4-4-0 Jerky Running

[DAVISinGP]

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

[rich1998]

Which model? I have had the Richmond and American 4-4-0's in DCC and DC.

Rich

[DAVISinGP]

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.

[DAVISinGP]

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.

[bbmiroku]

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.

[rich1998]

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

[DAVISinGP]

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.

[DAVISinGP]

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. 

[Hunt]

. . . . .

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. 

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.

[DAVISinGP]

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. 

[rich1998]

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

[DAVISinGP]

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. 

[Trainman203]

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 won't believe how much crud these engines collect while running.

[DAVISinGP]

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 won't 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?

[Trainman203]

I'm not familiar with that particular engine.  But all of mine benefit from periodic treatment .