found this by accident looky looky
Posted 11 February 2011 - 11:20 AM
Wish I could see the full PDF drawings - kinda hard to appreciate it this way!
Posted 11 February 2011 - 11:28 AM
Posted 11 February 2011 - 12:22 PM
the above patent looks like an astrotrack, but is really a barndoor. well the astrotrac is a finely-made barndoor with a microprocessor-controlled motor drive.
funny because even in 1977 you could get a cpu to drive a stepper motor and it was cheap.