On30 Forney behaving erratically

[sirgibby44]

Hi

I wonder if anyone else is having problems with their On30 Forney .. or if anyone can offer me any suggestions

I have the Forney with Tsunami sound (Bachmann equipped)

I have had the loco from new (about 2 years) and it has not had a lot of use.
It was mainly used on DC but recently I upgraded the layout to DCC
Since changing my layout to DCC the forney has been behaving very erratically. So much so that I can no longer risk running it around the layout as it will suddenly stop in the middle of a tunnel on straight track.

Heres the scenario

- Start driving loco
- some time moves 1/4 in and stops ... other times will travel 5 or 6 feet before suddenly stopping or hiccuping
- when it stops often it will start again on its own after a second or so ... occasionally  it wont start at all until I push it.
- mostly it stops on points but also stops on straight track
- If I clean the track and points it runs better but will still stop and start erratically
- the erratic stop-start is less frequent on cleaned track


Other things I have noticed that may or may not be relevant.

- MY OTHER BACHMANN & BROADWAY LOCOS DON'T HAVE THIS PROBLEM AT ALL
- IT HAS NEVER BEEN DROPPED

- When it stops and then starts again the headlight starts flashing on and off
- Erratic behaviour happens in both forward and reverse but is worse when going forward
- Very occasionally the entire layout shorts when it stops (only very occasionally does this happen)
- When it stops on uninterrupted track (not points) it is often in the same places (straight track with no joins)
- some of the main drive wheels show pitting.


What's been done so far

- Wheel have been cleaned
- the loco has been stripped and the wheels and wiper contacts cleaned.



thanks for any suggestions

[Tim]

sirgibby44

You definitly have a short in the loco.

Check the wiring on the trailing truck, it is the most likely place for shorts
to occur.  The two wires attached to the truck may look bare but they are not.
The insulation is very thin and may have rubbed through.
On the bottom of the truck are two brass ring lugs attached to the sideframes
by small screws and extend toward the center of the truck.  they overlap at the
center of the truck, make sure the screws are tight and the lugs are not touching.
The wires are attached to these lugs.

Mark one side frame and note which side.  Pull the truck straight down to remove the truck.
It works like a dress snap.  Check the wires for bare spots or burn marks.

If you find no evidence of shorting then replace the truck opposite (180deg) from the way
you found it and test the loco on the track.  If it still shorts you will have to disassemble
the loco further to locate the short.  The short is in the power wiring before the decoder.

Or you could send the loco to bachmann for replacement.

Tim Anders
Souderton, PA

[NarrowMinded]

Not sure which wheel sets the forney uses in the trucks, but I had a side dump car that had a bad wheelset and would cause the loco to run as you described, I tore the loco apart twice before discovering it was the axle on the car that I left on the track while testing the loco. maybe one of the trucks has one of these bad wheel sets.

NM

[jestor]

You mentioned that it had been run mostly on DC.  Did/does it run OK on DC?  If so, we can go from there.

[sirgibby44]

Hi Tim

Thanks for your comments and your valuable in-depth description.

I have done as you suggested including switching the truck around but it didn't solve the problem.
However it may have bought me one step closer to a solution.
While the truck was off I tried running the loco and it ran absolutely terribly.

This tends to suggest that the problem could be with the drive wheel pick ups. (These where cleaned earlier but now deserve a closer look)
If the Drive wheels are not transmitting a good current to the loco and it is mainly reliant on the rear truck then that could explain its erratic stop/start running

regards
Michael

[sirgibby44]

Not sure which wheel sets the forney uses in the trucks, but I had a side dump car that had a bad wheelset and would cause the loco to run as you described, I tore the loco apart twice before discovering it was the axle on the car that I left on the track while testing the loco. maybe one of the trucks has one of these bad wheel sets.

NM

Thanks for the thought NM.
While the Forney is behaving erratically other locos on the layout are running fine (at the same time while testing the Forney) which would still suggest the problem is with the Forney.

Michael

[sirgibby44]

You mentioned that it had been run mostly on DC.  Did/does it run OK on DC?  If so, we can go from there.

Good thought jestor.
From memory it was fine on DC but I will go back and test it.

Michael

[JohnR]

I suggest testing with only the Forney on the layout - no cars, no other engines. 

What sort of track are you using?  And, how close are your power drops?  Lastly, how are you cleaning the rails and wheels?

Some of what you describe sounds like bad pickup.

-John

[NarrowMinded]

hey i just read a thread about isolating the motor... did you do that?


nm

[El Loco]

I turned my Forney into a 2-4-0 switcher with a scratch built slope back tender. when I first ran my Forney with the rear truck completely removed with or with out the tender it ran erratic as well  I cleaned the drivers vigorously it helped but it still wasn't 100% I soon added power pickups to the new tender for added continuity and the problem was almost solved for me. I used a Kadee wheel set cleaner then my Dremel with a wire wheel and a Q tip soaked with rubbing alcohol cleaning the drives and all wheel surfaces. It was successful.
One drawback about DCC, the track and the wheels have to be absolutely clean or they will buck like a bad mule.
That's my experience, best regards.

[hminky]

It isn't the track. The problem is in loco pickup or electrical path to the motor.

In testing:

1. If everything else runs on the track. It is the loco.

2. Test the loco with leads to the wheels to find out if it is the pickup.

Harold

[El Loco]

You had mentioned the head light flashes on and off,  Check how many flashes it makes and if there is a sequence that it flashes . Some decoders will flash the headlamp in code   to inform you where the trouble is.
Soundtraxx Tsunami has the feature I mentioned.

[miniribbet]

I have experienced the exact same DCC running (or stutter/stop) condition with my two factory sound equipped forney's. I have tried many of the suggested recommendations and nothing has worked. My gut tells me it's with the decoder itself.

[dto]

Hmm... this sounds familiar.  My Forney (DCC, no sound) began acting up the same way when on a On30 modular club layout.  At first they assumed that the engine needed lubrication or breaking in (it was purchased used and was lying idle for some time).  Another thought the drivers might be slightly out-of-quarter, since it appeared that the rods were binding.

BUT -- when tested on DC, my Forney ran as smooth as silk.  So it seems I have a similar problem.  I'm considering converting my Forney into a 2-4-0 with sound in the tender (I have a spare 2-6-0 tender, but am considering the Wisemann "shorty")  Any additional suggestions on identifying and solving this problem before I potentially fry a Tsunami?

Thanks!

David

[El Loco]

Hard wire the tsu1000 removing all factory boards. I scratch built a slope back tender for my forney-cation  now a 2-4-0 and LOVE IT!