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Engine polarity

Started by wfletcher, February 22, 2023, 10:11:25 AM

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wfletcher

It seems that different manufacturers give their engines different polarity.  Which makes it difficult with turnouts.  As it hits the new section of track on the turnout it of course reverses.
Other than switching wires on an engines polarity, is there another way to make it a continuous run without reversing?   :o 
Thnx!!!

Len

Color me confused, I've never heard of such a thing. Are you talking about the locomotive reversing direction, or the points of the turnout moving to the opposite setting?

As for the "polarity" of locomotives, the standard for non-DCC locomotives is if the right hand rail relative to the direction the loco is facing is positive, the loco should move in the forward direction. If it's negative, the loco should move in reverse.

Len
If at first you don't succeed, throw it in the spare parts box.

wfletcher

If I were to take these engines and put them both on the same track; one would go in reverse. 
This is a DC setup NOT a DCC.
I have seperate power to the turnout.  When I sent the engine to the main track it stops after going over the frog.
When I sent the train on the main track to the turn out It stops after going past the frog.
If I turn off power to either the main or the turnout and hand push the trains thru and reverse directions on both rails they go forward again without issue.
Or if I take a train off either the outside or turnout and make it so the direction is constant for which ever train, they go right thru the turnouts without issue.

Quentin

You have an interesting issue. Never heard anything like it. I don't think it has to do with polarity, though.
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VTBob

I actually have this problem with 2 separate Spectrum 2-8-0's. It seems that in my case, the last owner installed new 4pin plug wires & reverse the motor leads.

About the only way to fix your locomotive issue, not knowing what it is that you have, is to reverse the motor leads in which ever locomotive doesn't go in the same direction as the others.

Can you provide more information as to what it is that you have for locomotives?

Thanks,
VTBob
R. Montanye
Montanye Models, St. Albans, Vermont

Quentin

Well before we go switching wires 'round, make sure that is actually the problem. I've had bad experiences with switching wires...
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wfletcher

So one is a Model Power 4-6-2 steam engine that puffs smoke.
The other is a Mantua Conrail Diesel engine.
Again NOT DCC but it is DC; if you put both engines facing the same way on same track, one will go backwards the other forwards.
Thanks again for your help.

BTW, I appreciate your answers, but can't find the like button.  ::) 

Quentin

Like button is just below the last line of the message  ;)

well... whichever one goes backwards might have the wiring issue that VTBob mentioned. That's all I got, honestly.
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VTBob

Well, in my collection of shop items, & personal collection - ALL of my Model Power units run the opposite of everything else. My 3 Mantua locomotives, 4-6-4's all run the same direction as my Bachmann & BLI units.

I'd say that the only fix is to inspect the model power unit for ways to reverse the motor leads if you want it all to run the same direction as everything else. That's kind of the only way to fix that issue.

VTBob
R. Montanye
Montanye Models, St. Albans, Vermont

Len

Quote from: wfletcher on February 23, 2023, 04:34:50 PMIf I were to take these engines and put them both on the same track; one would go in reverse. 
This is a DC setup NOT a DCC.

If this is happening, one of the locos is not wired correctly. Use a multimeter to verify which rail is positive when this is happening. Whichever loco is going forward when it's right side is on the positive rail is wired correctly. The loco going in reverse with it's right side on the positive rail has the motor leads backwards from standard.

Len
If at first you don't succeed, throw it in the spare parts box.

jward

It sounds like you have far more serious problems than just a miswired locomotive.

What exactly did you mean by " As it hits the new section of track on the turnout it of course reverses."

DOes the switch itself reverse, or does the locomotive?
Jeffery S Ward Sr
Pittsburgh, PA

wfletcher

The locomotive reverse or stops.

jward

Quote from: wfletcher on February 26, 2023, 03:13:30 PMThe locomotive reverse or stops.

It sounds like you have a reversing loop situation and the locomotive is encountering a section of track where the polarity is reversed. When it stops I bet you have a dead short across the rails.
Jeffery S Ward Sr
Pittsburgh, PA

wfletcher

I wish it was as easy as a reversing loop.  Unfortunately it isn't.  I know this for 2 reasons.  If it was a dead short, my controllers would also short out.  The second reason is my volt meter.  The only time I have different current on the same rail is when the engine that goes in reverse is on the turnout.

Quentin

I say one of your locos is wired incorrectly.
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