Re: Sanyo Motor

--- In CAD_CAM_EDM_DRO@y..., "Carol & Jerry Jankura"
<jerry.jankura@s...> wrote:

> Folks:
>
> I've come across some Sanyo stepper motors and wonder if anyone has

torque> specifications for them, or knows where I would look. I
already checked the> Sanyo web site, and their current offerings do
not match this number. I> believe that the motor was originally OEM'd
to IBM. The Sanyo part is:> 103G770-2516

>
> The motor is rated 4.1volts @1.1 amp.
>
> Also, would these motors be suitable for driving a Sherline 4400

lathe and> Sherline 2000 mill?
Carol & Jerry Jankura


Carol and Jerry,

It was good to include the electrical specs, but
we need the physical size of the motor as well.

That, more than anything else; is your best guide
to estimating torque. The same size motor can
be made with an infinite variety of windings;
all of which produce about the same holding-torque;
but differ in driver-requirements, speed capability,
etc..

I doubt that part number means anything. It's almost
certainly an OEM part number; for IBM or whoever.

If it's a typical "IBM printer stepper", it's a
single-stack size-34, with a funky shaft-size <g>,
and a 2-deg step angle. I.e., 180 steps/rev instead
of the more common 200/rev.

And if that's what it is, then it's about 125 oz-in,
give or take 20%.


Note that a higher or lower phase-resistance does
not make a motor more or less 'efficient'. It's
simply a different winding option. A different
tradeoff between performance and driver requirements.

Torque is produced by magnetic force. Magnetic
force is directly proportional to "ampere-turns."

Ampere-turns = the current flowing in the coil,
multiplied by the number of turns around the core.

In other words, you can take a particular
physical motor frame; and wind it with one turn
of huge wire; pump a hundred amps into it; and
you'll have 100 ampere-turns of magnetic force.

Now, take that same exact motor frame, but wind
100 turns of much finer wire on it; and pump
only 1 amp through it. You will get the EXACT
SAME magnetic force, i.e. 100 ampere-turns

Amps X turns = force (torque). It's that simple.

Obviously, the 1-turn winding will be a GREAT
high speed performer; having almost zero
inductance. But finding a 100-amp driver for
it might be a problem...<g>

The 100-turn version will run on any 1-amp
cheapy-chip in your junkbox; but it's not
going to spin very fast.

There are a few second and third order effects
that do cause the holding-torque to vary a bit
between different windings; but the above
ampere-turns rule is 90% of the game.

Hope this helps a bit,

Richard