3-pole motor with DCC?

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Espeefan

Well-Known Member
I believe the motor shown below is from slot carsView attachment 47626
Nope. Too tall! Looks to be a vertical worm drive of 1950's vintage. Varney had similar models. Slot car motors are wound for higher speeds as well.

The interesting discussion on motors aside, I have noticed that some older units do not take DCC well. Be careful. I once smoked an older Tyco motor just by installing a decoder in the locomotive. It ran for a few seconds and the factory installed smoke escaped. Once the smoke gets out they don't work at all!
 

wombat457

Well-Known Member
Staff member
thanks for the thoughtful response



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.



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?
You mention a few things that do exist by using DCC, the change of speed control for example. All of that is great but what is the point of it if the motor (the thing that this thread is about) is incapable of making those great features happen?

The entire point of my post, that elicited (apparently) your initial reply was in reference to the Motors in a Loco and the fairly large difference between what 3 pole motor can do compared to 5 pole skewed motor. That was the extent of the post when I referenced having the penultimate thing.

Bottom line is a simple one, putting economics aside, if you had the opportunity of buying a motor that did X amount OR a motor that would do X Y Z, which would you buy? Which would you prefer?

I do fail to see the point in having all this wonderful feature packed DCC stuff, which we all seem to take for granted, if the motor in the engines aren't capable, because of what they are, of getting the engine to utilize all of those features. That to me seems to be waste of money, regardless of how much you may or may not have.

The perfect example is having a 3 pole engine that, by the very nature of its design, is (evidently) incapable of a smooth and realistic start or stop. Where as a 5 pole motor is capable of that and a 5 pole skewed motor more so - so why not have the 5 pole skewed motor instead? In the terms and context of the thread - having a 5 pole skewed motor would be the penultimate of motors I would think.

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.
Absolutely, and it gets so frustrating,.
By CSX Robert;



Ain't it the truth!
Mmm ditto to that sir.
 

Mark R.

Custom Painter
Most engines today do use a five pole skewed armature - even the RTR Athearns.

A non-skewed armature requires more voltage to overcome the cogging action between the winding plates. The magnets hold the segment in position, so there has to be sufficient voltage in the winding to overcome the magnetic pull. The more segments there are, the easier it is to overcome the magnetic field and rotate to the next segment. A three pole motor requires considerable more voltage to overcome this because of the greater distance between the segments.

Some decoders have specific settings (TCS) for older three pole motors that will give high voltage spikes to help nudge the segments to move without applying excess constant voltage. This allows older three pole motors to actually perform better at lower speeds. It's not at all true that a decoder can't make a poor motor perform better.

Mark.
 

gregc

Apprentice Modeler
Bottom line is a simple one, putting economics aside, if you had the opportunity of buying a motor that did X amount OR a motor that would do X Y Z, which would you buy? Which would you prefer?
it's hard for me to put economics aside and while I might prefer, I would rather not buy, pay extra $$ for performance or capabilities I don't need.

The perfect example is having a 3 pole engine that, by the very nature of its design, is (evidently) incapable of a smooth and realistic start or stop.
I disagree with the above statement. But I generally agree with your point, which I think is that buying ($$) the best you can should guarantee best performance.

i'm suggesting that smooth performance is achievable with an older motor and a suitable DCC decoder. This is my experience with the 3-pole motor in the picture I posted using a TCS decoder. If that's not the case, buying a better ($) motor may be necessary, but buying the best ($$$) is not.

engineering is not about designing/building the best, but designing/building what is "good enough" to meet expectations. I'm an engineer.
 
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Iron Horseman

Well-Known Member
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.
Absolutely, and it gets so frustrating.
No, no, that is what makes life interesting and exciting. If I don't learn a couple new things every day, it is a wasted day.

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.
No, Thomas Edison founded Edison General Electric many years before that. He was thrown out of his own company by JP Morgan for clinging to his original DC power system, and loosing the Niagra Falls Power station project. Morgan who (after essentially stealing the Tesla AC patents to use) merged it (EGE) and Thompson-Houston Electric into the current company we know as GE.
 
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wombat457

Well-Known Member
Staff member
Greg,

I agree with you on one point, don't pay for something you don't need ... the "each to their own thing".

"...engineering is not about designing/building the best, but designing/building what is "good enough" to meet expectations..."

Apparently not, close enough is good enough does not meet my expectations by a long shot, but does explain the low standards set IF that is what engineering companies in the US base their engineering development on.

