Rocky Plains Observatory

Observatory Information

- Equipment -

Planning Design Construction Equipment


- Permanent Pier

As detailed in the Observatory Design section, I designed and fabricated a large diameter steel pier that is capable of handling just about any mount or scope I can imagine in my observatory.  The base is fabricated of 3/4" steel plate.  I paid to have this 'donut' of material (as well as the top plate) cut from plate using an automated flame cutter.  I machined six radial mounting bolt slots, to allow some rotation of the pier to line it all up (the bolts in the concrete were as accurately orientated as I could make them, but I wanted the ability to tweak in the alignment just incase the adjustments on a mounting were insufficient).  The top plate was sized to handle either an AstroPhysics 1200 mount or a Paramount ME, and I machined the necessary tapped holes for both mountings.

The steel pipe turned out to be the easiest part to locate.  A local salvage yard had a pretty good selection of steel pipe, and I was able to buy a 6 foot length of 12" ID X 3/8" wall pipe.  I considered 14" pipe, but at zenith a long telescope would have been close to the pier, so I went to 12" to buy another inch of clearance.

Though I can weld good enough to stick steel parts together, I was not about to tackle welding up the pier parts (I wanted it to look and work well, plus I did not have the necessary tools to cut the pipe to length).  I found a local fabricator to do the job and to sandblast the finished assembly.  As it turns out, this fellow had recently spent over a year in Hawaii - building (welding) the base structure for the Gemini telescope on Mauna Kea!  Very cool.  Evidently welding at 14,000 feet has some challenges. 

Pier in place, showing below floor mounting details (floor panel removed).
Pier Top Plate, with 1200GTO mount base in place.


- Telescope and Mount

As mentioned elsewhere, I have settled on large refractors for the majority of my backyard viewing.  Constantly dropping temps, and finicky seeing have led me in this direction.  I was fortunate to have been able to locate a used late model Astro Physics 180 EDT.  This scope is delivering consistently fine planetary images, and is ready at a moments use now.  The scope fits pretty well in the 10x12 building, but I'm glad I didn't make the building smaller.  When I started the building, I wasn't expecting to put such a large refractor in place.  Just goes to show, make your observatory as large as you can, your needs can change.

For mounting, I am using an Astro Physics 1200GTO.  After seeing these mounts in action at Astrofest '99, I got on the waiting list, thinking I would eventually be able to make use of one.  At the time, I had a Losmandy GM200, but wanted the Goto feature in my backyard to help me track down light polluted objects.  The GM200 was a great photo platform, but the tangent arm dec wouldn't allow goto.  In hindsight, I think the GM200 might be a little better for such a large refractor, due to the tangent arm, but it was a good tradeoff.  Being able to walk into the building, roll off the roofs, switch on the mount and instantly seek to an object is undeniably  convenient.  So far the mount has operated pretty flawlessly, though sometimes it seems to have a mind of its own when powered up.  For power, I utilized a scrap power supply from a tape autoloader product we produce where I work (Hewlett Packard).  It's nice to finally be off of battery power!

 My Baby, 180EDT on 1200GTO Mount



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