Author Topic: 3 poles for all!  (Read 10852 times)

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Mark5

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3 poles for all!
« on: December 22, 2010, 10:27:23 AM »
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Unfortunately, this has become a diversion from the core topic in the Bachmann GP7 thread, so I'm starting a separate thread for people to call me a looney. ;D

At what price would you stay then............? Bachmann's MSRP vs Kato's MAP price.....? We are talking apples to oranges.......

I'm not commenting on MSRPs, I'm commenting on 3 pole motors, which you assert are great. Yes, I'd leave if Atlas and Kato stopped using 5 pole motors on the majority of its locos.

and as you said; the Bachmann motor runs well enough.

No, I said the motor isn't bad enough for me to want me to re-motor. The Bachmann J's I have have excellent tooling shell wise so I have to weigh the total picture, Though the motor is poor it isn't bad enough for me to want to re-motor or get rid of my J's. Can you understand what I'm saying here?

I could easily demonstrate (in DC) on a level test track the slow speed non-smoothness of the bachmann (and Kato) 3 polers in controlled experiments. Fortunately the difference compared to a decent 5 pole motor is subtle these days, but significant enough to annoy me.

This is likely one of those things were each of focus on different aspects of the hobby. Realistic acceleration and deceleration are high up on my list of priorities.

Today's 3 pole motors are miles from the 3 pole motors of the 1970s (when I started taking motors out of locos and "playing" with them).

But please don't marginalize criticism of 3 pole motors. They are inherently inferior to 5 pole motors - otherwise I suppose we would start seeing them appear in upscale HO locos right?

3-pole or 5-pole.  Those Bachmann GP7's ran well for me.   Nice slow speed operation.  

Yeah, maybe the decoder is creating much of that, but still, if it runs well, it runs well.  


I've never seen them (the Bachmann 3-polers) run in DCC. Maybe DCC works miracles here. Will probably get to witness them in DCC sometime next year.

I want to go to DCC in the future (and I will) primarily for light control, but at the moment that would mean big bucks for me (a large fleet of locos). It would be really cool if DCC "cures" the low speed performance of modern 3 pole motors.

Mark
« Last Edit: December 22, 2010, 10:37:48 AM by NandW »

sizemore

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Re: 3 poles for all!
« Reply #1 on: December 22, 2010, 10:35:15 AM »
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I want to go to DCC in the future (and I will), but at the moment that would mean big bucks for me (a large fleet of locos). It would be really cool if DCC "cures" the low speed performance of modern 3 pole motors.

Mark

Yes there is a "remediation" for the 3 pole cogging at low speed. In DCC you have BEMF, or "Speed Stabilization", I can have my little 44T crawl ties (with a DZ143MO (IIRC)).

http://www.tonystrains.com/technews/introto_bemf_pid.htm

It's not bulletproof but it gets the job done.

The S.

Mark5

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Re: 3 poles for all!
« Reply #2 on: December 22, 2010, 10:37:04 AM »
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Thank you S. - I look forward to witnessing this. ;D

Mark

up1950s

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Re: 3 poles for all!
« Reply #3 on: December 22, 2010, 11:06:34 AM »
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Quote
I want to go to DCC in the future (and I will), but at the moment that would mean big bucks for me (a large fleet of locos). It would be really cool if DCC "cures" the low speed performance of modern 3 pole motors.

But then how much better does DCC improve 5p motors ? The quest for info will never end on this , as will the lack of an in depth scientific truth table rating the performance & wear capabilities of the individual components of all types of N Scale capable motors . Who would fund such a thing ? Germany might have the enthusiasm , camera manufactures would care if they used motors of that size , and NASA would find out if they needed such motors . We have many manufactures in N that are doing a balancing act with GOOD ENOUGH vs COST equations . Maybe some manufactures who farm out to Asia to produce their designed locos are locked into the motors that the foreign builders have on hand , or have available via a sub contractor . That would account for the false advertising we see time to time . Initial request to have a loco produced by a time frame to soon to have all the components on hand , so in order to keep the time contract , the motor isn't what was ordered . Maybe it's just a change in plans that the advertising department wasn't advised about . No matter what the reason , it isn't proper for the buyer .


Puddington

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Re: 3 poles for all!
« Reply #4 on: December 22, 2010, 11:09:04 AM »
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I too run in DC and I can clearly tell the diffference between the smooth starts and stops of a flywheel equipped five pole motor and a non flywheel three pole. I am not saying there is no difference.... I am saying that the newer 3 pole motors are not the "junk" that many over the past three years have made them out to be. (Your observation about the early motors of the 1970's being 100% accurate)

My Bachmann 16-44's are great locomotives; they run like a dream; better than a bunch of my Atlas loco's (and thus a tribute to the differeing QC that almost all mfg's have on differeing days one assumes) They are not "junk"...but some (and I am not saying you Mark) dismiss all products that haven't got a five pole, flywheel under the hood as garbage... often without having seen or run them product.... and that's what drives me nuts......

The new Bachmann Geep is a "train set" locomotive as someone put it. My contention is that if the quality of the Bachmann three pole motor is now considered a train set standard, then the "standard" has gone way, way up in a few years because their three pole motors provide good, reliable performance..... not great performance........but solid performance and they certainly win the award for value.
Model railroading isn't saving my life, but it's providing me moments of joy not normally associated with my current situation..... Train are good!

