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I bought a old SW1500 to convert into a powered box car. the issue I have is that the motor gets pretty hot after just 2 mins of running. no cars in tow and the decoder and motor are almost to hot to touch? any reason for this?
I'd guess that the motor has some bad brushes. You can buy a set of brushes and springs from Athearn. The armature is also probably dirty and needs to be cleaned up. While you have the motor apart, looks at it carefully to make sure you don't have any broken windings. It would also be a good idea to measure the current being drawn at full slip, as some of the old Athearn motors can draw near a full amp. also, having the motor enclosed in a box car doesn't give the natural heat built up by the motor any place to escape. Drilling a series of holes in the boxcar floor may also help.
I will replace the brushes tonight and give that a try. I figured they would draw more amps being older. I dont know the year of this switcher but it stil has metal side frames. I think the later run had plasic? It might be a 20 year old engine? I run with the box car doors slightly open so that the heat can escape. When I had my P2K S1 converted it was never hot. what if I went with a larger amp decoder? I have all the space I need for one?
If it still has the metal side frames, it is a very old Athearn. I would replace the motor with a newer one if you can. I have 3 SW1200 with the metal side frames and before i re-motored all of them, the engine ran hot even after i replaced the brushes.
The metal side frame switchers were made right up into the 80's before Athearn switched to plastic. Given that, it's at least 20 years old and may be as much as 40 years old. Athearn made incremental improvements to the motors throughout the life of the SW-7. The really old motors had completely open frames with the windings exposed. If you have one like that. you really shouldn't waste any more time on it, since they were always power hogs and tended to run hot. A larger decoder would make no difference. The best thing to do is replace it with a motor used in the last line of BB style RTR units. I think you can still buy these from Athearn. They will drop into the same mounting holes as the older Athearn motor. It will run much better and cooler.
thanks for the info guys I think i will find a newer motor to drop in. I bought a cow/calf set on the bay for $20. My intentions for bothe were to be powered box cars to go in the mix of cars behind my steam engines. I really liked my C&NW S1 so I removed it from box car service. Down at the club on open house nights I would put the powered box cars in the middle of my 70 car train and then watch everyone scratch their heads on how it was pulling so many cars with one engine
I would put the powered box cars in the middle of my 70 car train and then watch everyone scratch their heads on how it was pulling so many cars with one engine
Sorry Willis
No vids of me running with the powered box car but here are a few pics of the new athearn chassi under the BB box car. it still needs to be painted and side frames detailed to look like a hi speed freight truck. I always like the questions I get on how I can pull a 70 car train with one steam engine and the guys running diesels have 4 locos to pull the same if not shorter train.
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