Re: [CAD_CAM_EDM_DRO] Re: High speed spindle chuck

Wally K wrote:

> Jon Elson wrote:
>
> The air bearing, integral motor-spindle
> > weighs about 6 Lbs., so a fast stroke is pretty easily achieved.
> The disadvantage
> > to air turbine spindles is that the speed is not constant under
> load, unless
> > thay have a governor on them, which the most expensive ones do,
> indeed,
> > have. Mine has a 3 phase induction motor, but needs high frequency
> power.
> >
> > Jon
>
> Wally K. replys
>
> I got lost when you mentioned the hi freq 3 phase ind motor. Are you
> saying that this motor somehow regulates your spindle speed on your
> high speed air powered drilling motor.

No, some Westwind and other spindles are air powered, some are
driven by an integral AC motor. Mine are of the AC motor variety.
They use air for flying the air bearings, then the spent air is used
to cool the rotor and stator components of the motor. (This is the
smallest 1 Hp motor you are likely to ever see!) The motor itself
is about 1" diameter and 3" long, the entire spindle assembly is
about 2" diameter and 5" long.

The advantage of the AC motor, I believe, is that it can produce
appreciable power over a much larger speed range than an air
turbine. So, if you will be drilling holes over a wide range of sizes,
the AC motor is better. I have seen several shops where they have
3 air-turbine spindle motors that they swap out depending on the
hole sizes (and speeds) needed.

Jon