set-up

Equatorial Tracking Platform

I purchased a tracking platform for use with the 20" Obsession because I wanted to eventually do some deep-sky CCD imaging with an SBIG ST-237. I have since sold both the Obsession and the tracking platform, only to buy a larger Obsession (25" f/5) and a larger tracking platform (24 - 25" dual axis aluminum, again from Tom). I have also acquired a Canon EOS 20Da digital SLR that I plan on using instead of the CCD. I've made a second set of truss tubes for the 25" and plan on using the tracking platform for astrophotography sessions. I do have a "Go To" system on the 25" but need the equatorial platform to elimination field rotation issues with Alt/Az tracking. So here's some information on the set-up I used to have:

This tracking platform has turned out to be a great purchase because I've quickly found out that there is a "downside" to having the largest telescope at a star party --- the crowd. Without the tracking platform I was constantly having to re-center the viewing object for each new person (especially at higher magnifications!!!). This platform works great and keeps the object centered for about an hour at a time. The great thing about this platform is that I get very good tracking with very crude polar alignment. Polar aligning involves little more than pointing the platform in the general direction of Polaris.

Now, I love going to our local star parties because I can spend more time exchanging stories and information with people and virtually no time re-adjusting the telescope - even at magnifications greater than 600x. And this is with a 20" Dobsonian!!!

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Here is the platform designed and sold by Tom Osypowski of Equatorial Platforms. This is the dual axis model which has a second drive for altitude adjustment. The top section swivels about the axis located at the narrow end.

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telescope_15a.jpg (34168 bytes)

I use telescoping aluminum ramps to load and unload the telescope from my truck or station wagon. I've found that these ramps work well for mounting the telescope onto the platform. I made a couple of 8" high "step stools" which I use with the ramps as pictured above. Once the ramps are in place I wheel the telescope over the platform and position it over the center pin. I've placed some guide marks on both the telescope base and the platform to help with the positioning over the center pin.

From this point, I remove the wheel assemblies and the ramp system, assemble the telescope by attaching the truss poles and secondary cage, and collimate.

My goal is to get the timing of the total setup process (ready to view) to under 20 minutes. My fastest setup time at a remote site had been 17 minutes.