Re: [CAD_CAM_EDM_DRO] What kind of motor should I use?

The cast rotor bars probably wouldn't stay in their slots at much over 300%
of their rated r.p.m. The 400Hz aircraft instrument motor is actually
designed to operate at 400 Hz, the common frequency used on military and
some "civie" planes. They use 400 Hz because all components can be
substantially smaller (lighter) than those of our 60 Hz world.

P.S. don't try to run the 400Hz at 60Hz...The magnetics won't stand for it!

Ray Heckert

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> Did I read somewhere in this group that "regular 3-phase tool-motors" can

be

> used at higher frequencies [with care] to produce high-RPM spindles?

Seems

> dangerous and dubious. Can an expert "in here" on that comment? The

ONLY

> experience I have with HF motors is with a 95 watt "aircraft instrument
> motor" running on 115 VAC 400 Hz. (which I get from a

self-designed/cobbled

> stationary inverter that "simulates" sine-wave 400 Hz/115 VAC). That is

for

> a PCB drill, and it works just fine (12,000 RPM, not 24,000!!!) But,

took

> some fancy machining to install a collet and larger ABEC-7

spindle-bearing in

> place of original "plain shaft", etc.)
>

> Sincere ignernce, Jan Rowland, old troll