Athearn Challenger and Life-Like 0-8-0: Same motor

[VonRyan]

[Devil's Advocate]

so now I get to my point...

I tell three and five apart by how they start relative to how they stop.
5 usually starts close to the speed they stop
3 usually ramps up to a happy speed.

as you slow a 3 pole from the happy speed
it will often sustain a slower speed and then
in unreliable speed range the MOTOR will cog.

pulses and gears and flywheels will all add to the conga line.

Since my though processes tend to be very linear and logic-driven, I'll step in here and say that Peteski is indeed on to something here, although not exactly.

Victor, your statement of:

pulses and gears and flywheels will all add to the conga line.

does indeed seem to imply that a flywheel is a magnifying factor in the cogging of a three-pole motor.
However, your statement is more in line with saying that the entire drive-train of a model amplifies the cogging effect.
So in effect, Peteski is right in his interpretation.
Now that isn't to say that what was written was meant to be said, but rather as it was written perhaps the opposite of what was meant was instead what was said.

[/Devil's Advocate]

I'm no English Composition professor, and I know English isn't Peteski's first language ( ) but that isn't to say that this isn't a productive discussion that is taking place here.
After all, how else can we improve the running quality of our models except by questioning what we already know and in turn begin to hypothesize ways to make improvements.

[victor miranda]

well,
it would help in attempting to understand if you didn't add words.
cog and conga line are not the same thing.

well so much for the easy way.

At times, I am not sure you listen to you.

lets talk flywheels for a bit.
you said "Once the the is overcome, the motor will speed up."
I am assuming you meant "Once this is overcome, the motor will speed up."

yup I agree as far as that goes, what you didn't say was
which caused the jackrabbiting...
the 3 pole or the massive flywheel.

I tend to think the three pole....

the other thing about flywheels is that they change the frequency or harmonics
in the motor/gears/drivers/train.

If harmonics is just frequencies, changing one weight can be balanced out by a different weight.

so it is possible under some bizzare stack of circumstances that a bigger flywheel
might somehow add to a percieved cog...

however that ain't my claim, just pointing out a possibility.

ever see a caboose bobbing at the end of a train?
have you looked into why?

at some loco speeds, I have seen it bob with enthusiasm
and at other speeds, not really bobbing at all.

there are a lot of ways to see what cogging does.
in general, a biiiiig flywheel will hide cogging.
as you pointed out, that solution may come with other problems.

to repeat
cog does not equal conga line.

so the rest of the post with the
pulsating geared conga line
is good? no comments for the rest?

[victor miranda]

Hi VonRyan,

yeah, thank you for your untimely advocation.

I crack me up.

part of the motor discussion involved here is perception.
If you can't see the problem, there is no problem.

If you can see the problems... or not...
tell us your thinking.

one of the things that definitely colors my perception about the motor that started
this thread is that I found them is dead locos.
so there is a tendency to think... the motor itself is a sign of a problem.


what amuses me is the lack of complaining about the price of that loco
and the qualities of the motor installed.

is no one going to ask Mr. Magliaro why he is fixing the loco?

victor

[mmagliaro]

Fixing which loco?  The 0-8-0, or the Challenger?

In the case of the 0-8-0, its woes are long and overdocumented in a 40+ page Atlas Forum thread from long
ago.  But none of those problems, I concluded, were caused by the motor.  I was hackin' and fixin'
on that loco because of mechanism binds, poor pulling, and assorted other issues, and I came to the
conclusion that after I had ironed that all out as smoothly as I could, the 3 vs 5 pole motor did not
make any difference.

In the case of the Challenger, this engine's motor was contaminated by oil (the first-run malady that struck
a lot of them, so I am told).   So it keeps loading up the commutator slots with carbon and then shorting
itself out.   I did clean it once, but I suspect that the brushes absorbed enough oil that they are soft and keep
clogging up the arm, so I replaced the motor.

[victor miranda]

I remember the 0-8-0.
it was the challenger that had my curiosity.

interesting.  motor brushes can absorb oil you say.

that I will note...
I would think arching would burn it to carbon...
and water and co2 and no2....

it has been a while since I have had a clogger..
and that tid-bit o info may explain a lot

thanks

[peteski]

well,
it would help in attempting to understand if you didn't add words.
cog and conga line are not the same thing.

well so much for the easy way.

At times, I am not sure you listen to you.

lets talk flywheels for a bit.
you said "Once the the is overcome, the motor will speed up."
I am assuming you meant "Once this is overcome, the motor will speed up."

yup I agree as far as that goes, what you didn't say was
which caused the jackrabbiting...
the 3 pole or the massive flywheel.

I tend to think the three pole....

the other thing about flywheels is that they change the frequency or harmonics
in the motor/gears/drivers/train.

If harmonics is just frequencies, changing one weight can be balanced out by a different weight.

so it is possible under some bizzare stack of circumstances that a bigger flywheel
might somehow add to a percieved cog...

however that ain't my claim, just pointing out a possibility.

ever see a caboose bobbing at the end of a train?
have you looked into why?

at some loco speeds, I have seen it bob with enthusiasm
and at other speeds, not really bobbing at all.

there are a lot of ways to see what cogging does.
in general, a biiiiig flywheel will hide cogging.
as you pointed out, that solution may come with other problems.

to repeat
cog does not equal conga line.

so the rest of the post with the
pulsating geared conga line
is good? no comments for the rest?

Sorry Victor, that was a poorly written reply, but you understood be better than I often understand your posts.    I went back and edited it to make it clearer.

I guess I'm still confused by the conga line.  Is it good or bad, and what exactly does it mean (in more technical terms).  All I visualize is a swaying and gyrating Ricky Ricardo.  I guess your prolific use of metaphors doesn't halp me to understand your thoughts.

