3-pole motor with DCC?

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jwb

Member
I have an Athearn 0-4-2T from about 1960 (got it secondhand in the 1970s). I've pulled it out now and then and have improved the pickup. Now I think it would be fairly easy to isolate the motor from the frame, and there's plenty of room inside the shell for a decoder. However, I'm not sure what DCC would do to the 3-pole motor. Does anyone have insight or experience?
 

Burlington Bob

Well-Known Member
To the best of my knowledge, DCC doesn't care if it's a three pole motor or a five pole, straight or skew wound. A five pole skew wound motor will run smoother than a three pole straight wound motor. Kind of the difference between a Cadillac and a Yugo. The biggest concern is making sure that the motor is insulated from the frame.
 

bnsf971

Gomez Addams
Staff member
Several modern, DCC ready locomotives come with three pole motors. Depending on the condition of the running gear and motor, it should do okay.

BTW, I don't think I've seen an Athearn 0-4-2, can you post a photo of it?
 

jwb

Member
I haven't photographed mine, and it's disassembled for DCC install, etc right now -- will post when farther along. But here's a prototype photo:

 

Iron Horseman

Well-Known Member
I'm not sure what DCC would do to the 3-pole motor. Does anyone have insight or experience?
The motor power that comes out of a DCC decoder is DC. It should work just fine. The only issue I can think of might be the current draw. Some of those AHM motors could pull 1 amp. continuous.
 

wombat457

Well-Known Member
Staff member
A question if I may, and perhaps one that should have its own thread but, what is the difference between all of these "Motor Types" and which is the best to have if possible?

As said, maybe this should be or worthy of it's own thread and sorry for side tracking jwb.
 

wombat457

Well-Known Member
Staff member
Bob,

Thank you. The wikipedia one just confused the hell out of me, while the other I found to be excellent and understandable, even to me. Now I know, or have a better idea of, what to look for in a locomotive other than just "good looks". I assume that this applies to all scales as well, meaning these 5 pole motors.

What I also found interesting, and that should have been obvious to me, was that to get the optimum performance you need to have "complimentary" equipment, that simply having one of the 5 pole motors wont give penultimate performance alone.
 
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wombat457

Well-Known Member
Staff member
So I am looking for a 5 Pole Skewed Motor when buying a locomotive. You do realise that all of this new info to me is taking all the fun out of buying loco's now ... :)
 

Iron Horseman

Well-Known Member
Thank you. The wikipedia one just confused the hell out of me, while the other I found to be excellent and understandable, even to me. Now I know, or have a better idea of, what to look for in a locomotive other than just "good looks". I assume that this applies to all scales as well, meaning these 5 pole motors.

What I also found interesting, and that should have been obvious to me, was that to get the optimum performance you need to have "complimentary" equipment, that simply having one of the 5 pole motors wont give penultimate performance alone.
DC motors by definition are inefficient and poor performers because of the split ring contacts required to continually reverse the polarity.

Well I'm glad I didn't post my explanation! But to further answer your question really good motors have 9 to 13 poles, but the extra performance is not worth the additional cost for model railroaders. However, there was a fellow selling some used 9 pole Swiss ball bearing motors on e-bay a while back for under $60! They were the wrong size for any of the re-motoring projects I have on the bench so I forced myself to pass.

Going deeper into motors one gets into the whole "can" vs "coreless" motor controversy. It is another study in how the definition of things gets distorted and changes over time. Then finally there are brushless DC motors - which I have no idea how work.
 
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wombat457

Well-Known Member
Staff member
Okay, "brain over load" happening. Why is it that every time I ask a question, the answers never seem to be as straight forward as the question? :) Ahhh ... solution, stop asking questions that result in answers that only add to the confusion! Damn I'm smart :rolleyes:

By the way guys, that wasn't meant as a shot at you - but a dig at me :)

Your answers are great and just go to show how little I know about this side of Model Railways .
 

gregc

Apprentice Modeler
What I also found interesting, and that should have been obvious to me, was that to get the optimum performance you need to have "complimentary" equipment, that simply having one of the 5 pole motors wont give penultimate performance alone.
is penultimate performance really necessary? I've been told that the motto at GE is "Good Enough". The customer does not pay more for exceeding needs or expectations.

