Ritchey-Chretien
Aperture: 18 inches
Focal length: 189 inches
Focal ratio: f/10.5

Hour Angle/Right Ascension Gearing

Byers 15 inch 359 tooth worm gear and stainless-steel worm

Declination Gearing

Schmidt & Assoc. 5.6 inch, 242 tooth worm gear

On each axis there is a 200 step/rev stepping motor geared to the worm with a 4:1 gear reduction. The stepping motors are driven with a microstepping drive with 10 microsteps per mechanical step. The result is 0.451 arc-seconds per microstep in hour angle, and 0.675 arc-seconds per microstep in declination.