Treadmill Motors (Was 1500t secondary myth)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dave Halliday" <dh@xxxxxxxxxxxxxx>

Quick heads up -- when I saw this email, I ordered four of them.
Considering the 14-pound per shipping weight, I chose the cheapest UPS
shipping option.

The package arrived today (10 days) -- very excellent build quality!
Very heavy and solid, the one unit I tried runs smoothly (this is on 110
out of a variac through  bridge rectifier and a smallish electrolytic
(what I had on hand).  It looks like it expects to have fan cooling so
if you choose not to use the screw-on fan/pulley (I'm not), use a muffin
fan to force some nice cool air though the housing.

The motor has no real way of mounting, I'm guessing that the round body
was held in some kind of clamping arrangement.  I'll be using a
fly-cutter in my drill press to cut out two pieces of phenolic for this.

Also, it was packaged pretty well - 8 out of 10 - the motors were not
individually wrapped but they were well secured and there was a good 2"
of packing material around every dimension.  They have about 3,400
left...

> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Monday, December 06, 2004 7:40 PM
> To: tesla@xxxxxxxxxx
> Subject: Re: The 1500t secondary myth (long)
>
>
> Original poster: <dgoodfellow@xxxxxxxxxxxxxx>
>
> Steve,
>     Surplus center has a 2 hp treadmill type motor for a
> reasonable 9.99
> You could spend more than that on gas driving around looking
> for a tossed
> treadmil on the street!!
> www.surpluscenter.com
>
> item 10-2167
>
> http://www.surpluscenter.com/item.asp?UID=2004120621270779&cat
> name=&qty=1&item=10-2167
>
> they have enough for us all!!
>
>
> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Monday, December 06, 2004 9:34 PM
> Subject: Re: The 1500t secondary myth (long)
>
>
> >Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>
> >
> >D. C.,
> >
> >I am getting tired of the loud gear growling from my angle
> grinder powered
> >ASRG, and have been thinking of going the treadmill motor
> route.  What are
> >your surplus sources for these motors?  Are the motor
> bearings good enough
> >(e.g. very little axial motion) to mount the rotor directly
> on the motor
> >shaft?
> >Thanks,
> >--Steve Y.
> >
> >----- Original Message -----
> >From: "Tesla list" <tesla@xxxxxxxxxx>
> >To: <tesla@xxxxxxxxxx>
> >Sent: Monday, December 06, 2004 11:41 AM
> >Subject: Re: The 1500t secondary myth (long)
> >
> >
> > > Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>
> > >
> > >
> > >
> > >
> > > One "tunes" a sparkgap by adjusting the dwell time.  This
> is usually
> > > done by using a DC motor for the drive and then adjusting
> it's speed
> > > with a small variac/rectifier/cap combination.  We use a lot of
> > > the "tredmill" type motors available surplus.  We use
> 3,000 rpm motors
> > > with a 1-2 HP rating.  We usually mount the spark gap
> rotor in a pillow
> > > block configuration so we can change pulley sizes to
> adjust the rotor
> > > speed in a range that is most effective.
> > >
> > > You can also put a spark on both sides of the rotor and
> connect them in
> > > series.  This is usually done at power levels above 7.5
> kVA to provide
> > > additional quenching.  You can also experiment with using
> one side of
> > > rotor (dual gap) or both sides of rotor (quad gap) to see
> the effect of
> > > quenching on your system.  Use a dual gap if possible at
> lower power
> > > levels so you don't end up wasting all your energy in the
> form of heat
> > > and light in the sparkgap.
> > >
> > > Dr. Resonance
> >
> >
>
>
>
>
>