Re: [CAD_CAM_EDM_DRO] Re: Running Torque for Slo Syn M062-FD03

> Grant: RUNNING torque for a STEPPER is always LESS than the holding torque,
> and varies WILDLY as speed (stepping-rate) varies. There are GRAPHS of this
> for EACH motor in S.E. stepper motor catalogs.

It's all about inductance, and need to for the drive to supply a
voltage sufficient to overcome the reactive voltage that results from
the inductance as the stepping speed increases.

The graph is only valid if you use a driver very similar to the one
used to produce it. A high voltage chopping driver with a supply many
times the rated winding voltage will run much faster before torque
falloff becomes serious than a lower voltage chopper, which will in
turn be better than most L/R drivers and much better than a simple
circuit which merely sequences rated winding voltage in a steppping
pattern.

The graphs I have seen show curves for each motor with a variety of
moderate to high performance drives from the motor manufacturer - they
want to make their motors look good, and they want to sell the most
expensive drive in their line, too.

Chris

-------------------------------------------------
Christopher C. Stratton
Engineer, Instrument Maker, and Horn Player
ccs@... 617 628 1062
http://web.mit.edu/~stratton/www/brassbuild.html