Considering I have never been approached, surveyed etc about my expectations - I can only surmise that it is the companies and engineers who decide what the public's expectations are. IF that really is the basis of how engineers build things, then it is they who dictate the standards and has nothing to with what the public expects. To that end, those standards are then dictated by the cost, and we all know that the majority of companies place more emphasis on THEIR costs and BOTTOM LINES than they do anything else. Make CHEAP, CHARGE excessive ... and then tell everyone that is good enough UNTIL it fails.

IF that is really how engineering companies "fortune tell" their development then tell me this how do they (or anyone for that matter) know what the Public Expectation is? Seems to me that that is nothing more than a throw away line in an attempt to NOT do something.

Anyway,as I said, each to their own but I don't settle for second best when it comes to my layout - and Model Trains is what was being spoken about, not cars etc.
 

wombat457

Well-Known Member
Staff member
Horseman,

That is interesting about Edison and GE - just a little curious to know how on earth some one can get thrown out of their own company though. Was there more to that than just Edison's determination to stick with his DC power system do you know?
 

Burlington Bob

Well-Known Member
People start, control, lose control, then get "kicked" out of "their" companies all the time. A mixture of intrigue, subterfuge, egos, power struggles and finances.
 

Burlington Bob

Well-Known Member
Just because a motor is only a three pole with straight windings doesn't rule out the capability of smooth starts and stops, especially when using DCC. There are many variables that affect the smoothness of operation of our trains. Weight, friction and gear ratio are the main factors that we deal with. All things being equal, a skew wound five pole motor will out perform a straight wound three pole motor because everything is equal except the design of the motors.

We can change the performance by lessening the amount of friction or changing the gear ratio or by doing both both.. If we use a straight wound three pole motor in a low friction design with a gear ratio that requires a higher motor rpm to achieve a certain speed this loco will outperform one with a higher friction drive and a gear ratio that goes the same speed as our three pole unit at a lower motor rpm even though it is powered by a skew wound five pole motor.

Now we add a DCC decoder to the mix. There are decoders that have very good speed control and ones that don't have good control. Again, depending on the combination that we have, you may end up with smoother operation from the three pole motor than the five pole.

The moral of the story? You can't judge a loco only by its motor.
 

gregc

Apprentice Modeler
Considering I have never been approached, surveyed etc about my expectations - I can only surmise that it is the companies and engineers who decide what the public's expectations are.
consumers, such as yourself, are surveyed by what they purchase (we vote with our dollars).

Corporate marketing departments determine what product cost target and requirements are. Engineers are expected to meet both conflicting goals.

Unpopular products that don't meet consumer expectations because of price or quality are discontinued. And competition attempts to improve the performance or make less expensive alternatives to successful products.

... not everyone can afford a Benz.

thanks for the info on G.E.
 

wombat457

Well-Known Member
Staff member
Just because a motor is only a three pole with straight windings doesn't rule out the capability of smooth starts and stops, especially when using DCC. There are many variables that affect the smoothness of operation of our trains. Weight, friction and gear ratio are the main factors that we deal with. All things being equal, a skew wound five pole motor will out perform a straight wound three pole motor because everything is equal except the design of the motors.

We can change the performance by lessening the amount of friction or changing the gear ratio or by doing both both.. If we use a straight wound three pole motor in a low friction design with a gear ratio that requires a higher motor rpm to achieve a certain speed this loco will outperform one with a higher friction drive and a gear ratio that goes the same speed as our three pole unit at a lower motor rpm even though it is powered by a skew wound five pole motor.

Now we add a DCC decoder to the mix. There are decoders that have very good speed control and ones that don't have good control. Again, depending on the combination that we have, you may end up with smoother operation from the three pole motor than the five pole.

The moral of the story? You can't judge a loco only by its motor.
The last sentance in your post says it all then. I was of the impression, due to what I read about poles and skewered motors etc, that a 5 Pole Skewed Motor was going to offer better performance than a 3 Pole motor by virtue of its design. I also read what you were saying about things needing to be compatible with each other too which make your last sentance so much more pertinent.

Thanks mate.
 

Iron Horseman

Well-Known Member
That is interesting about Edison and GE - just a little curious to know how on earth some one can get thrown out of their own company though. Was there more to that than just Edison's determination to stick with his DC power system do you know?
Tons more. Books have been written on the subject. There was actually a pretty good mini-series on it on one of the cable networks last year called something like the men who built the 20th century.

