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Discussion Boards => General Discussion => Topic started by: DAVISinGP on January 29, 2019, 03:19:08 PM



Title: 4-4-0 Jerky Running
Post by: DAVISinGP on January 29, 2019, 03:19:08 PM
Weird problem with my HO 4-4-0:

Suddenly it's very jerky when it runs. Sometimes it just stops. The odd thing is that it runs great in reverse.

I think a lube may be in order, so, as a relative newbe, I'm trying to locate instructions to do so.

Any other ideas would be appreciated.

Thanks,

Pauley


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 29, 2019, 04:49:20 PM
Which model? I have had the Richmond and American 4-4-0's in DCC and DC.

Rich


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 29, 2019, 05:03:26 PM
Hi Rich,

It's #52704 - DCC American

This guy:

https://shop.bachmanntrains.com/index.php?main_page=product_info&cPath=258_276_978&products_id=5934&zenid=r45sqg0oq5mo6q2ut326ptnpt1

I already sent it back once a few months ago for a wobble/derailing problem that was repaired.


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 29, 2019, 07:42:20 PM
Well, I found several good videos on lubrication so I guess I'll give that a try.

It's just so weird that it runs flawlessly backwards - I'd be interested if anyone has a theory on that.


Title: Re: 4-4-0 Jerky Running
Post by: bbmiroku on January 30, 2019, 08:13:35 AM
It may be too much play in your rotor.  Assuming there is an AC motor approximately where the firebox would be, the rotor probably has a worm on one end that spins a vertical gear (worm gear) on (or connecting to) one of the driving wheels.  In reverse, the worm gear pushes the rotor slightly into the motor, creating a better pick-up for power through the magnetism.  In forward, the gear pulls the rotor slightly out of the motor, creating less power pickup.
If you have the paperwork for the engine, including the parts list and diagram, there should be something called a thrust bearing or thrust washer, something on the end of the motor's axle to stop 'slop', or the back-and-forth movement of the rotor when the train is moving.  If there isn't, 1) Bachmann might want to put one on from now on, and 2) take it to a hobby shop and they should be able to size you for one.


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 30, 2019, 11:03:38 AM
The motor is DC but is powered by PWM from the decoder.
Good trouble shooting. That is what I would have done. I do not have that model. I have the older tender drive models. I had to fine tune mine and converted them to DCC and add pickups to the tender years ago. You might want to add pickups to the tender.

Rich


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 30, 2019, 11:12:08 AM
Wow, you guys know your stuff. Thanks for your analysis.

With my very limited capabilities, I'll take a peek and see what I can see.

Note that it had been running fine for months.

BTW, I do have a parts diagram, although it does not "list" the parts - only numbers.


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 30, 2019, 01:27:29 PM
Well, I spent some time watching the little guy, and noticed that he had a problem mainly in curves and on switches, once again, only going forward. But when he stalled, if I gave the tender a little touch, he'd start going again. I figured it might be a contact/current issue.

I had already cleaned the track. So what I did was to put a tiny drop of conductive oil on the inside of each of the tender's wheels. Incredibly, after a couple of little hiccups, he woke up and has run flawlessly for the past 15 minutes.

Not sure if this was a permanent cure, but it tells me something - although I don't know what.  ;D


Title: Re: 4-4-0 Jerky Running
Post by: Hunt on January 30, 2019, 03:40:58 PM
. . . . .

I had already cleaned the track. So what I did was to put a tiny drop of conductive oil on the inside of each of the tender's wheels. Incredibly, after a couple of little hiccups, he woke up and has run flawlessly for the past 15 minutes.

Not sure if this was a permanent cure, but it tells me something - although I don't know what.  ;D

Tells you cleaning track is only part of required maintenance.  Cleaning locomotive and tender wheels, electrical pick-up contact points and proper lubrication of the locomotive also required.


 


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 30, 2019, 04:00:40 PM
Tells you cleaning track is only part of required maintenance.  Cleaning locomotive and tender wheels, electrical pick-up contact points and proper lubrication of the locomotive also required.
 
No question about it, that's very true.

However if the problem isn't resolved, I'll still have more to learn.  ;)


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 30, 2019, 07:53:40 PM
The microprocessor on a decoder is very sensitive to any interruption of the DCC signal and will reset if it looses the signal. The is why tracks, wheels and  pickups have to be clean.
Below is a link from Minky I have.
I did this some years ago with my older tender drive Bachmann, IHC and Mantua 4-4-0 that I converted to DCC.

http://www.chainsawjunction.com/1879/nt_440/wipers/

Rich


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 30, 2019, 08:06:39 PM
Thanks for that info, Rich. To be honest, that procedure is a bit beyond my current capabilities. But at least I now know what I'm dealing with.

And if you're ever in southern Oregon, I'll supply the refreshments if you supply the talent.  ;)


Title: Re: 4-4-0 Jerky Running
Post by: Trainman203 on January 30, 2019, 08:29:55 PM
Put the engine upside down in a cradle of some kind.  Get a spray air can that you dust PC keyboards with.  Put jets of high velocity air up all around the drivers and be amazed at all the dust woofies that fly out.  Some were probably lodged in the pickup wipers occluding the forward position on the drivers.  Do the same thing under the tender. 

