Adjusting the 3rd brush

wardkew

Member
OK, I've read Les' book and searched all the threads, and still don't understand how to raise the brush. I can get hold of it with my fingers and move it 1/8 inch or so horizontally, but can't get any vertical movement.

I was reading about 8 amps during daytime at normal driving conditions. Then I added engine pans and now read 12-14 amps, which I need to cut back, but can't figure out how.

Thanks
 
The best way I have found is with a Chinese chop stick. Remove the band that covers the brushes, next run the engine at a high idle, and with the stick the third brush will slide clockwise and counter clockwise. check the amp meter after a little movement and see what it reads. Never use a metal screw driver as it could short out to ground. * amps for daytime driving sounds high. I would think 3 or 4 would be fine. I use an electronic voltage regulator on my cars and it dose a great job.
 
Using a chop stick or piece of 1/4" or so wooden dowel works well. You might find that it may move better if you use a small hammer or such and give little taps to the end of the dowel rod to help it along.
Dave
 
If adjusting charging rate on powerhouse gen,loosen field brush holder lock screw & move brushup or down to vary rate of charge.If later gen,move field brush up or down with a piece of wood.
 
I've got an old, unrestored '31 generator that still puts out good voltage, but I just move the third brush with my fingers when the engine is off. You don't need to lift the brush from the commutator, just push it up or down a bit for the voltage adjustment. If it 'aint enough, by checking the ammeter when you drive, move it a bit more when you stop next time. One kind of gets to know where the brush goes by experience.
 
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Even on the lowest setting my powerhouse was putting out too many amps, so I make an electronic voltage regulator to fit under the cover and remove the adjustable brush. These pictures show an EVR installed on a 5 brush powerhouse which I haven't restored yet. It's mounted on the generator test stand I made.

On the common long generator, if it hasn't been taken apart to be restored, or at least cleaned, then the adjustable may be stuck pretty tight. With the engine off you should be able to pry on the steel post for the adjustable brush to move it. Up (clockwise as viewed from the rear) will lower the amps output.
 
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