A large part of the motivation to move to a 4.5 acre site near Bourbon, Missouri was to create and have my personal observatory in my back yard for convenient access. Darker skies will help, too. I am planning a roll off building to house my 14-in Celestron SCT. As it will only be used with a CCD camera attached, the building will be just big enough to cover the telescope and computer system. It will be a ongoing project that I will chronicle here as progress is made. Stay tuned.
The first challenge was to locate the observatory. I chose a spot on the South side of my equipment shed to be close to electricity and to get shaded from a dusk-to-dawn light in my neighbor's yard. There are two distant D2D lights to the South that I may persuade the owner to shield but I plan to put up a privacy fence as a safeguard. My horizon will always be higher than about 20 degrees.
The first step is to locate and build a pier to support the GEM mount for the telescope. A concrete pier is easily constructed and quite affordable. The pictures below tell the story quite well.
| | | | A hole was dug and a 12-in diameter Sonotube form was placed over it. The Sonotube was plumbed and braces installed to hold it in place.
The hole is about 18-inches deep as I don't worry much about frost heaving. I can always re-align with the pole if needed. | Four 80-lb bags of Quikcrete were hand mixed to fill the form. | The form filled and the top leveled. |
| | | | | The base for the GEM needs three 3/8-in studs to attach to the pier. I used 10-in lengths of threaded rod which were held in place by the plywood disks. | The threaded rods were oriented to have a "pretty close" N-S alignment. The mount is adjustable for fine alignment. | With the plywood jigs removed the pier is ready for the GEM mount. |
| | The test fit of the telescope mount is rock-solid. The GPS in my Android phone gives the location as
+38 deg 08.045 min
-91 deg 16.178 min
+/- 13 ft
Elev 1000 ft |
The next steps involve building a track system to allow the telescope shelter to move off and expose the telescope to the entire sky.
| | | | | Two rails are used, each consisting of two 2x4s on edge. Chamfers were cut so that a V-shaped groove could center a 1/2" PVC pipe. A total of 16 feet was chosen for the rails. | The rails were mounted on 4x4 posts (2 ft long) that were sunk into the ground. | Dry mix concrete was used to set the posts. No need to mix with water, soil moisture will soon cause the cement to set. |
| | | The rail system is complete (still missing the PVC pipe, though). A floor has been added. The size of the floor is 3 ft x 4 ft - ample to store the 14-inch telescope. |
The next step is to build the movable superstructure.
| | | | | A simple 2x4 frame was built. Note the grooved casters (from Grainger) and the PVC pipes on which they roll. | The almost-finished shelter. It rolls off to the East but does not obscure the Eastern horizon any more than that distant tree line (about 25 deg). Sheet siding and a corrugated plastic roofing called Ondura provide the outer covering. | The telescope is a tight, but comfortable, fit inside the shelter (here shown with the gas grill cover used a supplemental protection. |
The, more-or-less, completed observatory
| | | Note the grass and rock that has replaced the mud from the previous images! Much more pleasant. Note the computer beneath the "table" that serves as a dew protector for the computer and other electronics. The computer is accessed via wi-fi by another computer in the house - no more frozen feet nor mosquito bites! Data acquisition on an extensive list of variable stars is scripted with several hundred measurements possible on a clear night. |
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