Re: weird DC motor

Dale,

A motor with two sets of high current (16 gage wire) brushes
running on two separate commutators is new to me. Multiple
sets of brushes running on one commutator is common for
high quality servo motors designed for low torque ripple.
Many servo setups have a motor and tach on a common shaft
with two separate sets of everything including brushes, but
the tach brushes and wiring are typically much smaller.

The nameplate data seems out of porportion with the rest
of the description. The current seems low for the size
of the motor and the size of the wires.

Oh, I did just remember one type of setup with a set of
dual commutators.... a co-wound DC motor-generator like
the type once used to generate the high voltage for tube
type radios in mobile equipment. Not likely related to your
stuff because they were still different size brushes on
the two ends and because your motors seem to have tachs
or encoders on them.

Feel free to e-mail or post additional info, I love a
mystery!

Regards,
Steve Stallings

--- In CAD_CAM_EDM_DRO@y..., "Dale Smith" <mediasmith@m...> wrote:
> Steve, et. al.
>
> Now that you have made the fatal error of showing some knowledge of
DC
> motors my next victim is obvious.
>
> Some time back, I also made the error of thinking a DC motor is a
DC motor,
> is a DC motor...... and bought three big ones. They are about 5
inch dia x
> 11 inches long with 5/8 shafts out each end. One bare back end, one
looks
> like it has an encoder and one has something else (only 2 wires)
Square
> flange mount.
>
> The things have a pair of brushes on each end. Each pair of brushes
is
> serviced by 2 wires approx 16 gage.
> The data plate says 220 VDC .4 A (400MA) 2200 RPM
>
> 12VDC will run the motors through either set of brushes alone.
>
> 12 VDC willl run the motors much faster if the brushes are
connected in
> series.
>
> 12 VDC will make the motor jump up and down if you wire the brushes
in
> series the wrong way.
>
> They produce a lot of voltage when turned by hand.
>
> Photos and additional info cheerfully furnished if it will assist
in solving
> the eternal question "Whatthehell did I buy and how do I use it?)
>
> WDSmith
>