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What makes a loco travel in the wrong direction?

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Posted by SeeYou190 on Friday, September 16, 2022 5:56 PM

crossthedog
Kevin, what is a split frame? Do you mean the frame of the motor?

A split frame has the frame divided into two halves, left and right, and seperated by plastic insulators and held together with plastic screws. Each half of the frame makes up a different part of the electrical circuit. The motor leads will each be connected to one of the frame halves. This style frame was first used on Kato-built N scale locomotives and was very reliable electrically. It did make DCC installations difficult because the motor was almost impossible to isolate from the frame.

A "typical" frame has one half of the electrical path going through the frame, and the other to isolated leads on the trucks. This is the good old Athearn Blue Box style of electrical pathways that has been copied by so many HO model builders. With this style frame, if the trucks are swapped, the "grounded" side of the circuit is on the wrong rail, and the locomotive (DC) will run reversed.

-Kevin

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Posted by SeeYou190 on Friday, September 16, 2022 5:54 PM

Dots - Sign

Double post. Sorry.

-Kevin

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Posted by jjdamnit on Friday, September 16, 2022 5:53 PM

Hello All,

What a challenge- -indeed!

The color coding on the existing wiring would be a nightmare to diagnose/trouble shoot.

I would completely disassemble the locomotive and upgrade the wiring to current NMRA standards, even if the final assembly is for DC.

During this process, you can clean and inspect the rest of the unit.

When you reassemble the motor wiring, drivetrain and lighting should make it easier to find a solution. 

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by crossthedog on Friday, September 16, 2022 5:51 PM

richhotrain
Now I don't know what to say, Matt. Laugh It is curious because I was searching the Atlas website for more information which led me to look for the manufacture date, and that's when I wound up looking for your particular road number.

No harm no foul, and I'm especially touched since you were actively doing research in pursuit of a solution on my behalf.

I just a while ago said I was going to try reversing the trucks, but I wanted to get an answer about what a "split frame" is before I try that. Kevin said if it's a split frame then reversing the trucks won't work, and that virtually all the Kato locos had a split frame. Although... this is made in China (says so on the chassis), so even though it's Atlas it wouldn't be a Kato engine, right? It would be the Sino-knock-off.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by richhotrain on Friday, September 16, 2022 5:44 PM

A little more searching and I found an Atlas Classic Northern Pacific RS-1 #803 on Worthpoint, so my bad. Not sure though why it doesn't show up in HO scale on the Atlas website.

Rich

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Posted by richhotrain on Friday, September 16, 2022 5:33 PM

crossthedog
 
richhotrain
1. The only Atlas RS-1 in the Northern Pacific road name with #803 is an N scale. That locomotive was manufactured in October, 2002. Is your locomotive N scale? 

Rich, I don't know what to say to this, except that I've been watching this same HO scale Atlas Classic Northern Pacific #803 locomotive for more than a year on eBay and other websites, and I also am sitting right next to it right now, and the 803 is factory painted right on the cab.

Now I don't know what to say, Matt. Laugh

It is curious because I was searching the Atlas website for more information which led me to look for the manufacture date, and that's when I wound up looking for your particular road number.

Rich

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Posted by crossthedog on Friday, September 16, 2022 5:26 PM

selector
f this engine goes in the same direction, no matter which way it is lifted, turned 180, and set back on the rails, it is a DC setup.

Yes. DC, both the locomotive and the operation.

SeeYou190
I can't really tell from your picture if this model has a split frame or not. If it has a one piece frame, and the motor has one lead "grounded" to the frame, then most likely the trucks are reversed. Swap the trucks with one another and it should be OK. If it has a split frame, like most Kato locomotives, this will not work.

Kevin, what is a split frame? Do you mean the frame of the motor?

richhotrain
1. The only Atlas RS-1 in the Northern Pacific road name with #803 is an N scale. That locomotive was manufactured in October, 2002. Is your locomotive N scale?

Rich, I don't know what to say to this, except that I've been watching this same HO scale Atlas Classic Northern Pacific #803 locomotive for more than a year on eBay and other websites, and I also am sitting right next to it right now, and the 803 is factory painted right on the cab.

It's clear to me now that someone removed the board from this locomotive. I see this board on the diagram that Stix provided a link to, but there's nothing like that under the hood here. Also, I believe the Accumate couplers have been replaced because these look like Kadees to me. So, clearly some monkeying has occurred.

I believe I will try swapping the trucks first. If the couplers have been replaced, it makes sense that the trucks had to come off, and maybe the previous owner sold it before he noticed he'd put the shoes on the wrong feet.

-Matt

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by richhotrain on Friday, September 16, 2022 5:08 PM

A few comments.

1. The only Atlas RS-1 in the Northern Pacific road name with #803 is an N scale. That locomotive was manufactured in October, 2002. Is your locomotive N scale? 

2. There is no light board because the previous owner apparently took it out and hardwired the locomotive.

3. The only logical explanation is that the motor is wired in reverse. If it is, That red wire appears to connect to ground (negative) on the metal frame. There also appears to be a black wire (positive) leading to the underside of the motor. Those two wires would need to be reversed to correct the direction, if that is indeed the problem.

Rich

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Posted by SeeYou190 on Friday, September 16, 2022 4:51 PM

I can't really tell from your picture if this model has a split frame or not.

If it has a one piece frame, and the motor has one lead "grounded" to the frame, then most likely the trucks are reversed. Swap the trucks with one another and it should be OK.

If it has a split frame, like most Kato locomotives, this will not work.

