A home made 12-1/2" Newtonian on an English yoke mount. First light was June 27, 1990. Pittsburgh, PA.

The mirror was purchased from Galaxy Optics, now defunct. The tube was from Parks Optical. All other components were fashioned from scratch.

For a discussion of the design of the RA drive, see http://theworldofastronomy.blogspot.com/2015/12/calculating-worm-and-worm-gear-factors.html