Author Topic: Fairbanks Morse Generator head  (Read 3195 times)

ZackaryMac

  • Nova Scotia, Canada
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Fairbanks Morse Generator head
« on: January 23, 2007, 02:48:09 AM »
I have inherited a 3kw FM generator head that I detached from a Wisconsin TE engine, and I am having a shaft made up, along with making a bearing support, so I can belt-drive this unit from my Onan RDJA engine.
This generator originally could not only make 120v at 1800rpm, but was wound, with 4 more brushes on the armater, besides the two on slip rings, to be able to start the engine. So the rotor has slip rings and also more brass contacts all around with 4 big brushes, just like in a 12v starter.
The brush assembly is bolted in such a way as to be able to rotate it axially, as though to adjust timing (for some reason).
I believe this unit is c.1950. Big. Heavy. Nice. Probably put out 3000 watts forever.

So, all this info leads to a question: Can I run this unit backwards and still make 120v ok? Mounting it beside the motor will make it a lot more "compact", and keep the weight in-line with the engine, otherwise it will have to be offset to rotate it the same way it was originally turning. I have no intention of using the starting aspect of it, as it probably wouldn't turn the diesel over anyway, beside the fact the diesel has it's own starter . I suspect it can be reverse-rotated, however it would be nice to hear from someone that knows, instead of guessing.
Also, why in the @$#% would I want to rotate the brushes? To time what? Or phase what?

The best part is, I don't know for sure if the unit isn't damaged. It turned the gas engine over, and I had the engine spitting and sputtering on ½ a cylinder enough to move the volt meter some, but couldn't load it.


Final and last question: does ANY of my rambling make any sense? :D I know the wife has a tough time making any sense of me by times...
Kubota EL300A-R 4hp 12v Generator
Kubota B6100 HST Compact Tractor
Onan RDJA 8hp
1994 Chev S10 w/Isuzu C223
All are diesel.

Stan

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Re: Fairbanks Morse Generator head
« Reply #1 on: January 23, 2007, 04:17:45 AM »
Don't be so sure it wouldn't turn over a Lister with the compression release activated.  A simple timer circuit set for 5 seconds could then activate a solenoid to flip off the compression release and the flywheel would turn it past the first compression if it had enough speed.
Stan
btw...if you don't want the gen head, I'd be glad to take it off your hands. ;D