Telescope Mounting and Drives

This is the equatorial head of my telescope mounting. It has been the object of a great deal of work over the 20 years I've had this scope.

The mounting started out as a Star-Liner mount, which was very heavy but quite rough in quality. My first modification was to replace the original RA drive with an 8" Byers drive.

Recently I upgraded the entire mounting by moving the 8" gear to the declination axis, adding a new 9" research-grade (meaning it was lapped) Byers gear to the RA axis, and replacing the bearings in both axes (actually the original dec axis only had sleeve bushings). The bearings were installed in newly-machined, brass collars that were threaded onto the original aluminum castings.

The original 1.75" steel shafts were retained, but the dec shaft was cut off below the drive, and a 1" stainless-steel, threaded extension was added to hold the counterweights.

All the machining was done by a fine local machinist, Karl, who exhibits old-world care and quality in his work.

This is the RA drive assembly. The gear is inside an anodized aluminum housing, with the curved face enclosed by 1/8" Lexan. The altitude adjustment screw that Karl made is visible in this view. There is an azimuth adjustment mechanism as well, but it is on the other side of the mounting, not visible in this photo. However, the ball bearings on which the entire head rides when turning in azimuth are just visible in the space between the head and its base.

This is the beautiful 9" Byers RA drive gear behind its Lexan cover. It has an innovative spring-loaded worm that keeps a settable, constant pressure against the drive gear, resulting in a consistent drive rate with virtually no backlash.

This is the declination drive, which served very well as the RA drive for 20 years until this recent upgrade.

And this is the 8" Byers gear, still beautiful after all these years.

Details about the Tube Assembly and Optics, and Astrophoto Equipment I use with this scope are also available.