"Jim Wilkins" wrote in message ...
"PrecisionmachinisT" wrote in
message news:mt6dnXWHRoUmvkHMnZ2dnUVZ_gednZ2d@scnresearch. com...

"Jim Wilkins" wrote in message
...

I think I know every scrap dealer for at least 100 miles, and
haven't seen any inexpensive 3 phase motors in 20 years of looking.
jsw

Craigslist.

It's only a theoretical question anyway, as I put single phase TEFC
motors on my lathe and surface grinder and the mill already had one.

I was wondering if the pedestal grinder, an incomplete drill bit
sharpener, could be its own simple rotary converter since it could be
jump-started with a drill.


Probably the most simple rotary converter design uses no switches, is self-starting, and consists of nothing but a single oil cap and a three phase motor.

Connection and operation is pretty much the same as what is commonly known as a "PSC" motor.

I've stumbled across schematics etc. for such an arrangement numerous times in the past, but I've never built or witnessed one in operation and so I can't really comment further except to say that I suspect it would probably start up slowly and / or tend to run somewhat on the warm side.