The short answer:   Nope.

The Long answer - what you need to do is NOT to filter the signal to your
stepper motor, but use microstepping.  The best place to look for this info
is

  Jones on Stepper Motors       http://www.cs.uiowa.edu/~jones/step/

This is a complete treatise on the subject of stepper motors and
microstepping.  There are a lot of others.

I am involved in a project now using stepper motors to control a pan system
for video cameras.  Same issue - at slow speeds they are jerky.  I am
looking into microstepping the camera motor to eliminate the jerking motion.





-----Original Message-----
From: Chris Eddy <ceddy@NB.NET>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Monday, August 16, 1999 5:37 PM
Subject: Need a smooth needle motion!


Comrades;

I have a project with a stepper controlled needle indicator.  I have a
simple 8 bit input.  I have a maximum needle speed.  The problem is that I
have a jerky needle motion.  I have an IIR filter in the software, and you
can see the needle jerk in chunks that resemble binary distances.  (IE the
needle surges less and less as it homes in).  I need good snappy response,
but I need the needle to move smoothly.  Are there any filter gurus out
there that can identify my problem?

Thanks
Chris Eddy
Pioneer Microsystems, Inc.