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Engine Stalling With DCC

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  • Member since
    March 2022
  • 13 posts
Engine Stalling With DCC
Posted by mark4253 on Monday, March 21, 2022 8:41 AM
I have a model railroad that measures 17’ x 10’.  It has sat dormant for many years.  As a retirement project, I decided to revive it.  I started by changing my tracks from brass to nickel silver.  Right now I only have the yard converted to nickel silver.  The yard measures 17’ long and 2’ wide and has 6 tracks.  At the same time, I decided to convert to DCC.  I also have 10 old blue box Athearn locomotives that I wanted to convert to DCC.  After some research, I purchased a Digitrax SDH-166D.  As an experiment, I installed it in my oldest Athearn engine, a GP-30.  I was happily surprised that it worked, however, the issue that I’m having is that it does goes dead at low speeds.  Thinking that it may be that particular locomotive, I installed the same model decoder into another Athearn engine, GP-9 Fly Wheel Drive.  With this engine, while the decoder is recognized, I’m able to get sound (bells and whistles), the motor turns but the engine won’t move.  The issue seems to be similar in both locomotives.
I have my DCC set up as follows:  I have an NCE Power Cab #524025.  My track and cab bus are 16 gauge and I use Atlas terminal joiners as track feeders every 5’.  I know the recommendation may be to solder the feeders directly to the track but I’m not sure how good my skill is on this.  I purchased an NCE Auto SW so I can confidently program on the program track.
I did some research at the Dixitrax website, and they suggested power extenders but I’m not sure I want to make that investment not knowing if this will work.
So, my questions are this:  do I need a booster?  I did the “quarter test” and shorts did occur at the furthest point and everywhere in between.  Should I just purchase a new DCC locomotive to see if that will run the right way without stalling?  Should I just give up in trying to convert and invest in 10 old Athearn locomotives?  Full disclosure, other than what I mentioned here, my knowledge of electricity is very limited.  Any help you can give me would be appreciated.  Hope I have you enough information.  Thanks.
Mark
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Posted by SouthPenn on Monday, March 21, 2022 11:49 AM

Have you cleaned your track and the wheels on your locomotives?

South Penn
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Posted by maxman on Monday, March 21, 2022 12:08 PM

mark4253
the issue that I’m having is that it does goes dead at low speeds.

Assuming you are not getting a short circuit, this sounds like a dirty track/wheel issue.

mark4253
the motor turns but the engine won’t move

If you are certain that the motor is actually turning, this sounds like a mechanical issue in the drive train.

  • Member since
    November 2013
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Posted by snjroy on Monday, March 21, 2022 1:56 PM

First and foremost, I would recommmend that you replace all your brass track. Unless you clean them thoroughly before each session, they will create issues, especially with DCC. You might want to post your track plan.

About the locos, the golden rule is that your locos should be running perfectly in DC before converting them. So before converting them, you should thoroughly clean and lubricate them. In your case, if you are using old BB engines, they may have the old non-polished wheels that Athearn used in the 60s and '70s. They get dirty very quickly and the power pickup is iffy. You can buy replacements from the Athearn Website, or NWSL, I believe.

Also, you should replace the metal pieces that pick-up power from the trucks with flexible wire. The friction between the pieces is not reliable for conducting current. Two pieces of wire can be easily soldered on the metal pieces on the trucks. If you have space you can stick the decoder on top of the motor with silicone. I prefer to stick the decoder on the underside of the shell.

Are they worth converting? With a low-cost decoder (I put Digitrax in that group), you can get away with a low cost conversion. Get the 1.5 amps stall decoders. Your Athearns should have the "gold" motors - the old gray motors should be replaced. Swapping a motor is not that hard, but it adds to the cost. You should also change the bulbs to LEDs. But that's not absolutely necessary.

The new DCC engines run really smooth and have nice detail. You can't go wrong with Atlas, Athearn, Walthers or Kato. I would save up and get one or two before converting 10 old BB. That's my opinion anyway. Some people enjoy converting their engines to which they have a sentimental value. I can understand that.

Simon

  • Member since
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Posted by dennis461 on Monday, March 21, 2022 5:38 PM

You wrote, "...is that it does goes dead at low speeds. "

Please describe this better.

If you raise the throttle, does the loco move?

Does the sound stop when the loco goes dead?

Or do you have to push it to get it running.

 

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Monday, March 21, 2022 5:46 PM

First of all Welcome to the forum, your posts are delayed in moderation for a while

Second, large blocks of text are hard for a lot of us to read.  See Simon's post which is broken up into paragraphs

Third, rail joiners without feeders are notorious for not conducting electricity. 

mark4253
It has sat dormant for many years.

That can't help conduction, even with joiner feeders.  Get a package of rail joiners, a piece of sectional track.  Cut it up and add joiners and learn how to solder, before you do your layout. 

It's also a question if there is enough electricity on the track?  A cheap voltmeter set to AC is good enough to determine is you have 12 volts or 8.

There are several ways to "tune up" blue box locos, to improve pickup and conduction.  Google "Blue Box Tune Up"

I bought an inexpensive Bachman 45 tonner to see how I would like DCC.  I liked it.  However most DCC locos are much more expensive than what you paid for your Blue boxes.  They are also extremely detailed, compared to the old days.