Cody: Thanks for looking at this with another pair of eyes. 

[victor miranda]

you may want to keep editing peteski

[peteski]

you may want to keep editing peteski

 

 

[mmagliaro]

I remember the 0-8-0.
it was the challenger that had my curiosity.

interesting.  motor brushes can absorb oil you say.

that I will note...
I would think arching would burn it to carbon...
and water and co2 and no2....

it has been a while since I have had a clogger..
and that tid-bit o info may explain a lot

thanks

To be fair, that is just a theory (that the brushes absorb oil and get soft).  I discussed this with our friend
Tony Hines and that is his theory, and he has seen a lot more failed first-run Challengers than I.
Generally, Athearn was fixing them by replacing the motor.  They did not attempt to clean them.

It does seem plausible.  Once this motor failed, cleaning seemed to save it, but it only lasted on the order of 10-15 hours
and then loaded up and shorted out again.   The replacement motor is making it run far better than it ever did.
And in fact, it draws considerably less current than the other motor (about 80 vs 125 mA at 7 volts pulling a train,
for example).

Perhaps it was the oil contamination.  Perhaps it was just a bum motor.  I will probably never know.
The important thing is that now it runs beautifully, which is all my customer will really care about.

[peteski]

I remember the 0-8-0.
it was the challenger that had my curiosity.

interesting.  motor brushes can absorb oil you say.

that I will note...
I would think arching would burn it to carbon...
and water and co2 and no2....

it has been a while since I have had a clogger..
and that tid-bit o info may explain a lot

thanks

Aren't brushes already made out of compacted powdered carbon and copper?  Sounds like more carbon from burning oil could be beneficial. 

I have also observed oily commutators on many model motors. Those motors run very poorly and the powdered (and conductive) brush material seems to collect in the gaps between the commutator segments further degrading the motor's performance.

But even motors with dry commutators they seem to run much better after an initial 30-second run. That initial run seems to "clean" the commutator or the brush ends (or both).   After that run the motor is be able to start running and maintain running at a voltage lower than that of the initial run (after sitting idle for a while).  This happens to all permanent motors with commutators.

[victor miranda]

forumers,

I can't say exactly what happens when oil get onto or into the brushes.
I have guesses
let me start with the brushes themselves...

I have read in our small motors the brushes are carbon and copper and sometimes silver powder
that is compressed.  I assume some heat is involved and I have not  read that is part of the process.
magic!

so like sintered bronze bearings, I can only think the oil could soak into the brush.
I doubt the oil would soften the brush.

my guess is that the oil does  get burnt... some anyway and the rest gets spread over the commutator.
the carbon and copper dust stick to the oil and become a conductive ... paste?

I have seen the paste before and the next time, I will try  cleaning the brush
with acetone.  If the brush does not dissolve,  I may try a soak.

I have the impression that the b-mann square frame motor brushes fit the brush barrel
of the (what are we calling the motor?)
athearn motor.

Peteski,
I read in one of my posts that MP did use this same motor in the Pacific
so MP may have used more than one supplier over a few runs.

this 'athern' motor is not marked with a manufacturer name.

Max,
I recall you had a coreless motor from some one (nigel lawson?)
that lasted about 8 hours in one of your projects.

motors are important and can be such a pain.

victor

[peteski]

my guess is that the oil does  get burnt... some anyway and the rest gets spread over the commutator.
the carbon and copper dust stick to the oil and become a conductive ... paste?

I have seen the paste before and the next time, I will try  cleaning the brush
with acetone.  If the brush does not dissolve,  I may try a soak.

If you want to clean the commutator, I would recommend using naphtha - it is a solvent milder than acetone.

Whenever I need an oily (open-frame) motor cleaned I dunk it in my ultrasonic cleaner filled with naphtha.  It is an excellent degreaser.  While running the cleaner I can see cloud of brush material particles (which were trapped on the oily commutator) coming out like a dark cloud from the commutator area. This removes all the oily residues from the entire motor.  The brushes. the brush barrels and the commutator are oil-free.

I have the impression that the b-mann square frame motor brushes fit the brush barrel
of the (what are we calling the motor?)
athearn motor.

I suspect that small motor manufacturers do not produce their own brushes - they buy them from some company which manufactures motor brushes. That company probably has a catalog of brushes (from large to very tiny) and the motor manufacturer simply ises one of the regularly stocked brushes.  That is why it seems that different brands of motors use similar brushes - they might be identical.  Aren't Kato motor brushes also similar to ones you mentioned used by Bachmann?  How about the ones used in the old Rivarossi motors?

Peteski,
I read in one of my posts that MP did use this same motor in the Pacific
so MP may have used more than one supplier over a few runs.

this 'athern' motor is not marked with a manufacturer name.

I see. I think that I was looking at my 4-6-0 MP loco while the other motor mentioned here (non-MASHIMA) was in their 2-8-2 loco.

[mmagliaro]

....
snip
...

Max,
I recall you had a coreless motor from some one (nigel lawson?)
that lasted about 8 hours in one of your projects.

motors are important and can be such a pain.

victor

Yes, that is true.   All the "cheap" coreless motors like that one, pager motors, and others, have thin fragile
brushes that burn up in no time.  The Faulhabers and Maxons, while they do have finger brushes (not big
spring-loaded carbon blocks), do not seem to suffer the same fate.   I suspect that either the brushes themselves
are made of a more robust alloy, or the motor itself simply doesn't generate as much heat. 
I don't have any better explanation than that.

What it simply means is that all coreless motors are not the same when it comes to longevity.