends and drivers to facilitate reassmbly. I suppose I will have to drill out the riviting on the frame spacers then drill and tap the spacers so I can get the frame halves apart for access to the field of the motor. Anybody gone this far into one of these before?

Thanks from a HO guy   Paul

[Nationwidelines]

In my experience, it is very unusual for the field winding to go bad, but it does happen.  I think I have only found 1 field winding bad in the 100+/- Flyer engines that I have repaired over the years.

The bigger problem I run into is deteriorating insulation on the wires going to the field from the bottom of the motor and any other wiring going to or from the motor.  Another issue, especially on these early Hudsons, is the reverse unit, which is a poor design.

The big problem you are going to have with rewinding the field is taking the motor frame apart and getting it back together.  The motor frames on prewar Flyer engines are pressed together on to studs that space the frame apart.  Some of these studs are hidden by the wheels.  There is no good way to take apart these motors and put them back together (so they hold).  

To answer your question, the drivers are not keyed and the axle shafts are not quartered.  You will have to eyeball it, when putting it back together.  

 

[Banks]

It is rare for a field to open.   Before you tear anything apart try reheating the solder joints on the field connections. I've fixed a couple of open armatures that way.

[train18393]

I can only find the wire from the field that goes to the reverser. the other one is nowhere I can see it. I am taking a resistance reading from the field wire on the reverser to the frame of the locomotive. I would assume that the other end of the field winding is grounded to that frame, hence the drivers. Would this be a correct assumption. I do see that the drive wheels are geared to the motor, but the rods are loosley screwed to the drivers, so the quarter must be close or they will bind. I think if I mark them with scribe marks that would get them close enough. This train was gifted by a very close family so the amount of work I would do on it seems to be required.

 

Paul

[Nationwidelines]

train18393

I can only find the wire from the field that goes to the reverser. the other one is nowhere I can see it. I am taking a resistance reading from the field wire on the reverser to the frame of the locomotive. I would assume that the other end of the field winding is grounded to that frame, hence the drivers. Would this be a correct assumption. 

 

Paul

 

No you would be incorrect in assuming that the field is grounded to the frame, as this would be a direct short.  The field should be insulated from the frame of the motor.

The wiring diagram would be, a wire from the center rail pickup to the bottom of the field, then a wire from the top of the field to the reverse unit.  From the reverse unit, there would be 2 wires, one to each of the springs/brushes on the motor.  The reverse unit would then ground one of the two wires to the springs/brushes to the frame, depending on which direction it is set to, and provide power to the other spring from the field.  

This is why it is important to check the insulation on the motor wiring, as a short in any of the wires to or from the field, would cause the motor not to run.  Additionally, as I previously stated, this early reverse unit is not the best design.

One thing you could do to check is connect the wire from the field to one of the brushes and ground the other brush to the motor frame.  This would allow single direction use, but be a good test of the motor.

I assume you have replaced the springs/brushes on the motor?  That is important on prewar motors, as the original brushes are not carbon brushes and the springs tend to compress over time and not provide proper pressure after 80 years.  The first thing I do when tuning up a prewar flyer motor is replace the springs and brushes.

 

NWL

[train18393]

What would the likley resistance of the field be, and is this a series or a parallel motor? I read a little bit over one ohm from the field wire on the reverser to the center rail pick-up. Also the insulation on the field was being slightly grazed by the armature. The winding does not appear to be comprimised, with no shorts between the windings, but the varnish is off the tops of the windings where the armature was striking it. I can't ask the previous owner as he is long deceased.

Thanks for your help, I am hopeing to get this working to put it around the Christmas tree this year and Invite his widow and new husband over for dinner. I think she would like that. She and her new husband are about 80, no exaguration.

[Nationwidelines]

Your resistance of the field sounds right, but I have not checked any of my engines.

Have you tried putting it back together and putting power to the motor?

[lionelsoni]

The field and armature of an alternating-current motor in a toy train is always wired in series (like prototype locomotive motors).

The motor speed is porportional to the armature voltage divided by the field voltage.  When, as in a parallel motor, the armature voltage equals the field voltage, the motor speed tends to be constant.  The motor either runs at that speed or stalls.

A parallel motor run on AC has the further problem that the field and armature currents, which determine the magnetic fields inside the motor, are not necessarily in phase, as they are in a series motor.

Either type of motor also has the problem that the alternating fields induce eddy currents in the magnetic parts.  This is mitigated by laminating those parts from thin sheets of iron.  Such a series motor is called a "universal" motor, because it can run on either AC or DC.

[train18393]

Thanks to your help I was able to get this 80 year old engine working. It won't change directions, and not a very good design for the reverser, so I wired around it.

Now if I can find a light bulb and a screw to hold the smoke stack on I will put the boiler on. Is there a lightbulb at the big box store that will work, or should I get one on the internet?

Thanks for all your help. It was not wasted on this predominatly HO guy. I do have many O Scale HI Rail engines and cars, but they are different than this antique American Flyer beauty. I even have 30s Lionel T rail track to run on.

Thanks again  Paul

[Nationwidelines]

Glad you were able to get it running.  Depending on the year, the reverse units are terrible and wiring around it is generally the best option.

Not sure about where you would find a light bulb at a big box store, as I haven't shopped for one lately.  It is a standard christmas tree bulb socket size, if that helps.