See if this helps.  Do it every few months .  You wonít believe how much crud these engines collect while running.


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 30, 2019, 08:39:12 PM
Put the engine upside down in a cradle of some kind.  Get a spray air can that you dust PC keyboards with.  Put jets of high velocity air up all around the drivers and be amazed at all the dust woofies that fly out.  Some were probably lodged in the pickup wipers occluding the forward position on the drivers.  Do the same thing under the tender. 

See if this helps.  Do it every few months .  You wonít believe how much crud these engines collect while running.
Thanks for the suggestion.

Dumb question, but the current feeds through the wheels of the tender, right?


Title: Re: 4-4-0 Jerky Running
Post by: Trainman203 on January 30, 2019, 10:16:49 PM
Iím not familiar with that particular engine.  But all of mine benefit from periodic treatment .


Title: Re: 4-4-0 Jerky Running
Post by: Hunt on January 30, 2019, 10:53:21 PM
[. . .

Dumb question, but the current feeds through the wheels of the tender, right?

Current does feed from rails through the wheels of the tender and also the locomotive wheels.

Some research for you  -- Study the exploded view diagram included with the locomotive (it's also online) -- see if you can spot the wheel current pickup wipers and then local them on the locomotive.  Something for later, using a multimeter,  you can determine if the wipers are working as they should.



Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 30, 2019, 11:14:12 PM
Dumb question, but the current feeds through the wheels of the tender, right?
[/quote]\

Yes. You can see the metal wipers that pickup current from the wheels. Bachmann tenders pickup from one side one one truck and the other side one the other truck.

Minky's fix helps pick up from all wheels. With DCC, all wheel pickup helps as well as stay alive clean track, wipers, wheels. Those who keep track clean generally do not need stay alive if they have powered frogs. Your mileage may vary.
My home layout had handmaid turnouts as well as the club so no issues with turnouts.

Thanks. I live in Western MA. I will never get out that way.

Rich


Title: Re: 4-4-0 Jerky Running
Post by: bbmiroku on January 31, 2019, 01:48:53 AM
Since it's a relatively small engine, it probably feeds from the tender wheels and the big wheels on the engine.


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 31, 2019, 03:32:46 PM
Since it's a relatively small engine, it probably feeds from the tender wheels and the big wheels on the engine.

Take a few minutes to look at the diagram page for any Bachmann loco. You will see the pickups for the wheels.

Rich


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 31, 2019, 03:56:36 PM
https://www.bachmanntrains.com/home-usa/dwg/dwgs/HO4-4-0AMERICAN_CHASSISASSEMBLY(DCCSOUNDVALUE).pdf

To be honest, I can't tell which part you are referring to.

If the loco picked up juice, wouldn't it run without the tender? Mine won't.


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 31, 2019, 04:13:25 PM
The pickups are on the tender axles and drivers. The decoder sends PWM to the motor in the loco.
Two wires from the drivers send DCC to the decoder along with DCC from the tender pickups.
DC from the decoder to the headlight.
Standard for all Bachmann locos.
If you look at decoder instructions you see seven wires for non sound decoders. NMRA standard.
Some have more for extra lights and two for speaker.

Some can stick a non sound decoder in a loco.

RIch


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 31, 2019, 04:24:42 PM
Thanks for that info.

Man, I shouldn't have slept through all those classes.

 ;)


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 31, 2019, 04:34:58 PM
OK, Not sure how familiar you are with the Bachmann parts are. I think I got it right.
Tender. Pickups. BA024#MT18
Be advised, some Bachmann steamers, the tender trucks can swivel 180. That can cause a short to the DCC system. No idea about this one.

https://www.bachmanntrains.com/home-usa/dwg/dwgs/HO4-4-0AMERICAN_BODYASSEMBLY(DCCREADY).pdf

loco pickups. MT 19 MT 20

https://www.bachmanntrains.com/home-usa/dwg/dwgs/HO4-4-0AMERICAN_CHASSISASSEMBLY(DCCSOUNDVALUE).pdf

Rich


Title: Re: 4-4-0 Jerky Running
Post by: DAVISinGP on January 31, 2019, 04:52:24 PM
I can see that.

To be honest, I haven't spent much time looking at schematics. I sure wish I could apprentice in locomotive assembly to learn this stuff. I've got to admit to a fear of taking anything that small apart. (Actually, I guess the real fear is having to put it all back together after I take it apart.  ;D)


Title: Re: 4-4-0 Jerky Running
Post by: rich1998 on January 31, 2019, 05:11:47 PM
I know what you mean. I have been doing that for many years. I guess you have to start some where but I did with DC stuff many years ago. A lot different today with DCC and all the details one the steamers.

RIch


Title: Re: 4-4-0 Jerky Running
Post by: bbmiroku on February 03, 2019, 02:10:45 AM
Take side-view pictures of what you're taking apart before you take it apart.  That way you put the wheels back on right.  If it doesn't want to come apart, don't force it; it may not be meant to come apart or you may be missing something.
Follow those rules and you should be fine.