Personally I don't need that much detail, to the point where it's hard to remove from the box, without breaking something.  I do like sound and that's an individual preference.  We have well respected forum members who hate it.  You have to decide that one yourself.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
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  • From: Mpls/St.Paul
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Posted by wjstix on Tuesday, March 22, 2022 11:18 AM

All (or virtually all) modern DCC decoders are "dual mode", meaning they will also work on DC. If it's a sound decoder, it may take a lot of power on DC to get them to move. I'd try the engines on DC. If you have the same issues, it has nothing to do with DCC, but is an issue with the engines.

BTW, besides changing out all the brass track, I'd look at changing the wheels. Even if the old engines don't have brass wheels, the old Athearn 'sintered' metal wheels don't pick up power as well as the newer ones. It's an easy replacement.

Stix
  • Member since
    March 2022
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Posted by mark4253 on Tuesday, March 22, 2022 7:29 PM

Hi!

Thanks for your reply.  The track is brand new nickel silver.  I have not cleaned the wheels because I'm not sure what is the best method to do so.  What do you suggest?

Thanks,

Mark

  • Member since
    March 2022
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Posted by mark4253 on Tuesday, March 22, 2022 7:41 PM

Hi Simon!

Thank you for your reply and advice.  Looking at the 1st engine  that I converted, it does have the gray motor.  It also has the non polished wheels.  I have the original receipt and it was purchased in 1965!  As you mentioned, replacing it will add to the cost.  All my track is newly installed nickel silver.  I think that after reading your post, I'm going to take your advice and search around for a DCC engine that is ready to run.  This way I'll know for sure if I actually have an electrical issue.  While the decoder wasn't terribly expensive, $50, I've put a lot of time in trying to get it to work; probably not worth the effort with the other 10 Athearn engines.  Thanks again.

Mark

  • Member since
    November 2013
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Posted by snjroy on Wednesday, March 23, 2022 9:47 AM

Wow, 1965...   That says a lot about the quality of those Athearn engines. A good reason to preserve some of them, IMHO. Anyway, there is nothing wrong with these old motors, they just consume a lot of amps. It is possible to make it run smoothly. I'm no expert, but I would dismantle the drive train and lubricate the motor bearings, u-joints and gears. If the motor commutator is black, you can clean it with alcohol. The wheels are an easy and cheap upgrade, I would recommend it. It may take a few minutes of running before it performs adequately. If you have a mechanical problem, you can cannibalize parts from your other engines Smile.

To clean the wheels, I take a piece of paper towel, fold it in two, soak it with alcohol, and put it on the track. I place one truck on the paper towel, and one truck on the track to make contact. Holding the engine with your hand, run the engine so that the truck on the towel gets a thorough wash (with the wheels turning). Another method is to put the loco on its back on a craddle, and use a Qtip with alcohol to clean the wheels. Two powered wires can be used to turn the wheels. I do that for my smaller steam engines.

Good luck!

Simon

  • Member since
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  • From: Mpls/St.Paul
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Posted by wjstix on Wednesday, March 23, 2022 10:06 AM

DCC decoders designed for HO scale generally are set up to handle up to 1 amp of power. An old (1965!) Athearn motor quite possibly consumes more than that. It could be the decoder is overloaded and shutting down.

Replacing the motor - even just with a newer "blue box" Athearn motor - might be worth looking into. I have some old (1990s) F7s that work fine on DCC.

Stix
  • Member since
    March 2022
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Posted by mark4253 on Wednesday, March 23, 2022 7:52 PM

Thanks for all the helpful advice.  I'm going to start by cleaning the wheels using your method.  The commutator is black.  I'll clean that as well and lubricate some of the part you mentiioned.  Hopefully, I'll get this to work.

Mark

  • Member since
    March 2022
  • 13 posts
Posted by mark4253 on Wednesday, March 23, 2022 7:53 PM

Hi!

The track is brand new nickel sivler.  I am going to clean the wheels with alcohol. Let's see if it helps.

Mark

 

  • Member since
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Posted by mark4253 on Wednesday, March 23, 2022 7:58 PM

If you raise the throttle, does the loco move?

Once it goes dead, raising the throttle doesn't help.

Does the sound stop when the loco goes dead?

Yes

Or do you have to push it to get it running.

I do have to push it to get it started again.

Mark

  • Member since
    March 2022
  • 13 posts
Posted by mark4253 on Wednesday, March 23, 2022 8:02 PM

Hi Henry!

Thanks for the welcome.

You've provided a lot of good advice.  I decieded that before I purchase a new DCC engine, I'm going to try some of the suggestions that you and some others have provided.  I've learned quite a lot about this.

Thanks,

Mark

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Thursday, March 24, 2022 11:28 AM

mark4253
If you raise the throttle, does the loco move?

Once it goes dead, raising the throttle doesn't help.

Does the sound stop when the loco goes dead?

Yes

Or do you have to push it to get it running.

I do have to push it to get it started again.

So the problem is the electrical pickup, not a problem with the decoder. I'd double check to be sure that power is being picked up from both trucks of the engine...could be one truck isn't picking up power, or it is but it's not connected to the inputs of the decoder.

You could add a Digitrax "Power Xtender" which would help.

https://www.digitrax.com/products/power-xtenders/

 

Stix

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