DC loco idle on DCC, how long until the motor burns out?

[Gandy Dancer]

I run DC With a narrow pulse inserted on it to provide constant lighting....

 Makes me wonder what that is doing to my motors..... 

In that scenario (assuming a high frequency pulse rate), one is supposed to have choke coils installed on the motors to keep the pulses out, and capacitors on the light bulbs to keep the track power out of them.  There was a great article on this in MR back in the mid-1970s when this was a common way to get constant lighting.   Unfortunately I cannot recall the exact issue.  PFM sound systems used a similar arrangement to keep the sound out of the motors and the power out of the sound.

Edit - OK it was the early 1970s - December 1971.

[Villy]

I run DC

With a narrow pulse inserted on it to provide constant lighting....

 Makes me wonder what that is doing to my motors..... 

Of course my pulse is unipolar - that might make a difference...

 

Villy 

 

[jeffrey-wimberly]

I used to have that hanging on the wall in my office when I was a computer tech/programmer.

[R. T. POTEET]

Jeffrey-Wimberly of Leesville, Louisiana, you need to give some consideration to taking up model railroading as a hobby; it is very rewarding although those in it too long tend to go just a little wacky!

R. T. POTEET from the far, far reaches of the wild, wild west, I think I'm already beyond that point. I'm having a really good time with it.

What's that old jibe about, "You don't have to be crazy to work here but it sure helps!!!"

[jeffrey-wimberly]

I thought just as long as they weren't of the open frame or pancake type, I thought they could last forever. :confused:

Apparently not. Two tests on the same type motor, two burnouts.

[DigitalGriffin]

I tried this back in June of this year with an old analog Athearn loco. The motor lasted 2 1/2 hours before the brushes burned out.

I thought just as long as they weren't of the open frame or pancake type, I thought they could last forever. :confused:

[PA&ERR]

Jeffery,

You are model railroading's answer to The Mythbusters!

George

[jeffrey-wimberly]

Well, that wasn't my intention.

[Gandy Dancer]

I was saying that being exposed to a temp of 400+F will kill a field magnet.

That might have been what you were trying to say, but that is not what you said.  What you said indicated it was the ONLY way.

You would have to get the magnets to heat up to 400+ degrees F to effect them

emphasis & color added by me.

[dinwitty]

that a curious deal about running DCC on a DC motor, it is AC, and getting the motor to turn takes a magnetic field. With a serious tape de-gausser, which can erase reel-to reel tapes or casettes, it could de-magnetic an HO motor. Which makes me wonder about applying DCC (AC) power to a DC motor. It may not kill the motor right off, but with enough time might kill the magnet. But you can re-magnetize them if you know how. DC on DCC is more like to me ...yeh you can do it, but is it right?

 I believe the can motors can live with it more that the older motors.

 

[jeffrey-wimberly]

I was saying that being exposed to a temp of 400+F will kill a field magnet. I'm sure there are other ways to do it. I've worked around electricity all my life, even completely rewired my trailer to HUD specs so it would pass code inspection. I've rebuilt many radios and TV's in my time and have been building computers as a hobby for twenty years, so I'm not a dunce when it comes to the properties of field magnets and electro-magnets, both of which are present in the DC motors used in our model trains. Now I know that extreme high temperatures can depolarize a magnet. So can subjecting it to an intense electro-magnetic field.

[Isambard]

Great experiment and thanks for doing it.  So now we can say that the Myth that running DC motors on a DCC layout is bad for the motor is CONFIRMED.

Now...the next experiment should be....how can we fry the motor quicker?

David B

I don't think it's a myth David. I fried a motor in a nice new decoderless Russian Decapod through leaving it sitting on a DCC powered track for less than half an hour. Little solder blobs came rattling out of the motor on opening up the loco.

[Gandy Dancer]

I would be more interested in knowing what happened to the strength of the magents in the motor.

You would have to get the magnets to heat up to 400+ degrees F to effect them.

What are you talking about?  You have obviously never worked in a scientific laboratory.  Even standard junior and senior high classroom type bar magnets can be re-magnitized in 1/120th of a second, in a standard magnitizer as below.  It was always my job to re-magnetize the school magnets after people left them in storage all summer long without their "keepers" on.
http://grauhall.com/xcart/customer/product.php?productid=901&cat=60&page=1
http://www.walkerscientific.com/Products/Product_Lines/Magnetizing_Stations/Magnetizers/XLE-Series/xle-series.html
http://www.themagnetguide.com/products/dra.html#dema
I have never had to heat anything to even close to 400 degrees to magnetize or demagnetize it.  Send me one of those "surplus" motors you have and I'll destroy the magnet in about  10 minutes without heating it at all.

