Post #2! I Have an Atlas GP-7 That has begun to run poorly: the LED remains on but the engine will not run. This same type of thing has happened to several other train engines I have. Each one of them I found to have a build up of brush metal in the cracks in between the 3 or 5 motor contacts, shorting the motor. I took the engine apart and first I did an Ohm check on the motor while spinning the shaft, It had 3 ohms ressistance. Looking closer I could not easily destinguish between motor contacts and the cracks in between them. I cleaned the brushes and that got the train running (I think it might have been because one of them was sticking inside its tube). What I want to know is whether or not it was the brushes and/or the Atlas motor has cracks in between and if so is there a good cleaner to get rid of the grime? Thanks
Any electrical motor that uses carbon brushes will, over time and use, need to have the comutator cleaned. That's part of basic maintenance that should be performed periodically. The frequency of which would depend on how often and how hard you work your engines. A good electronics cleaner or good ol' alcohol will do the job, just don't get it on any painted surface. Dean
I have a question along this line. I have an old metal Mantua Pacific that had wornout brushes. My Dad replaced the carbon brushes with graphite brushes that he made from a small block. This engine is still running fine today, after thirty years or more. Question: Is graphite a better brush material than carbon? They do not look to be worn at all, but maybe they also fill the commutator grooves? I know graphite makes good bearings, like the clutch throwout bearing on my Ford Pickup.
Graphite is carbon. For uses such as motor brushes I believe it is compressed together with a binder. What your dad used was probably harder than the original material used. You must have run that Pacific a lot! Cheers, Rod Schaffter
Watash, In my shop when at all possible I use Graphite to make brushes! I don't like the carbon ones as they do get pretty cruddy in time from running. BUT the graphite ones are really hard an last 10 times as long. and not to mention it takes some massive voltage in amps to burn a graphite brush! I'm eventually going to replace all the brushes in my loco's with graphite ones for this very reason! I do basic tune ups and all but the graphite brushes are a whole lot better for brush materials! And may I recommend a good cleaner for all you guy's loco motor comutators, I clean mine first with a small fast spinning BRASS wire wheel on my Dremel! DO NOT I repeat DO NOT use a steel wire wheel or any other type wire wheel in a Dremel for this!!!! They will scratch the contact plates of the comutator where a BRASS wire wheel will not! Brass wire wheels are known for polishing metals and not scratch it! This removes the grime and all from the comutator, then take an clean out the groves with the unsharp side of a no. 11 exacto knife blade, and rub alittle alcohol on it with a lint free cloth, and then dip a good (new) pencil eraser in the alcohol (making sure that the alcohol content isn't excessive) just dampen the eraser with it! And rub it on the comutator as the motor is running... DO NOT add to much thumb presure here or the motor will get hot, and possibly burn up, but enough to use the alcohol as a polisher an the eraser acts as an abrasive cleaner, and will polish the comutator till its mirror like! Then your ready to run trains! I found this to work the best an hasn't failed me yet! And I do this tune up on my own trains every 6 months! So..... And after the first time I done it. They don't seem to get as cruddy anymore! [ 05. January 2003, 11:39: Message edited by: 7600EM_1 ]