JP Morgan had been funding Edison Electric for years. JP Morgan's house was the first one to be lighted with electricity. JP's wife complained about the noise of the generator running in the cellar. This highlighting one of the big problems with the DC system was the close proximity that the generation had to be to the consumption. JP's father told him not to put his money in Edison, but he did anyway. When the Niagra Falls project and World's Colombian Exposition both went south JP had mud on his face in the finance world esp. from his father. Fed up with Edison he decided to go it on his own with the proven Tesla technology.

Then there was the whole deal about the bad press that Edison got with his most stupid invention ever - the electric chair.

One of the bizarre side twist of this saga was that Tesla had dated JP Morgan's daughter for a while. Had they actually married, JP would have gotten access to all the patents without the shady dealings and subversion and Tesla would have been funded for life.

It is almost funny this came up, as the other day in the shower I realized that when Westinghouse handed over the patents to JP he should have also included Tesla's original royalty contract along with them. That would have also funded Tesla's wireless and work to perpetuity. Not to mention making Tesla the richest person in the world - ever. None of the power companies wanted to fund Tesla's work because they found out his ultimate plan was to provide free electricity to the world.
 
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wombat457

Well-Known Member
Staff member
Sounds like it would make a great documentary style movie - not the typical hollywood fantasy stuff. So now there are at least two people in US history who essentially got screwed, Tesla and Lincoln. I have absolutely no doubt that there are not many more either.

Thanks for the lesson Horseman, while others may not find it interesting, I certainly do - cheers.
 

Mark R.

Custom Painter
The last sentance in your post says it all then. I was of the impression, due to what I read about poles and skewered motors etc, that a 5 Pole Skewed Motor was going to offer better performance than a 3 Pole motor by virtue of its design. I also read what you were saying about things needing to be compatible with each other too which make your last sentance so much more pertinent.

Thanks mate.
Re-read his first paragraph. A five pole skew wound motor WILL perform considerably better on its own merit than a three pole straight wound motor PROVIDED both drives are identical.

Mark.
 

wombat457

Well-Known Member
Staff member
Okay, so see if I got it this time. If the drive on a 3 pole motor is the same as the drive on a 5 pole skewed motor, then the 5 pole skew motor will be considerably better. Is that what your saying, or am I still in a different country?
 

Mark R.

Custom Painter
Okay, so see if I got it this time. If the drive on a 3 pole motor is the same as the drive on a 5 pole skewed motor, then the 5 pole skew motor will be considerably better. Is that what your saying, or am I still in a different country?
Yep, you got it now. :D

And for the record you ARE in a different country from ME ! ;)

Mark.
 
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wombat457

Well-Known Member
Staff member
YEAH! - does that make me knowledgeable about this stuff now then or what? :)

Yep, bad choice of words on my part, should have said planet :(

Okay, so is there is there any norm if you like. Do manufacturers now use mainly 5 pole or 5 pole skewed motors, or is there still a mish match of all three variations being made and sold depending on the makers model level?

In other words, if I were to buy a Genesis - am I going to get a 5 pole skewed motor due to that being Athearns top of the line engine? Where as if I buy there "bottom end engine" I might be more inclined to get a 3 pole motor. Basically, is there any sort of system used used by makers of engines to determine what motor they put in what engine?
 

Mark R.

Custom Painter
Pretty much most all manufacturers across the board use five pole motors today. I can't think of any current production models that would have a three pole motor in them. Three pole motors were found in early engines up until probably the late 80's. Anything of decent quality from the last twenty years will have a five pole motor

When Athearn converted from three pole to five pole, it was during the gold case era and they visually looked no different. You had to carefully look in the end of the motor and count the segments to see which one you were getting.

Now - always a wrench to add to the confusion - not all five pole motors are created equal. There are more than one supplier of motors to the manufacturers. Kato (and the older Atlas/Kato) motors were and still are probably the best out there. The Athearn Genesis are better than the Athearn RTR. The RTR is still the basic gold motor that has been around for ages and is still a crap shoot whether it will perform quietly or sound like a coffee grinder, due to poor tolerances. Bowser is moving to a new supplier for their motors as the most recent ones have been deemed rather week in the torque department. The new ones will walk away two Genesis engines in a tug-o-war !

Over-all, there really are no "bad" motors today, just some that aren't as good as others. Compared to the old three pole "slot car motors" we had growing up in the 60's and 70's, anything out there today is more than worthy.

Mark.
 




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