hi, can anyone help on how to construct a 8x6 or 8x7 roll off roof observatory with an A roof. does anyone know where their is very good instruction plans on the net? or has anyone here built one already that can help out? i have to get my gear out of my house or i will be shot! whatever you do "dont mention the war"

mind you it's not the time of year weather wise for this type work but i will have to start something in the mid spring months.

wet skies tonight!
james.

Hi James,

I can't help directly with your roll off roof, but its a very common method of converting a wooden shed into an observatory, so there must be plenty of info out there. The apex roof structure would need to be beefed up to maintain its structural integrity, then channels for the rollers, and a frame to support the roof when rolled back etc. My approach was much simpler, I attached a scoperoller to the tripod and I wheel the scope out to my observing deck (my shed has a double door) I have registration bolts which gets me more or less polar aligned immediately. If I'm taking pics, I can tweek the polar alignment in 2 or 3 mins and I'm good to go. The inside of the shed has my computers sheltered from dew, which is where I sit when imaging, more comfortable than a sliding roof design which you are exposed to the elements imo. Setup time is as fast as any "proper observatory" design, cost is much less, and very little work req', and my 10x8 shed doesn't shout "Expensive Observatory".

World famous imager Robert Gendler uses this setup, which gave me the idea to try it, mind you, I'll never be able to take pics like he does

David.

Hi James,

We are building our Roll-Off Roof Observatory. We got the Sky Shed plans on CD, and found them very useful.

We modified bits here and there, i.e. making the foundations hurricane proof!

See: Sky Shed website

hope it works out,

John

Hi James,

My own observatory is built loosely around the skyshed plans which John mentions. It really is a good design. The key is to get a concrete pier in place. I used an 8" length of 14" wavin pipe sink 4" into the ground and filled with mass concrete (God help anyone who has to ever get rid of it!). Mine is also scratch built rather than modifying an existing building. I would be wary of modifying a 'barna shed' as the examples I've seen seem to quite flimsy, But I suppose you could line with ply. However the roof support needs to be incredibly beefy to stop it flexing and sticking. Don't underestimate just how beefy this needs to be.

From experimenting with various mechanisms, I found that by far the best rolling mechanism is to use rail and rollers which are designed for gates on apartment complexes. You can get this stuff from castormart in Dublin. It is expensive (IIRC cost me €250 for everything) but it is the business. I can now open my roof literally with one finger.

If you can't stretch to building with the structural soundness required for a roll off, consider an arrangement where the whole building rolls. You lose the wind protection you get from having four walls but it is an easier build.

You can see some photos of mine here;
www.webtreatz.com/index.php/tutorials/35...4-raheny-observatory


HTH
Dave.

thanks for all the help david, john, dave,

i for sure have to make a very solid design as over here in the northwest it can get pretty wild! where i will be constructing the shed it will be right beside a large building shaded in order to protect it from storms! where the shed will be their is a very good view of the sky from northeast right to southwest. the sky sheds might be the rute to take! it will be about a 6x8 or so size, enough for me and my scopes. i must see if i can get a plan from sky sheds now and plan for the spring. will update you all!

p.s. great website Dave! fantasitic setup! your building sure is secure!

James.

Make it as big as budget and space allows. Remember to leave room for the computer bench etc. Mine's 10x8 and sometimes I wish it were a bit bigger.

I came across 'Building a Roll-Off Roof Observatory: A Complete Guide for Design and Construction' by John Hicks (ISBN-13: 978-0387766034) the other day.

It would be worth getting out of the library, but possibly not worth the £25 that it's going for on Amazon at the moment. It's US centric and isn't as detailed as you would expect from the books title. That said it does give you plenty to think about. Especially when compared to the sky shed plans; e.g. what are the pros and cons of a poured concrete base.

One question though for the people who have built observatories. What, roughly, was the raw materials cost? I know some of you have concrete bases, different roof styles etc. I'm just looking for an idea of how much the wood for the project would cost in a builders suppliers to put a budget for this together.

Hi,

Yes, John Hicks book gives some good ideas, but his plans are for a larger than average size.

Albert, the cost would depend on the size. Mine is 10'x8' (about 3 x 2.4 m) and my budget is about a couple of thousand euro.
I used Sonotube concrete fondations for the building itself. You will also need to factor in tools including electric saws.
The telescope pier will be extra.

John

Al keep in mind that what follows was in 2006.

I cant remember exactly how I can up with the figure but my memory is that it cost me €1200

Timber cost ~€600 about another €400 for the other bits and pieces and I guess the other €200 was cement. The cost of the timber could be brought down by using ply instead of solid planks for cladding. However subsequently I spent 250 on the new roller mechanism which was worth every penny. I guess over time I've added bits and bobs, i.e. security cameras etc but thats something that happens over time. The big shock is the upfront cost of the timber and ancilliaries.

Hi James,
I was wondering how you were getting on with your plans. I am in the planning stage myself. I was looking for a suitable garden shed to convert and I think I found one. I think a flat roof would be easier to roll off. have a look at my site www.imageorion.com/observatory Any comments and ideas for improvements would be useful and welcome.

John

Hi

I am late to this subject as only recently found the web site when trying to get information about roll off roof type and telescope dolly. Like you I aim to observe in the far NW Donegal. As you say the storm issue is very real.
I have built a 1.5 story hut of twin skin breeze block which I can finish with a pier up to the second floor built upon a 600mm diameter x300mm high pier base on top of a re-enforced floor as the structure was build on bog excavated down to rock. This would allow me great standing shelter with walls at 1.85m with a roll of roof opening. I appreciate the need to manage any potential water ingress but my main concern is being absolutely sure that when closed it would not lift off in the frequent severe storms. Even inside my house you are worried when the gusts gust. I reckon a series of toggle bolts or turn buckle type bolts would manage this problem. The roll off would be over steel tracks screwed or welded down onto 8cm box steel section running horizontally on the walls and being supported when rolled off by the box steel supported by steel verticals. As the horizontal box steel sits at around 3.5-4m off the ground I needed a maintenance free option. Wood might not be that durable and as the cost of tracks, rollers and box steel would come in around 1000euro I am stuck with considering a telescope dolly which might with import tax, carriage and cost one in at around 800euro but with a fixed roof there is less fear about losing a mobile roof even with toggle bolted.
What did you finally settle on?
Even though the hut is build and has two floors you could always find some othe use for the second floor area.

Regards

Seamas