How Do I Reverse a Repulsion Inductance Motor?

Cool beans!

That's the info I needed. Great diagrams. Thanks a million.

If what is bothering you is the chance you might be cut by a sharp piece of metal dirty with contaminants, it would make sense to disinfect the sharp parts and attempt to attach a temporary barrier to those edges.

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Washing the areas of concern with a volatile disinfectant like any of several types of alcohol... the higher the purity the better, would probably help a lot. Covering any sharp edges with tape of some sort could also make it a little safer.

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The idea of wearing some thin gloves, like surgical latex, comes to mind, but gloves and rotating machinery are generally ill-advised.

What with that nice clear diagram and explanation that Solar Eagle provided, I'm pretty sure he's not at risk of getting even a minor paper cut, but probably best not take any chances.

According to wikipedia, maximum torque is achieved when the brushes are oriented at 45 degrees to the magnetic neutral axis. If that is how it's marked, shifting 90 degrees should give you maximum torque in the opposite direction.

Ref: http://en.wikipedia.org/wiki/Repulsion_motor

Yep, I just tried it, and realized I hadn't given enough information. I spun the brushes around 90° CCW, fired it up, and it ran great . . . CW! Then, in good hillbilly style, I took off my shoes so I could count the brushes . 1 . . 2 . .3 . .4. Yep, that was it, so I backed up to 45° and that baby ran like a top in CCW. Of course, running the brushes backwards after lo, these many years replenished the ozone layer in about two minutes, but it looks like it's running in now.

Thanks a lot.

And once again CR4 saves an "elderly gent", months and months of his life! Onward my friend...enjoy it all while you can!

That's great. Motors are fun to play with. I recall as a child talking my father into helping me build a little universal motor (actually, he did most of the work). It was made out of cut pieces of tin can. It did run, got pretty hot, and, I suspect, helped to rejuvenate the ozone layer.

You can expect tremendous starting torque from this design. Make sure everything is bolted down tightly.

Probably worth a good cleaning and undercut of commutater.

And now the other shoe.

So, a voltage is induced in the armature because it has no connection to the stator. How would I measure that voltage? Or, does that even make sense to ask, since it is (sort of) shorted out by the brushes?

Following the Wiki link given by several posters, I saw that these motors were discontinued in the 50s, maybe 60s. I am impressed at the starting torque of this thing; it far exceeds the starting torque of the 1.5 hp induction motor I have on my table saw. I can see how the weight of these was a problem, but was there another reason to discontinue them?

I would think you could open the circuit at the brushes and put a ac voltmeter there. You might be more interested in putting an ac ammeter in the circuit to measure the current.

Yeah, I guess you're right. The current would be more useful to know. That might even tell me why this beast is so heavy. Thanks.

I suspect that these are not made any more as it cost too much to make them.

Simple induction motors are cheaper to product.

Expensive indeed, once the motor is at about 75% full speed, the brushes must be lifted and the commutator bars shorted as shown: