Re: ATM vibrations...

[Frank Henriquez <frank@ucla.edu>]

Jan,
  When I upgraded the UCLA 24" telescope to stepper motor drive, I had an 
annoying resonance at the tracking stepping rate, even though I was using a 
microstepping drive.
I fixed the problem by placing the stepper motor on a rubber vibration 
isolation mount (dirt cheap from McMaster-Carr) and addied a better 
flexible coupler between the stepper motor and the gear reducer. Any 
vibration - if present - is below a CCD pixel in width, about 0.5 arcsecs.

Frank
--
Frank Henriquez  Programmer/Analyst  Jules Stein Eye Institute, UCLA
frank@ucla.edu   http://www.bol.ucla.edu/~frank/index.htm