[Magnum019]

I Still have a Question about this Thread and running Athearn DC's on DCC, wondering why they would run for 2 mins........then stop, I can reset them and do it all over again............I never had a problem before running the DC's (usually less then 5 mins) and just asking why if anyone can answer PLEASE??????????????

 

Cary............. 

[Flashwave]

That's the main reason I have my layout set up so I can run use DCC and DC at the same time. I can run a DCC loco in one set of blocks on DCC while I run a DC loco on another set of blocks on a DC power pack.

 

Ah, but mine was a DC oval and a DC engine. (a switch was involved, but it dead-ended into a plastic boxcar

[jeffrey-wimberly]

That's the main reason I have my layout set up so I can run use DCC and DC at the same time. I can run a DCC loco in one set of blocks on DCC while I run a DC loco on another set of blocks on a DC power pack.

[Flashwave]

Well Frap. You just answered one of my questions. Hey, when the motor went, did the headlights still work?

Yes, the lights still worked. They pick up power directly from the wheels and are not connected to the motor.

Those concerned parties out there will be happy to know that the RS3 used in this experiment have been remotored and is back in it's rightful place in the display rack.

 

Fraid you'd say that, then I guess I cn't hope my little Daylight's not just got a shot gear... Guess that bolt of lightning that went for my glasses means it died... (and that only took 3-5 minutes)

[Mark R.]

Now...the next experiment should be....how can we fry the motor quicker?

Connect it to a 110 AC plug socket. That should light it up.

That's the kind of stuff my kids would do when THEY were bored !!!

Mark.

[jeffrey-wimberly]

Now...the next experiment should be....how can we fry the motor quicker?

Connect it to a 110 AC plug socket. That should light it up.

[jeffrey-wimberly]

Jeffrey-Wimberly of Leesville, Louisiana, you need to give some consideration to taking up model railroading as a hobby; it is very rewarding although those in it too long tend to go just a little wacky!

R. T. POTEET from the far, far reaches of the wild, wild west, I think I'm already beyond that point. I'm having a really good time with it.

[jeffrey-wimberly]

Well Frap. You just answered one of my questions. Hey, when the motor went, did the headlights still work?

Yes, the lights still worked. They pick up power directly from the wheels and are not connected to the motor.

Those concerned parties out there will be happy to know that the RS3 used in this experiment have been remotored and is back in it's rightful place in the display rack.

[Hoople]

Are you killing your SP RS-3?

BAD JEFF! BAD!

No, the Santa Fe. I can always put another motor in it. I've got quite a few of them.

Oh. Go ahead and feel free to kill it. Just not the SP one.

[R. T. POTEET]

Jeffrey-Wimberly of Leesville, Louisiana, you need to give some consideration to taking up model railroading as a hobby; it is very rewarding although those in it too long tend to go just a little wacky!

[Flashwave]

Well Frap. You just answered one of my questions. Hey, when the motor went, did the headlights still work?

[jeffrey-wimberly]

I would be more interested in knowing what happened to the strength of the magents in the motor.

You would have to get the magnets to heat up to 400+ degrees F to effect them. During the course of the experiment they never got that hot. I was monitoring the motors temperature and the casing never got over 108 degrees. The brushes on the other hand, they got pretty hot. Hot enough that one of them was burned away completely and also burned part of the commutator. Resistance through the motors armature windings has increased leading me to believe that some of the lacquer coating on the windings has been partially melted, creating a short in the windings, not bad enough to prevent the motor from working but certainly enough to cut down how much electromagnetism could be created in the armature.

[jeffrey-wimberly]

Why would a man of limited resource go and burn a perfectly good motor?    Makes me wonder.....

Because I have plenty of spares in the junkbox. You forget, I've been running Athearns since the early 80's. Over twenty-odd years I've collected quite a few spare parts, gears, motors, flywheels, shafts, wheels and assorted other pieces. Gotta have a stock of spare parts to keep the fleet running you know.

[jktrains]

Why would a man of limited resource go and burn a perfectly good motor?    Makes me wonder.....

I've been thinking the same thing .  Apparently there is money to "burn" when the situation calls for it.

[jasperofzeal]

Why would a man of limited resource go and burn a perfectly good motor?    Makes me wonder.....

[Eriediamond]

I would be more interested in knowing what happened to the strength of the magents in the motor.  I've always contened that subjecting them to the reversing current would eventurally weaken them.  So even if the loco wasn't just sitting buring up its brushes (someone was actually running it on channel zero), the magnets would get weaker and weaker making the motor less and less efficient.   Unlike you I am not willing to sacrifice equipment to find out.  I guess maybe I would except I have no effective way to measure the strength of the magnets.

This sounds like a job for MYTH BUSTERS!!!!!!!!!!!!