United 2-10-2 Motor Wiring

[NWP Dave]

This United 2-10-2 is from a collection I purchased. I want to sell it, but it does not run. Here is a photo of the motor. One wire goes to the drawbar and one to the headlamp.

Wired directly from the power pack the motor runs. Connecting to the drawbar and the terminal that has the headlamp wire it runs.

Any thoughts? There are a few more locomotives that do not run and I figure at least half the value is lost if they do not run.

Thanks,

Dave

 

[Cjcrescent]

So does this mean when the tender is connected, it doesn't run? Could be a couple of things if this is the case.

Dirty tender trucks. Dirty contact between the trucks and the frame of the tender.

Trucks reversed. The tender trucks are reversed on the tender and are not picking up from the proper side. The insulated side of the loco is usually the Lt side, (fireman's side), and the tender is insulated on the Rt side.

Other than that I don't think that any of the loco wheels are reversed in the slots. Other wise, when placed on the track, there would be a dead short.

 

[kbkchooch]

So does this mean when the tender is connected, it doesn't run? Could be a couple of things if this is the case.

Dirty tender trucks. Dirty contact between the trucks and the frame of the tender.

Trucks reversed. The tender trucks are reversed on the tender and are not picking up from the proper side. The insulated side of the loco is usually the Lt side, (fireman's side), and the tender is insulated on the Rt side.

Other than that I don't think that any of the loco wheels are reversed in the slots. Other wise, when placed on the track, there would be a dead short.

Carey may have hit the nail on the head. Tender trucks sometimes spin 180 degrees and cause a loss of pickup. I was a victim of this very recently when one of my own engines refused to run at a show!
One other thing to check. Paint on the pin the drawbar connects to. Dont know why but some folks paint them and expect them to still coduct electricity!!

 

[NWP Dave]

Thanks, I'll check it out. It would be cool if it turns out that easy.

 

[Espeefan]

Do this if reversing the tender trucks doesn't work: One side of the motor should be grounded to the frame. The other brush should be isolated (insulated from the motor frame) and connected to the wire from the drawbar. It should be the same brush that has the lead to the headlight. One side of the headlight should get power from the drawbar, the other side is probably grounded to the loco frame. Try checking each brush for continuity With the locomotive frame. Find the isolated one and wire the drawbar to it.

The photo almost looks like the drawbar wire isn't soldered to anything!

PS: failure to run does not lower the value by half! I have bought many models that didn't dun. It's usually something simple like this, and even if it's a bad motor, motors are cheap, and easy to replace. (unless you want to sell it to me for half of what you paid )

 

[PaulB]

Hi all,

this is a timely thread as I am organising my first brass loco purchase.

Can anyone explain to me the ins and outs of installing decoders on brass steamers with this sort of pick up arrangement (ie: one pole on loco and other pole through tender with both bodies live)?

Paul B

 

[kbkchooch]

Paul,
The quick and dirty is the engines commonly pick up on the right side, tenders on the left.
The drawbars are the link between the 2.
Its pretty standard, not only for brass but also for cast metal steamers too. Like Mantua,Bowser etc

 

[PaulB]

Karl,

what I am thinking is that there would be a higher chance of short circuits if the loco frame and tender are live. Is it common practice to isolate the bodies by building a new pick system?

Now the tricky thing here that I see is the need to replace wheels with isolated equivilents. For this reason, I'm thinking maybe just run with the live body idea. I hope short circuits won't burn out too many decoders.

Paul B

 

[Espeefan]

Brass must be tuned to the layout it runs on. I have run for many years and not had problems with shorts between the loco & tender once the initial debugging has been done. You can get a short if double heading brass steamers unless your couplers are isolated or plastic. Other than that, mine run fine. They do tend to be less forgiving of tight minimum radii. Don't expect to run a brass 4-8-4 around an 18" radius curve.

 

[kbkchooch]

Karl,

what I am thinking is that there would be a higher chance of short circuits if the loco frame and tender are live. Is it common practice to isolate the bodies by building a new pick system?

Now the tricky thing here that I see is the need to replace wheels with isolated equivilents. For this reason, I'm thinking maybe just run with the live body idea. I hope short circuits won't burn out too many decoders.

Paul B

Paul,
Never been an issue with shorts with live frames, unless as Alan pointed out, you are doubleheading steam.
I think you would have a harder time insulating the frame and using a wiper system instead!

