Dobsonian telescope is an excellent observing machine. It features
unmatched stability and smoothness of motion. Plus it is eminently
compact and transportable. However, the Dobsonian has one major
drawback -- no motor drive. You have to push it around to follow
what you're viewing. This can get to be a hassle.
But set a Dobsonian
on an Equatorial Platform and experience INSTANT MOTORIZED TRACKING
-- 75 minutes at a time! Wherever you point you are tracking --
smoothly, precisely -- without losing stability, ease of operation
mounted on an Equatorial Platform becomes the ULTIMATE USER-FRIENDLY
Pictures of Dobs on Platforms were taken at various Star Parties.
A C-11 on a Platform! Here
is what owner, Gail Massey of Goleta, CA has to say about
"I've been using the aluminum dual-axis platform you
built for me for more than two years now. As you may recall
it was originally designed to work with my 10" F/6
Newtonian, which had been mounted on a classic Dobson base.
The equatorial platform was essential in permitting me to
perform imaging with a CCD camera, and I have used it with
my 8" Newtonian as well. Last year it occurred to me
that I could also use the equatorial platform with an 11"
S-C tube assembly if it were held in a Dobson-type altitude
bearing fixture. This turned out to be easy and very successful.
The attached photos show how this is done. On the aluminum
equatorial platform I place the oak Dobsonian azimuth base
I've always used with my Newtonians. The C11 tube is held
inside a new lightweight rectangular adaptor box of 1/4"
plywood fitted with an oak dovetail to grip the dovetail
rail extrusion provided by Celestron on the bottom of the
C11 tube assembly. My adaptor box was made exactly as wide
as the altitude bearing box on my 10" Newtonian. On
opposite vertical sides of the box I attached circular altitude
bearings like the ones on the Newtonian. A small counterweight
was mounted on the lower front of the C11 dovetail rail.
The top panel of the adaptor carries a 9X50 finder scope,
a green laser, and a Rigel Quickfinder sight.
This arrangement is physically easier to set up than a
conventional tripod mount for the Schmidt-Cassegrain, and
the seated position for the observer is comfortable. The
lower inside of the old Dobsonian base provides convenient
storage for eyepieces and other items during an observing
session. Because of the setup convenience and the accuracy
of the platform this instrument now is the one I use most.
I try to observe with it whenever our weather permits."
Klein's 10" Orion Intelliscope on a Compact Platform
Swayze's stunning 16" Dob on its Equatorial Platform. Steve and his
brother, Bruce, put a variety of scopes on this Platform.
Fleming's unusual home built 22" Dob on a Dual-axis Platform
Powers with his fine looking 18" Starmaster on a Compact Platform.
Matthews with his beautiful (and massive) 30" built by Chuck Dethloff.
Corwin has his 350 lb scope on a Dual-axis Aluminum Platform. He has
added a lot of extra "goodies" onto the scope, including an 8" finder,
Sky Commander DSC's (which work very well with Platforms), an eyepiece
rack, a weather station, star charts and more.
homebuilt 22" Dob on a Dual-axis Aluminum Platform; Note how the north
end of the Platform is blocked up to account for the 5 degree latitude
change from Tom's home in northern California. This same Platform
is used effectively from southern CA (RTMC) to the middle of Washington
Miller's fine 20" Dob built by Chuck Dethloff. The scope sits on a
Townsend's 12.5" Portaball
on an Equatorial Platform. Check for Gene's letter on the "Owners
Speak Out" page for his impressions about the Portaball/Platform
Gee and her 15" Obsession
on a Dual-axis Equatorial Platform
12.5" All-aluminum binocular telescope built by Bruce Sayre.
This scope is sitting on a Dual-axis Aluminum Platform.
is an unusual configuration of a 13" Cassegrain optical system
mounted Dobsonian style and sitting on a Dual-axis Aluminum Platform.
The telescope and optics were made by Richard Wessling. The Platform
is on a low stand to bring the eyepiece (mounted on the yellow mirror
box) up to a convenient observing height. Mr. Wessling says, "This
arrangement works really nicely."
Bengier wanted his Compact Platform to match his OTA, so we did a
nice white enamel finish for him. Gary says the Platform "works
Banich's 20" Obsession
on a Dual-axis Platform. Howard made his own Platform from parts
he purchased from us. Great job, Howard!
Heijen in the Netherlands is using a Dual-axis Platform with his 12"
Dob to do celestial sketching. His observing report of first light
with the Platform can be seen here.
James Book of Ottawa, Ontario is
using his 12.5" Obsession with a new Compact Platform. An Obsession
stain and finish was applied to the Platform for a perfect match.
James is using the Platform as a new groundboard for the scope's
rocker box. This keeps the eyepiece height as low as possible.
your big Dob the ability to track the
sky opens up new observing opportunities.
Now it is
a real treat to use HIGHER POWERS. At 500x the Ring Nebula
floats motionless in a velvety black sky - you can really try for
the central star.
PLANETARY OBSERVING takes on new meaning. During moments of
super seeing, details can be fully studied and appreciated (Jupiter's
belts or Saturn's ring system, for instance). There are no interruptions,
no need to re-center a drifting planet. Spend all the time you want
to make a drawing - without having to touch the telescope.
is ASTRO-IMAGING. No problem with an Equatorial Platform:
your Dobsonian is tracking and camera-ready. This important Platform
application is fully treated on our imaging
DRAWING is reaching new levels of excellence and authenticity.
For many observers, recording on paper what they see is a soul-satisfying
activity. Good drawings take time, patience, more time. Here, the
usefulness of an accurate tracking system is obvious.
You like to
share your views at the eyepiece, perhaps bring out the "observer"
in people. I remember one dark night with a group of new viewers
at a star party. We did a fine tour of the September sky. Bright
Globulars, Ring and Dumbell Nebulae, the Andromeda Galaxy. Then
STEPHAN'S QUINTET. I put in 250x and for the next hour those
five faint galaxies hung in the center of the field like tiny ghosts.
Everyone had a chance to really see them, to come to terms with
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