Roundhouse 0-6-0 shorting out and motor stalling

[OWilks1]

Hi all, first post here. Just working on 2 supposed roundhouse tender 0-6-0's and they both short circuit when running for a tiny bit. One of them also has a motor that will stall and only run for a tiny bit if i give it a little spin myself. While stalled, the motor starts to get really hot as well. Would anyone be able to give me any help on how to solve these problems?

Cheers, Wilks

 

[ctclibby]

Hi all, first post here. Just working on 2 supposed roundhouse tender 0-6-0's and they both short circuit when running for a tiny bit. One of them also has a motor that will stall and only run for a tiny bit if i give it a little spin myself. While stalled, the motor starts to get really hot as well. Would anyone be able to give me any help on how to solve these problems?

Cheers, Wilks

Wilks: Take a look at brushes and commutator ( ?sp ). You should be able to erase the carbon off the commutator if it is dirty. If it is not dirty, the brushes may be worn down or not formed correctly.

Later

 

[bnsf971]

Remove the motor and make sure it runs smoothly while not installed. While the motor’s off, roll the chassis back and forth on a tabletop, and make sure the mechinism rolls freely, with no binding.

 

[Iron Horseman]

Yup, yup, what both of them said.
1. Check the brushes.
2. Check the motor separate from the chassis.
3. Check the chassis without the motor.

If none of those identify / fix the problem, unfortunately a short after running a brief time is often a problem in the motor coil where the insulation has worn off and power isn't making the full set of winds. Solution would be to replace the motor, or rewind the armature.

 

[dennis461]

Put scotch tape over the brush springs. They may be touching the boiler (if it is metal.)
Is the worm gear too tight to the spur gear on the axle?

 

[OWilks1]

Remove the motor and make sure it runs smoothly while not installed. While the motor’s off, roll the chassis back and forth on a tabletop, and make sure the mechinism rolls freely, with no binding.

The motor runs pretty well apart from the frame, but I can see sparks along the edge of the commutator as the brushes press up against it. The frame rolls for a bit, then binds up. It requires me to rotate the wheels myself to get it turning again freely, but it only goes around approx 1 turn before it binds up again. It's a bit random when it binds. Also, when I tried running it again this morning I got a short AND a puff of smoke from the commutator on both models.

 

[Iron Horseman]

The motor runs pretty well apart from the frame, but I can see sparks along the edge of the commutator as the brushes press up against it.

That would be normal. The old brushes on cummutator system always sparks some.

The frame rolls for a bit, then binds up. It requires me to rotate the wheels myself to get it turning again freely, but it only goes around approx 1 turn before it binds up again. It's a bit random when it binds.

That at least identifies where the problem is. Don't understand the electrical short, but if the running gear is binding the motor will never work right. Also confusing that the bind isn't consistent.

My next step would be to take off the rods and start one wheel at a time. Make certain they are properly quartered. try to run without the side rods just to see that the main driving wheel is smooth, then finally put the siderods and drive rods back on. At least there is no eccentric or valve gear to worry about.

 

[OWilks1]

That would be normal. The old brushes on cummutator system always sparks some.


That at least identifies where the problem is. Don't understand the electrical short, but if the running gear is binding the motor will never work right. Also confusing that the bind isn't consistent.

My next step would be to take off the rods and start one wheel at a time. Make certain they are properly quartered. try to run without the side rods just to see that the main driving wheel is smooth, then finally put the siderods and drive rods back on. At least there is no eccentric or valve gear to worry about.

I took apart the chassis and cannot see anything obvious that would be causing the problem. I dont know how to take off the rods on these kits either. I have attached a few photos and a video in case you guys could see something wrong that I cant? Also, the chassis will not bind when I apply a bit of pressure downwards when rolling it.

 

[dennis461]

You should keep the bottom plate on when testing for binding.
and
do the axles have a shim in the frame, or are they resting in the gray metal Zamac frame alone.

 

[OWilks1]

You should keep the bottom plate on when testing for binding.
and
do the axles have a shim in the frame, or are they resting in the gray metal Zamac frame alone.

I have had the bottom plate on when testing and just had it off for the sake of the video, but even with it on it still does the exact same thing

 

[OWilks1]

I have had the bottom plate on when testing and just had it off for the sake of the video, but even with it on it still does the exact same thing

Update: I attached the motor to the frame to see performance without the wheels in and the motor did a similar thing to before: small white sparks appeared where I touched the wire to and the motor only made a whirring noise and didnt move, and started to get really hot to the touch.

EDIT: I found a piece of something that fell out when taking the motor off the chassis a while back and putting that under the armature section seems to have fixed this problem. I still have another motor to do this to but I dont have another piece like this. What would it have been made of?

EDIT 2: So the motor runs one way, but spinning it the other way is much harder and it seems there is alot more friction so that it cannot move. Anyone know what could cause this?

EDIT 3: I have it running! However, it short circuits when running forwards. Backwards is fine. After working out whats causing the short, I will start working on fixing up the 2nd 0-6-0...