 

[Cjcrescent]

Paul,
...
I think you would have a harder time insulating the frame and using a wiper system instead!

I can assure you that adding extra pickups to a brass steamer, while not impossible, is alot more work. Stay with the frame pickup and you'll do just fine. And as long as it's not a short framed switcher, you'll have no problem with the dead frogs on DCC "friendly" turnouts. I've have more problems with cast boiler locos, like Bowser, MDC kits than with the brass.

Would also recommend that you do a stall test on the motor, if it's an open frame motor. With a can motor the brushes are already insulated from the frame so no need to isolate the motor itself.

 

[NWP Dave]

So does this mean when the tender is connected, it doesn't run? Could be a couple of things if this is the case.

Dirty tender trucks. Dirty contact between the trucks and the frame of the tender.

Trucks reversed. The tender trucks are reversed on the tender and are not picking up from the proper side. The insulated side of the loco is usually the Lt side, (fireman's side), and the tender is insulated on the Rt side.

Other than that I don't think that any of the loco wheels are reversed in the slots. Other wise, when placed on the track, there would be a dead short.

The locomotive does not run with or without the tender. I cleaned the wheels, and trucks to tender. Tender is insulated on the right side.

On a test track I connect power directly to the drawbar and have power to the track. No movement. Then, leaving the power connected to the drawbar and touching the terminal where the headlamp is wired, the locomotive moves.

I did open up another locomotive that has the same pittman motor to see how it is wired. It is wired opposite of the one I'm trying to get to run. The problem is, it doesn't run either.

 

[kbkchooch]

The locomotive does not run with or without the tender. I cleaned the wheels, and trucks to tender. Tender is insulated on the right side.

On a test track I connect power directly to the drawbar and have power to the track. No movement. Then, leaving the power connected to the drawbar and touching the terminal where the headlamp is wired, the locomotive moves.

I did open up another locomotive that has the same pittman motor to see how it is wired. It is wired opposite of the one I'm trying to get to run. The problem is, it doesn't run either.

ok the tender sounds ok.
1st things 1st, which rail was hot when you applied current to the drawbar,,,the engines right side???

Got an ohm meter or a continuity checker??

Wanna sell them as-is?

 

[Cjcrescent]

Dave,

I pulled one of my old Pittman motors out and looked at it. I compared it to your picture. It was identical.

So this is my thinking now. The headlight wire looks like it was attached to the brush spring at some time later than when it was built, and this has resulted in a bad cold solder joint with the plate. IOW the plate doesn't contact the spring. The repair is easy. Resolder the end of the "headlight" spring to the copper plate.

It should run properly now. Test by attaching a power lead to the drawbar, and then touching the other lead to somewhere on the frame where you can see bare metal, like the valve gear frame, screws holding the VG frame in place etc.

 

[kbkchooch]

Dave,

I pulled one of my old Pittman motors out and looked at it. I compared it to your picture. It was identical.

So this is my thinking now. The headlight wire looks like it was attached to the brush spring at some time later than when it was built, and this has resulted in a bad cold solder joint with the plate. IOW the plate doesn't contact the spring. The repair is easy. Resolder the end of the "headlight" spring to the copper plate.

It should run properly now. Test by attaching a power lead to the drawbar, and then touching the other lead to somewhere on the frame where you can see bare metal, like the valve gear frame, screws holding the VG frame in place etc.

You still got Pittmans??



Wow Carey,, you ARE old!! But the antique repair sounds logical!

 

[Cjcrescent]

You still got Pittmans??

Wow Carey,, you ARE old!! But the antique repair sounds logical!

Keep a couple around for sentimental reasons. They are actually, for open frame motors, some of the best runners around, as generally their torque couldn't be beat. After the armatures are treated, the shaft, windings/commutator and such are removed and balanced, then re magnetizing the magnet after reassembly, and finally adjusting the brush springs so the brushes friction load is almost completely eliminated, then you have gone from a excellent motor, to an outstanding one. I have one of the old DC95's or DC195's, (see my half-hiemers is kicking in!) in my Hobbytown PA. The motor was used in O scale brass. It fills up the entire back end of the locomotive. Has 7 poles and will stall at .90 amps. At full speed, the amp draw is about .30 amps. If I was still running DC, I'd be replacing any non-can motors with Pittmans.

As to me being old, I had to ask my younger brother Methuselah, exactly what my age was. He forgot!