What size obsey

[Robfal]

I currently after advice at the mo! I'm planing to build an observatory at the bottom of the garden (now got the power + Network there --- 50m run!!) but want to make it as in-intrusive as possible. I shall part bury it into a bank (to the north) however I'm still undecided on size

My original thought was to build a 7x7 (2100 x 2100) obsey with an attached 4' (1200mm) extension to act as a warm room, however I'm now wondering whether that might be too big and whether I could get away with a 6x6 observatory (+ mini Warm room).

I've currently got a ed80 on a EQ6 (which I would put onto a pier) however I do have my eye on one of those new Explorer 200 DS reflectors that Steve has just got in. What would be the minimum sensible size? What about height of shed and/or pier height?

Cheers

Rob

[RobH]

Don't make the mistake of building too small.

Scopes on EQ mounts can occupy a remarkable amount of room, and you may want to expand in the future too.

I have a 6 inch F8 refractor in a 9'3 x 9'6 observatory, and I have to be pretty careful to make sure I don't bump into it.

I'd say 8x8 for the scope room, and for your warm room, by the time you have a desk in there, 4 ft will be very tight.

Cheers

Rob

[barkis]

Rob's so right. When I built mine,I settled on 7'x6', with an option to add a warm room later. Not long after I finished the Obs., it was apparent I should have made it bigger. However, when I started to add the warm Room extension, which eventually became a second Obs., I utilized the extra foot available to both buildings. It meant I had my garage wall as part of both, but the extra space is brilliant.

Don't skimp on the size, you won't regret it.

The pic. shows what I mean. The section on the left gave an extra foot.

Ron.

[Bizibilder]

I've built mine 6x6 from a shed (which is less than 6x6 inside - an antitardis!!) and have a soon to be pier mounted SW200P on an EQ5. There is just room for me and the scope but it is a tight fit. The tripod is a no-no in that space as the legs get well and truly in the way - the pier was always my intention anyway and that should help.

As to height - you will have to decide that as there are many things to consider such as: Low enough to see to the horizon - if you have one. High enough to block neighbours / street lights - if you have them etc. etc. You will also have to match the pier height to the wall height - to suit your particular site. Additionally you need to be able to get to the eyepiece at least reasonably comfortably - you have a refractor on a largish mount so a taller pier is probably in order. The whole thing is a compromise!!

When considering my own build I spent a LOT of time drawing out my site in detail and measuring angles of fence heights and neighbours house roof lines etc (a crude protractor and sighting stick is all you need) eventually settling on the best compromise (Which was, in accordance with the appropriate law, in the original place that I had thought of!)

Hope this helps.

[JAO]

My 2p worth is look at the space you have to build in, think about the kit you are realistically aspiring too and build the biggest you can afford without upsetting the neighbours, the familiy or the buiding inspector!

There are plenty of tales of excellent observatory builds where 2 years on the comment is "if only I hade built it a little bigger!"

Adrian

[Merlin66]

Rough rule of thumb: the inside width should be twice the focal length of the scope ( assuming a GEM and a newtonian scope)

I have a 12" Lx200 on a wedge/ HD tripod in a 6' x 8' which I'd have to say is a minimum size!