The Hut is now ready for use! Some cosmetic issues remain. Siding on the sides of the roof, painting etc, but the roof works and there is power. Now equipment can be assembled.
Progress is finally being made on the TSH (Talavera Space Hut). I decided for my location here to go with a sliding roof structure. I also thought about a clamshell type dome. My wife wanted something that would match the house! So there you go. The shed won out! I will do a clamshell when I set up at my dark sky site. The shed design is small, only 8′ square which is big enough for what I will need. Remember though from the last post, you are going to be limited with respect to how low the walls can be. In ths case it turns out that 68″ was a reasonable height. This will allow access to sky down to about 25 degrees to the South, West and North. East we will be a little more obstructed from the roof peak. I am having the builder make the roof as flat as possible. Remember not to forget about the roof peak obstruction! I put the roof on the east side because that is where the house will be and I don’t lose any sky there.
The floor is cement which is about 8 inches deep and is separated from the central pier by 1″ thick foam which you can’t see. The pier is a 12″ diameter cement base which goes about 3-4 feet into the ground, so much deeper than the surrounding floor. 4 j bolts are cemented into the pier base. I have a steel pier for the mount which has slots to accomodate the J bolts. It is very important to be sure the J bolts are oriented properly so the mount is able to point directly to the celestial pole! This will be different for different systems but you will have to do some templating of some kind. Do the templating off of the North Star and do not use a compass! I made that mistake the first time. I lucked out because I was able to adjust the pier using the slots at the bottom and also the mount has some reasonable flexibility with azimuth adjustment.
The question often comes up from people what to go with when it comes to a permanent set up. I had a dome back east. I enjoyed it and it was an excellent shelter for my long focus newtonian but if I had to do it over I probably would have chosen a roll off roof structure for there. Here is my list of pluses and minuses for each design:
Pluses: Excellent wind protection and shields ambient light
Walls are usually low so you will be able to view down to the horizon
Much more room for your equipment since the dome height allows for more flexibility with scope position and size
Minuses: Usually more expensive
Unless you have a clamshell type design you aren’t going to see much of the sky if you are interested in being out there
If you are an imager, you are going to go crazy if you don’t have dome automation since you will HAVE to go out there periodically to manually move the aperture anywhere from every hour to every few hours depending on what you are imaging. Dome automation is very costly! It is also very challenging to get it to work properly.
2) Roll-off roof.
Pluses: Generally easier to build and operate. Also often less expensive
No issues with imaging unattended once the roof is open. No need for expensive software and other components. Opening a roof remotely if desired is cheaper and easier than opening a dome
Minuses: You won’t get the wind protection like you can with a dome.
You might have to sacrifice some horizon sky since this design will have more limitations on how the scope can be parked in order to get the roof to close. If you are operating remotely and you don’t want to worry about your scope position when the roof closes, your walls are going to have to be pretty high relative to your scope/mount. You can lower the walls and park your scope flat but you really can’t rely on software to close your roof safely so you will have to be much more careful there. For example you can use cameras to visually confirm proper parking and then close the roof.
Next up, TSH roll-off observatory progress report!