Help me fix my Mantua 0-4-0

[XavierJ123]

Sunday, I purchased a used Mantua 0-4-0 at the Cincinnati Train Show. When I got a chance to try it out at home it ran sporadically and then stopped. I took it apart and tested the engine and was delighted to see it run just fine---full rpm. I cleaned, lubricated and checked a wire that runs from the engine to the tender and everything seems okay. I reassembled the parts and put her on the track and it doesn't run. Well, it moved five inches and stopped. Now what? :cry:

 

[XavierJ123]

It works now---------

When I run into a model railroad problem that I can't solve, I have found that it is best to quit for the day and approach the problem the next day. So this morning, I disassembled the Manuta 0-4-0 again to inspect the "inner workings". I am not sure exactly what I did, but I inspected the running gear to see if anything was binding and kept moving parts until it seemed like everything was moving smoothly and okay---whatever that means???? Then instead of "completely" reassembling the engine, I left the top part of the locomotive off so I could watch the little electric motor match up to the gears for the wheels---on the track. It was kind of neat to see the inner workings of a model locomotive as I applied electric power from the transformer. Surprise, surprise! It worked. It began to run around the track---as smooth as an old 0-4-0 could. My only concern now is that I have to turn up the transformer to almost full power (full throttle) to make it run at a medium speed; compared to my other locomotives which move at the same speed at half that power (half throttle). You can smell the little motor and I am not sure what that means. What do you think?

 

[ezdays]

Just a thought, but if you're smelling the motor, that means it could overheating and could very quickly start to smoke, then burn out. It is a possibility that your motor has an excessive load on it. From what? I don't know, it could be in the gears. It could be too much grease making the motor work harder or maybe you have a gear out of alignment and it is binding. It could even be the motor brushes or a dirty commutator, if this is the case, you will smell something other than a smoky or hot smell,. I would not run this loco at full power, or more than just a little power until you find the problem or you could lose the motor.

Good luck, these are just a few thoughts that came to mind, maybe someone else can pin it down closer. But, let us know if you find anything.

 

[Ray Marinaccio]

A number of things will make the Mantua motors run slow.
Check for binding, and dirty commutator and brushes as Don mentioned.
If the brushes were oil soaked you may need to scrape off the top layer of burnt carbon from them. Polish the commutator with a Bright-Boy or 600 grit sand paper. and carefully clean out the grooves on the commutator with a hobby knife.
The brush spring tension could be weak. Test this by applying pressure to each brush with a screwdriver and see if the rpm increases.
I have found that some of the magnets loose their magnetism with age.
test this by touching another magnet on a pole of the original magnet and note if the RPM increases substantially. If the motor slows, use the other pole of the magnet.
If none of this helps and the motor is running hot the armature could be burnt and needs replaced.
Hope this helps, these are nice running locos when tuned properly.

 

[XavierJ123]

Thanks for a plan of action--------

Thanks for all the advice. I ran the little engine again today for quite a while; maybe 30 minutes. It only moves at full throttle which you said not to do. I think what I need now is a diagram of an electric motor so I can learn the parts of an electric motor. Then I think I can try the different inspections you all suggested and determine what is going on. Altho I am disappointed in the engine so far, I am enjoying the opportunity to learn something about model train engines. I was thinking tonight that the little engine might have been in storage so long that it just needed a good running. I took one of my engines out of storage last Christmas and it didn't move at all. However, after freeing the ceased motor it ran fine. This one, however, does not run fine; the speed varies on its' own, almost kind of jerky but not jerky; steady then faster, then slower, then faster, etc. I think I will clean the track tomorrow with alcohol.

 

[MasonJar]

Xavier...

The other thing to remember is that the little 0-4-0 is a switcher-type designed for low speeds and small loads. It will (should?) not run as fast as other engines with the same power - the gearing is (should be) different.

Here's a diagram of an electric motor:
http://electronics.howstuffworks.com/motor1.htm


And here is a neat one about how to build a (very) simple electric motor:
http://www.exploratorium.edu/snacks/stripped_down_motor.html

Andrew

 

[XavierJ123]

I sprayed some electrical contact cleaner on the motor last night and ran it some more without any improvement. I found the same websites with the diagram describing the parts of an electric DC motor. It took me forever to find a website with a picture of a real motor and indentification of its' parts. I thought maybe the problem was the pickup wheels on the tender as I thought I noticed some increase in rpm when I pushed down with my finger on the tender while the engine and tender was running around my small oval test track. I can't figure out how to open the tender to inspect the wiring inside but was able to check the continuity of the wiring from the engine wire to the pickup wheels and everything seemed okay. Back to the drawing board. You know, I also connected "just" the disassembled engine directly to a transformer on a test track ( thus bypassing electrical pickup from its' tender ) and it runs like gang busters---just fine---that's why I suspect it has something to do with the electrical pickup from the tender. But I don't know how the tender comes apart. It has three little silver beads that look like a drop of solder. Are these rivets? There are no screws except on the trucks.

 

[Ray Marinaccio]

I thought maybe the problem was the pickup wheels on the tender as I thought I noticed some increase in rpm when I pushed down with my finger on the tender while the engine and tender was running around my small oval test track.

That reminds me,
Try removing the trucks and cleaning the bolsters and tops of the trucks. If there is oxidation at that point it will create resistance under load and reduce the voltage to the motor.
I have soldered jumper wires to the trucks and conected to the drawbar screw on some of my Mantua locos to improve their preformance.

 

[XavierJ123]

I sprayed some more of the CRC QD Contact Cleaner on the engine per the instructions and ran it again the next morning. I must have really cleaned parts as I was hearing "squeaking" as the 0-4-0 engine moved around the track. It kept picking up speed to a point where I had to back off the trottle. I next tried "teeny tiny drops of oil on the moving parts (wheels & trucks) that I suspected were squeaking. I also used a bit of silicone spray with some success and finally resorted to a dab of WD-40. The latter did the job and it began to run successfully at half throttle. So I believe between the cleaning with the electrical contact cleaner and the lubrication, the engine is now running fine. I think I have done everything but clean the bolsters. I did lubricate the trucks. I would recommend the QD Contact Cleaner that I found at Home Depot. It seemed the most promising right off the bat.

 

[ezdays]

Good to hear you had success.

 

[XavierJ123]

Final report--I ran the Mantua 0-4-0 again this morning and I immediately had to back off on the throttle as the little engine now picks up speed rapidly. I attached a consist of 4 cars and a caboose suspecting that it would have trouble pulling but it didn't seem to make any difference. As a matter of fact, I think the weight of the car behind the tender might have improved the contact of the rear truck on the tender thus improving the electrical contact there. The tender is sloped to the rear so I don't think there is much weight over that rear truck and attaching a car sort of holds it down--IMHO. At any rate, I hope someone can use this bit of information to get an engine running that has been in storage for ages. Thanks again for all the help.