Re: [TCML] Tesla's spinning egg of Columbus

["DC Cox" <resonance@xxxxxxxxxxxx>]

You have to measure the inductive reactance on each of the three phases.

One phase is run as normal.  The other two are shifted, as you guessed, 120
apart each.  Just calculate the capacitance reactance for each of your
inductive reactance measurements, and then solve for the capacitance
required to produce the phase shift.

Each motor winding is different and will require different values.

Select wiring size to match the rated full load amperage of the motor (on
each phase).

That's how I did it with both my 5 HP and 10 HP windings to get a nice
spinning egg.

Egg is hollow steel with a 3/16 inch thick wall.  We machine it up on a
CNC.  Perhaps local shop could do this for you.

Have fun!

D.C. Cox



On Sun, Nov 16, 2008 at 10:28 PM, Jim Mora <wavetuner@xxxxxxxxx> wrote:

> Hi Dc,
> I happen to have a 5HP 3p motor that is not being used for anything. Is the
> phase shift intended to provide semi equidrive @ 120 degrees. Please drop
> me
> more info offline if you prefer. Cap sizing and wiring? I have a number of
> 380volt run caps.
> Jim Mora
>
>
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
> Of DC Cox
> Sent: Saturday, November 15, 2008 9:48 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] Tesla's spinning egg of Columbus
>
> Easy to do with a 5-10 HP 3 phase electric motor winding.  You just shift
> the phase on two of the three windings using capacitors.
>
> Dr. Resonance
>
>
>
>
> On Sat, Nov 15, 2008 at 12:47 AM, Jim Mora <wavetuner@xxxxxxxxx> wrote:
>
> > Very cool. Has anyone wound one of these on a big variac core like a
> 1256d.
> > Perhaps you could share the specifics if you have. I like the simplicity
> of
> > using a clear plate. I have a motor controller that can make 3 phase 240
> > from single phase 240 at about 2.2KW would this be enough to energize the
> > core with this configuration? Where to find a core is the next problem. I
> > have three flawless, complete 1256D's that are not going to be stripped!
> >
> > Thanks,
> > Jim Mora
> >
> > -----Original Message-----
> > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf
> > Of Jason Johnson
> > Sent: Friday, November 14, 2008 8:44 AM
> > To: Tesla Coil Mailing List
> > Subject: [TCML] Tesla's spinning egg of Columbus
> >
> > I know that this topic comes up occasionally on the list, but I just
> > ran across a neat little video of what is basically described in the
> > subject line. Other interesting videos from MIT are to be found here
> > too.
> >
> >
> >
>
> http://techtv.mit.edu/genres/19-engineering/videos/718-physics-demo----magne
> > tic-motor
> >
> > Enjoy.
> >
> > Jason
> > _______________________________________________
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> >
> > _______________________________________________
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