Update - as of April 2, 2005, the scope is back in the dome and is
operational! We need to install fans and work on some minor
issues.
This page chronicles the testing, discussion, decision-making, and
progress on the 16.25" CUAS club Cassegrain. This telescope was first placed in the newly completed CUAS observatory
in 1992. The story of
the observatory is told here, as written some time ago by Dave Leake.
Here are links to documentation of the various phases of the project:
A view of the 16.25" CUAS Cassegrain (old version) telescope in the
dome is seen at right, prior to
disassembly and reworking. The scope sits on a large wooden fork mount, attached to a large metal
polar shaft.
For years members have had issues with both the optical quality of the
telescope and the unique characteristics of the equatorial mount that
it's place on. Some years ago the original secondary mirror was
removed and replaced with another on loan from CUAS member Aart
Olsen. The whereabouts of the original secondary are unknown.
After making 12 paraboloidal Newtonian primary mirrors, I decided it
was time to make a different type of telescope, and a classical
Cassegrain design was appealing and sounded challenging. So,
following discussion of the various problems of the telescope during a
club meeting, I volunteered to test the optics, and refigure them if
necessary. A couple meetings
later I presented possible designs and made recommendations, which the
club voted to accept. I also decided to make a Cassegrain
secondary
of my own in parallel with the club secondary, for my own 12.5" F/12.5
Cassegrain. (I already had refigured the primary.)
Since the optics are done now (recoated by L&L Optical Services), the
last phase is to prepare the
telescope for them. We need ventilation fans to cool the primary
mirror and some work needs to be done on the telescope mount,
particularly the declination bearings, which are "sticky" in operation,
and make small movements frustrating at best. This is mainly due
to wear and dirt accumulation over the years. New declination
bearings are being made, and fans will be installed. The tube is
getting a fresh coat of paint, and numerous modifications have been
made to the mirror cell. A new focuser was ordered from MoonLite.
A view of the 16.25" CUAS Cassegrain (old version) telescope in the
dome is seen at right, prior to
disassembly and reworking. The scope sits on a large wooden fork mount, attached to a large metal
polar shaft.