Why the Double Motor Winding on the Lionel #50 Gang Car?

It allowed Lionel to use a more simple SPDT switch on the slide instead of a DPDT which would have been required with a single wound field.

A couple of years ago I bought a #50 from Da Bay, which requires periodic tune-ups to keep running smoothly. In the course of performing those tune-ups so many times, one end of one of the sets of magnet wire finally broke off – and of course, it was part of the ”inner” winding so I spent some time unwinding the “outer” winding, bringing out a new length, and rewinding everything back together. Problem solved.


I always unsolder the field wires from the brush plate as the first step of disassembly.  As you learned the hard way, over time the wire gets brittle and is easily broken. By unsoldering the wire you can avoid most of the flexing that causes the wire to break. This goes for all motors, not just gang cars.

ADCX Rob posted:

It allowed Lionel to use a more simple SPDT switch on the slide instead of a DPDT which would have been required with a single wound field.

Agreed - but that DPDT switch could have been very easily implemented with a second set of contacts on the slider plate and would seem to have been the preferred engineering.  It would seem a manufacturing process hassle to spec a motor that requires winding twice, so I was curious if anyone had heard of (or would hazard a guess at) the logic behind the decision.  For example, was the slider plate used in a previous product and they wanted to reuse existing tooling?

Agreed - but that DPDT switch could have been very easily implemented with a second set of contacts on the slider plate and would seem to have been the preferred engineering.  It would seem a manufacturing process hassle to spec a motor that requires winding twice, so I was curious if anyone had heard of (or would hazard a guess at) the logic behind the decision.  For example, was the slider plate used in a previous product and they wanted to reuse existing tooling?

Weren't both field windings applied at the same time?
That's how the fields on double wound Lionel motors always have appeared to me.

A DPDT switch built into the reversing slide would have required more bits and pieces as well as more hand work to assemble. Plus everything would have needed to be smaller, and therefore more delicate and more sensitive to exact placement during assembly.

Somewhere in my stash I have a couple of spools of magnet wire that has two conductors bonded together. Not something Lionel did, but someone must have had a use for it. (so far I haven't found one)

C W Burfle posted:

Weren't both field windings applied at the same time?

Yes.

When you are making something in the quantity that Lionel made the gang car, every piece counts.  Every operation cost money.  I bet they made several hundred thousand gang cars over the years. 

Lionel must have liked the double winding method, as it shows up in their low-end locomotives with manual reverse switches well into the MPC era.  ;-) 

Mitch 

C W Burfle posted:

Weren't both field windings applied at the same time?
That's how the fields on double wound Lionel motors always have appeared to me.

Hmm.  I'm not familiar with the #50.  But I've fooled with a lot of MPC stuff with double-wound fields.  I'm pretty sure only ONE of the fields is in use at any time (connected to ground through one side or the other, of the two-position reversing switch.)  When converting one of these locos to a 3-position e-unit, the service station manual says to use only one winding, and leave the other disconnected.

Out of curiosity I tried connecting the two fields together to see what impact it had on operation (thinking this would be similar to rewinding the field with more turns.)  Top speed was reduced, but slow speed performance was worse- the motor seemed to have less starting torque.  I guess it's about balancing the resistance of the armature and field.  Bottom line, at least for the MPC locos, I'm almost certain that only one field is in use at a time.

Ted Sowirka posted:

Out of curiosity I tried connecting the two fields together to see what impact it had on operation (thinking this would be similar to rewinding the field with more turns.)  Top speed was reduced, but slow speed performance was worse- the motor seemed to have less starting torque.  I guess it's about balancing the resistance of the armature and field.  Bottom line, at least for the MPC locos, I'm almost certain that only one field is in use at a time.

Right.  One field is wound for clockwise operation, while the other is wound for counterclockwise operation.  Run both at the same time, and you're essentially cancelling them out.  

Mitch 

ADCX Rob posted:

C W Burfle posted:

Weren't both field windings applied at the same time?

Yes.

Depending how it's read, this question could be about how it is actually wound, or how it operates.

I think they are commenting on the winding method. (clarification?)

The OP refers to inner and outer windings and they should be wound together, side by side, not in layers. The bonded dual wire would make a rewind easy I'd think.

   Another advantage to CW's soldering is the annealing from the heat will likely help prevent the wire from work hardening.

I guess I could have been clearer in my earlier post when I wrote:

"Weren't both field windings applied at the same time?"