I'm happy for those that can buy 21st century models of locomotives for their favorite railroads. I'm lucky to find accurate camelback locomotives for my railroad (Reading) that were manufactured a 1/2 century ago (1960s) and pleased that DCC provides better than expected performance using such ancient motor technology.

I believe the motor shown below is from slot cars
DSC03878.jpg
 

wombat457

Well-Known Member
Staff member
is penultimate performance really necessary? I've been told that the motto at GE is "Good Enough". The customer does not pay more for exceeding needs or expectations.
Unfortunately, it is that very way of thinking that has resulted in increased costs and reduced quality of products. While the customer may not pay for doing something better than expected, the customer does expect value for money. If that is what GE goes by then all their saying is that they can do it, but wont and that giving the customer the bare minimum is okay. Problem with that mentality is that as the company relies on customer apathy, they will continually drop the standards and the quality while increasing the pricing and still be able to apply the same BS principle.

Anyway, aside from that about GE and similar companies, I believe it is all about personal expectations. If you don't expect a great deal then something that is not all singing and dancing is fine - if it meets your requirements. While I think accepting "good enough" is a little silly, I don't have a problem with it at all.

My way of thinking is different though. If there is something out there that is going to perform better than something else, why not get it? Why not exceed our requirements to have something that maybe better and that may increase our enjoyment of our hobby?

Let me put it to you this way ... and I'll use Athearn as the example. They have 3 different "levels" of locomotives, base, intermediate and top of their range. All of my Athearns are their Genesis Engines - the best that they make. I don't buy them because they are the best of what they have or to gloat or anything like that, I buy them because what they can do exceeds what I can do now; however, I know that I have an engine that I can grow into as I learn more and not have to replace them to catch up with my experience and knowledge.

While I do agree that things made 50 years are far far better quality than anything made now a days, most of those things cannot compete with what is available now a days in terms of what those things can do.

In short, I don't and wont settle for second best as I see it - it really is that simple. That isn't to say that I have anything against anyone who doesn't share that thought process, as I don't. It is very much each to their own and what each of us finds acceptable based on our own expectations.
 

gregc

Apprentice Modeler
thanks for the thoughtful response

If that is what GE goes by then all their saying is that they can do it, but wont and that giving the customer the bare minimum is okay. Problem with that mentality is that as the company relies on customer apathy, they will continually drop the standards and the quality while increasing the pricing and still be able to apply the same BS principle.
bear in mind that Thomas Edison founded GE in 1892 and this mentality makes it successful building things from toasters, diesel locomotives and nuclear power plants on the Arabian peninsula.

My way of thinking is different though. If there is something out there that is going to perform better than something else, why not get it? Why not exceed our requirements to have something that maybe better and that may increase our enjoyment of our hobby?
as you said, everyone's expectations and economic situation is different. This is why I, and I believe most of us, can't even afford second best and drive a Chrysler, not a Mercedes, much less a high-end Mercedes.


engineering is often about using inexpensive components and technologies (electronic and firmware) to achieve the performance of more expensive components alone.

Linn Westcott circuits leading up to his True Action Throttle (TAT) attempted to achieve/exceed the performance of more expensive motors using inexpensive motors. (I don't believe motors were better back then). I believe most DCC decoders do this today using PWM. Would there be a noticeable difference in performance using a more expensive motor with a typical DCC decoder?

as the name implies, his TAT also attempts to mimic the behavior of the train by providing momentum and requiring braking. I believe most decoders have momentum (not sure about braking).

his TAT also included a compensation circuit that could adjust the speed of the motor based on the current load. This circuit could actually increase the speed of a train going up a hill and slow it down when going down hill. Of course it was usually adjusted to do the opposite as real trains do.

how many modelers would value (pay more for) a feature (change speed on hills) in decoders using firmware monitoring BEMF rather than buy a better more for (?) better performance?
 
...Why is it that every time I ask a question, the answers never seem to be as straight forward as the question? :)...
Something that I have learned that seems to apply to almost every field of knowledge is the more you learn, the more you realize what you don't know.
 




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