PDA

View Full Version here: : Height of the dome.

Mekon
18-03-2012, 12:32 PM
Hello All,

Tomorrow I will sign a contract on a new house, while it isn't in a dark sky area, it is a lot darker than where I am now.
To take advantage of this, I plan on building a permanent observatory, using a dome from Sirius or Astrodomes.

As it will be probably three meters from the ground to the base of the dome I will need to get it designed properly with an engineer's or architect's design. The question I am unable to answer is - "How high to put the floor in relation to the base of the dome?" Or to put it a different way, "Should the base of the dome be at my waist height, chest height or something else?" My instinct is to put the base of the dome at the same height as the mount, but I am new at this and don't want to make such a basic error.

Thanks for any help,

Mekon

bojan
18-03-2012, 04:10 PM
Centre of the dome should be at the height where the declination shaft is when in horizontal position.

ChrisM
18-03-2012, 08:42 PM
Paul,

My dome is also 3 metres off the ground, and I put the floor about 750 mm below the bottom of the dome. Other factors that come into the equation could include what type of scope you will have, height of pier, type of mount, and whether you will be doing visual observing or AP.

When my scope is parked horizontally, the dec axis is just a little higher than the lowest part of the dome aperture opening. This means that if I want to look at something on the horizon, I can't see it with the full telescope aperture, but that is not a problem. Anything worthwhile seeing will be at least 30 degrees above the horizion.

You can see a picture of my observing floor in post #12 here:

Of course, having the walls 3 m high then allows enough space for a room downstairs.....

Chris

Barrykgerdes
19-03-2012, 07:46 AM
Hi Paul

I built an observatory using a Sirius 2.4 metre dome 12 years ago using colour bond, timber and the dome.

Unless you need to see the horizon it is not necessary to have the telescope go below 25 degrees. This makes it much easier to handle however placing a 12" SCT on a wedge 2 metres above the ground will present some challenges.

I will attach a zip file of my observatory where you can look at a scaled arrangement of the components.