-Kevin

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Posted by selector on Friday, September 16, 2022 4:50 PM

If this engine goes in the same direction, no matter which way it is lifted, turned 180, and set back on the rails, it is a DC setup.  A decoder would make it run the same way, with the new 180 orientation.  So, long hood, short hood, whichever way it ran 'fwd' previously, that end of the loco will move 'fwd' again.  Meaning the other way down the tracks.

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Posted by crossthedog on Friday, September 16, 2022 4:15 PM

wjstix
Inside, the engine should have a green "light board" with two wires on one side, near the middle. Those are the wires going to the motor. Disconnect them, and reconnect them the other way around.

stix, here's the belly of the beast (for full resolution, click open, close, then open image again):


Just what wires are we talking about here? I don't see the green light board you mentioned. The white and black wires go up to the clear plastic apparati in the hood that distribute the light to each end of the locomotive.

 

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Posted by wjstix on Friday, September 16, 2022 2:08 PM

You can lift the body off of the chassis, leaving the walkways and railings as they are, but you need to disconnect where the railings connect to the cab.

Inside, the engine should have a green "light board" with two wires on one side, near the middle. Those are the wires going to the motor. Disconnect them, and reconnect them the other way around. That will reverse the direction so it will go the same direction on DC as your other engines. Unless someone soldered the wires, the wires should just be connected with rubber "wire retainers" so it's very simple to do.

http://download.atlasrr.com/pdf/HO%20ALCO%20RS1%20LOCO.pdf

 

Stix
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Posted by crossthedog on Friday, September 16, 2022 10:41 AM

I need to clarify. I'm not talking about which hood forward. It doesn't matter which end is facing where. If I pick up the engine and point it the other direction and set it back down on the track and throttle up again, it still goes in the same direction. What I'm saying is that if I put several locomotives on the track at once and throttle up, all the others will head north and this one will head south.

betamax
You don't mention if you are running DCC or DC or if the loco was preowned.

I'm running DC. The locomotive is preowned. Got it at a swap meet; no box, but it's the Atlas Northern Pacific RS-1 #803, which has almost no chance of being anything but the black box Classic model.

I have not looked inside it to see if someone put a decoder in it or added anything else, but the guy who sold it to me -- I have bought many things from him at previous shows -- would surely have told me if the locomotive was DCC-ready or equipped and would have charged accordingly.

The trucks obviously don't spin around like the trucks on my old Roundhouse tender (which would simply make it not run), so I guess the task is to pop the hood.

Thanks for the clues, all.

-Matt 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by wjstix on Friday, September 16, 2022 8:54 AM

Many real railroads ran their first generation engines long-hood forward. However I believe all Atlas Alcos (RS-1, RS-3, RS-11 etc.) come from the factory wired up with the short hood being the front. They may all use the same chassis / motor etc. so it was easier to do it that way? In any case, Atlas doesn't differentiate which railroad ran long-hood and which ones ran short-hood first, all the models are set-up short hood.

If you're running it on DC, you can disconnect the two wires connecting the motor to the lightboard, and reconnect them reversed. If it's a DCC engine, just read the value in CV29 and add 1 (so if it's "6", reprogram it to "7").

Stix
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Posted by snjroy on Friday, September 16, 2022 8:09 AM

Are you sure it is backward? I believe it depends on the road. Some ran them short nose forward, some long nose forward.

Simon

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Posted by dehusman on Friday, September 16, 2022 6:35 AM

Or turcks reversed, depending on how the engine is wired.

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Posted by betamax on Friday, September 16, 2022 6:07 AM

crossthedog

I came into possession last weekend of a China-made Atlas Classic RS-1. It's a smooth runner, as I knew it would be. However, it runs the opposite way down the track from every other locomotive I have. What makes it do that? Are the trucks reversed, front and back, or each spun 180 degrees? Or is the motor mounted the wrong way (I wouldn't think it has been altered from its factory condition)? What's the fix for this?

Thanks in advance.

-Matt

 

You don't mention if you are running DCC or DC or if the loco was preowned. In DC, if it were indeed running the wrong direction, the motor wires are reversed.

In DCC, someone could have altered the NDOT bit in CV29 to reverse direction from its normal default.

Using the NDOT to correct a wiring mistake is a bad practise, as it can be altered when consisting.

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Posted by NVSRR on Friday, September 16, 2022 5:40 AM

When it is moving, which end has the head light on?

maybe somebody installed a duel decoder and in dc mode, it reveals the motor leads are wired backwards.   Or somebody did have it open and put the motor leads onto the motherboard backwards.   
if the headlight goes on in the direction of travel, then it isn't a motor lead issue.  Something else is.  Those frames and made in such a way that the motor only fits one way.  So it can't be installed backwards.  Even if it was, it would make no difference anyway.

 

shane

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An optimist sees the light at the end of the tunnel

A realist sees a frieght train

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Posted by doctorwayne on Friday, September 16, 2022 12:52 AM

I'm not much of an electronics wizard, but my guess is that the wires soldered to contacts on the motor need to be reversed...worth a try, anyways.

Wayne

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What makes a loco travel in the wrong direction?
Posted by crossthedog on Thursday, September 15, 2022 11:18 PM

I came into possession last weekend of a China-made Atlas Classic RS-1. It's a smooth runner, as I knew it would be. However, it runs the opposite way down the track from every other locomotive I have. What makes it do that? Are the trucks reversed, front and back, or each spun 180 degrees? Or is the motor mounted the wrong way (I wouldn't think it has been altered from its factory condition)? What's the fix for this?

Thanks in advance.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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