Ian MacMillan

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Re: 3 poles for all!
« Reply #5 on: December 22, 2010, 01:39:45 PM »
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Yes there is a "remediation" for the 3 pole cogging at low speed. In DCC you have BEMF, or "Speed Stabilization", I can have my little 44T crawl ties (with a DZ143MO (IIRC)).

http://www.tonystrains.com/technews/introto_bemf_pid.htm

It's not bulletproof but it gets the job done.

The S.

I was gonna mention that as well, but I was driving! BEMF is very nice and in some situations acts like a "virtual flywheel" for motors sans flywheels.
I WANNA SEE THE BOAT MOVIE!

up1950s

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Re: 3 poles for all!
« Reply #6 on: December 22, 2010, 04:26:53 PM »
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I was gonna mention that as well, but I was driving! BEMF is very nice and in some situations acts like a "virtual flywheel" for motors sans flywheels.

Anti dynamic braking . ...... Dynamic Momentum ?

sizemore

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Re: 3 poles for all!
« Reply #7 on: December 22, 2010, 04:38:17 PM »
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Anti dynamic braking . ...... Dynamic Momentum ?

Think of it like inserting an AC pulse on a DC throttle. Except for its not AC, its modulation/amplitude within the DC current itself. It add's torque, and smooths the current allowing better motor operation.

The S.

93cram

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Re: 3 poles for all!
« Reply #8 on: December 22, 2010, 05:06:21 PM »
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It would be really cool if DCC "cures" the low speed performance of modern 3 pole motors.

Mark, yes it does  8)
I begun with DCC for sounds effects and has stayed with it for low speed control.
May be some high end DC controller could do the same, but I've never own one, so basically, DCC changed my view
on model trains operation, particularly in N scale.
First time I ran a decoder equiped engine (a Bachman 2-8-0 with a TCS decoder), I couln't believe my eyes : the engines crept so slowly in
speed step 1 that you had to look hard to tell if it was moving or not  :o 8)

Marc

victor miranda

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Re: 3 poles for all!
« Reply #9 on: December 22, 2010, 05:59:18 PM »
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welcome to the future.

the 3 pole vs 5 pole fight fails to have any meaning when
the cost of the magic throttle that hides ALL the flaws
of a 3 pole motor falls below the cost difference between the
two motors.

In this corner we have an ordinary atlas gp unit and still champ!.
In this corner we have the b-mann magic throttle installed gp unit.

gentlemen shake hands and come out fighting.

I tell ya folks this is shaping up to be a great fight!
in terms of price, right now the atlas is ahead.
in terms of performance, the atlas is also ahead.

by golly folks it sure is close!

among the things we don't know how they will play out in this
battle of the titans;

is if the b-mann will drop in price or improve the magic throttle
to make this a clear win.
leaving the question can Atlss win this bout with motors that last longer
than 60 hours or pickups that wear won't through.

and finally who knows! maybe this battle royale will be decided
over some other factor like ability to pull n-scale cars!!!!

tune in next year!
the crystal ball may be less cloudy then.

daniel_leavitt2000

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Re: 3 poles for all!
« Reply #10 on: December 22, 2010, 06:35:53 PM »
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If we are going to do a multitude of tests on an engine with a 3 pole vs an engine with a 5 pole might I suggest using the Athearn SD7x which came in both versions. Even this isn't a perfect comparison as the 3 pole is an old 1970's variety.

My CN (equiped with a 5 pole) is both smoother, quieter and slower than the SP version.
You've crossed the walls, excelled
Further along through their hell
All for my heart, I watch you kill
You always have, you always will
Now spread your wings and sail out to me

victor miranda

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Re: 3 poles for all!
« Reply #11 on: December 27, 2010, 02:50:53 PM »
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after re-reading this and having another reason
I found myself in my basement watching a b-mann 44 tonner.

at slow speeds, it cogs.

so far I do not see that bachmann has cleared the
'as good as' level even with the DCC decoder.

it cogs using DCC.
it cogs using DC.

v

Ian MacMillan

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Re: 3 poles for all!
« Reply #12 on: December 27, 2010, 02:56:03 PM »
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DCC in general is not going to solve problems. I it will help with slow speed operations... but to fix "pole issues" like we are talking you need BEMF. 

Add a BEMF decoder in a Bman 44T and you will see significant improvement.
I WANNA SEE THE BOAT MOVIE!

Mark5

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Re: 3 poles for all!
« Reply #13 on: December 27, 2010, 03:55:51 PM »
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after re-reading this and having another reason
I found myself in my basement watching a b-mann 44 tonner.

at slow speeds, it cogs.

so far I do not see that bachmann has cleared the
'as good as' level even with the DCC decoder.

it cogs using DCC.
it cogs using DC.

v

I witnessed this. It cogs less with DCC but still COGS.

I understand that the Bmann decoder is a decoder "lite" and I assume has no "BEMF".

Mark

sizemore

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Re: 3 poles for all!
« Reply #14 on: December 27, 2010, 04:03:08 PM »
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I witnessed this. It cogs less with DCC but still COGS.

I understand that the Bmann decoder is a decoder "lite" and I assume has no "BEMF".

Mark

If the 44T you saw had the OOTB installed decoder it will still cog. You are correct it's "lite", more function rather than finesse (such as BEMF or Speed Stabilization).

The S.