I was referring to how the wire was wound on the bobbin (coil form), not how they were energized.
as Adriatic wrote:

I think they are commenting on the winding method. (clarification?)

The OP refers to inner and outer windings and they should be wound together, side by side, not in layers. The bonded dual wire would make a rewind easy I'd think.

That is what I was thinking when I purchased the dual bonded wire. Unfortunately it is the wrong gauge. To be clear I will restate: Lionel did not use dual bonded wire.

Right.  One field is wound for clockwise operation, while the other is wound for counterclockwise operation.  Run both at the same time, and you're essentially cancelling them out.  

Physically, both wires are wound in the same direction, side by side. But electrically they are hooked up as Mitch wrote.

Adriatic posted:

ADCX Rob posted:

C W Burfle posted:

Weren't both field windings applied at the same time?

Yes.

Depending how it's read, this question could be about how it is actually wound, or how it operates...

Big difference between "applied" & "energized" or "powered".  I read it right.

The reason for the double wound field is to simplify the switch to reverse the motor. There is an inner wire on each side of the coil form and an outer wire on each side of the coil form.  The inner wire from one side and the outer wire from the other side are connected together and then connected to one brush holder. The direction the motor turns is then determined by which of the two remaining wires are grounded.  If both wires are grounded or neither wire is grounded, the motor will not run.   I would think that the wires are wound side by side or the coils are wound side by side.   Magnetism is so sensitive to distance, if the coils were wound one over the other, there would probably a noticeable loss in performance from one coil.    

Nobody was "wrong" I don't think; just minor some technical difficulties.  

  No balance might be correct. If I recall right, adding wraps can be both underdone and overdone. So even if the the dual field is rewired in series it wouldn't improve anything (in my experince too) and could possibly be throwing off pulling ability of the armature sections enough to wipe out the motion...?

The dual field is not a favorite of mine either. They are the only Pulmor failures I've ever had; all field issues.

...ahh nope, not ALL. I lost a brush cap to an armature & heat.

Hmmm.  As the OP, I was indeed referring to its construction - not how it was operated.  That said....on my #50 the windings were indeed applied separately/sequentially during manufacture.  One complete winding is next to the center of the bobbin (the "inner winding") and the second complete winding was made on top of the first winding about 1 cm farther away from the center (the "outer winding").  Winding both simultaneously (i.e., so that each individual turn was laterally next to its twin) would have made more sense (or, to CW's comment, using a bonded double-strand of magnet wire) but that's not how it was done, at least in this case.

I had also thought a bit about David's mention that perhaps the difference in physical location could affect the magnetic properties and thus the performance when the car goes in one direction vis a vis the other- but have never noticed same.

Hmmm.  As the OP, I was indeed referring to its construction - not how it was operated.  That said....on my #50 the windings were indeed applied separately/sequentially during manufacture.  One complete winding is next to the center of the bobbin (the "inner winding") and the second complete winding was made on top of the first winding about 1 cm farther away from the center (the "outer winding").  Winding both simultaneously (i.e., so that each individual turn was laterally next to its twin) would have made more sense (or, to CW's comment, using a bonded double-strand of magnet wire) but that's not how it was done, at least in this case.


Over the past 50 years, I have serviced a large number of 50 gang cars (all variations), #69 maintenance cars, and many other Lionel double wound motors.  I cannot recall seeing one wound as you describe. Maybe yours had been rewound before you got it.

C W Burfle posted:

Over the past 50 years, I have serviced a large number of 50 gang cars (all variations), #69 maintenance cars, and many other Lionel double wound motors.  I cannot recall seeing one wound as you describe. Maybe yours had been rewound before you got it.

Double hmmm - it sure seemed like original factory work (at least until I got hold of it to rewind it manually)   One never knows, though - if mine was just an anomaly, that would help explain things.

Does your Gang car  brush plate have it's horn centered or off to the side?
How are the bends made to the ends of the reversing slide:
one simple 90 degree bend down or is the end bent down and then back up where the bumper mounts?

Just curious.

C W Burfle posted:

Does your Gang car  brush plate have it's horn centered or off to the side?
How are the bends made to the ends of the reversing slide:
one simple 90 degree bend down or is the end bent down and then back up where the bumper mounts?

Just curious.

Sorry for the delay in getting back.  The one I'm referring to has the centered horn and the "down and back up" bend at the ends of the reversing actuator plate.  Which, subsequent to my prior post, my 4YO proceeded to drop and shatter the brush-holding housing into little pieces.  Back to the workshop...