Home Observatory size?

[Kevdan]

Hi all,

After talking to the better half, she has now agreed that I need a purpose built shed for the Scope and stuff, so i pushed that little bit and she now agrees to a roll off roof obsy, So question is what size does it have to be for my kit, Main scope and mount is as in my sig, and will just need storage for the 150p, garden will take up to a absolute maximum size of 9' x 9'

and can anyone reccomend ready built ones.

Kev

[Bizibilder]

For a 250PDS I would say that 8x8 feet would be a minimum. My own shed (in my sig) is nominally 6'6" square and there is just room for me and my scope (200P but normally a 120 refractor). Next decision would be metal or wood? Both have their pro's and cons.

[JamesF]

From your list of kit it looks like you'll be wanting to do some imaging, so you probably want at least somewhere to sit and work, or even a separate "warm" room. In that case I'd go for the full 9'x9' if you can. I really don't think I'd go any narrower than 8'.

James

[LukeSkywatcher]

For a 250PDS I would say that 8x8 feet would be a minimum. My own shed (in my sig) is nominally 6'6" square and there is just room for me and my scope (200P but normally a 120 refractor). Next decision would be metal or wood? Both have their pro's and cons.

I was also going to say for a 250mm scope that i think 8x8 would minimum. Lets not forget the warm room. so 12x12???????????????

[dmahon]

and can anyone reccomend ready built ones.

Alexander's observatories seems to be the one to buy if you want off-the-shelf.

[LukeSkywatcher]

Alexander's observatories seems to be the one to buy if you want off-the-shelf.

Crikey!!!!!!!!!!!

They will build anywhere in Europe?. Prices seem good.......................i've bookmarked this site.

I think i want this: With a small wheelchair ramp installed.

[fatwoul]

Why are all the options square? I always imagined that, with a warm room included, it'd be something like 8x12, and the roll off would roll over the warm room section. Is that not how it works? Forgive my ignorance. I'm a dome type.

[Pete Presland]

i built mine 1.8m x 1.8m which is ok for my 200pds, but it was very tight using my old oo10". the size was purely down to cost of materials and i would have made it bigger if the budget would have allowed.

[Pete Presland]

Why are all the options square? I always imagined that, with a warm room included, it'd be something like 8x12, and the roll off would roll over the warm room section. Is that not how it works? Forgive my ignorance. I'm a dome type.

i agree another 1m on mine would be very helpful

[Carbon Brush]

My shed is 10ft x 8ft. It is based around a standard shed from a local shed builder, with serious mods. At the time I thought it was a good way to do things. But afterwards realised the 'Alexanders' would probably have been a better way to do things. When I added up the shed + mods costs, Alexanders would have been a similar bottom line price. But, my home mods took ages to sort out. Alexanders would have installed in the day.

When planning the build, I thought that 6x6 was OK to rotate a scope and store kit.

Then I thought 6x8 to give space for a desk etc at one end.

Then I thought 10x 8 in case I ever buy a bigger scope, which I did before the build was finished.

Less than 5 years on and the 10x8 is stuffed full of kit. I have wondered about putting a warm room into another (very small) shed alongside. So the advice is, don't build to minimum size!

[Kevdan]

Thanks for the replies, I have now convinced myself that if I put the Obsy in front of my existing shed I could probably go up to 10'x10' so may be able to get a small 3'x10' warm room in there depending on how much swing there is on the scope when it's slewing.

The Alexanders do look very nice but also a bit pricey compared to a local shed company plus mods, I will go and see them to see what they can do with regards to the roof.

Kev.

[astronymonkey]

Id consider some sort of hybrid if you can fit it in the garden.

1. get an 8x8 and put it on runners, wheels , tracks.....
   
2. fit a partition (with its own door down the middle) making two 8x4 areas
   
3. slit the roof along the partition and add a hinge so one half can be folded back onto the other (but with one half remaining fixed)
   
4. fit out one 8x4 space, on the fixed roof side, as a warm room (nice !)
   
5. take the floor out of the other half and cut the outer 8ft wall down the middle to make a barn door configuration.
   
6. Install the scope in the side with no floor
   
7. when in use open the barn door, fold back the roof and push the whole observatory back 4ft away from the scope thus giving it the room you need .
   

This uses the space you have very well as when not being used the scope only needs 8x4 for storage and you only utilise the 12x8 space when the observatory is in use. When not in use the space the observatory is pushed onto can just form part of a patio or similar.

Going even further a 4x6 can be used in the same way. I this configuration the observatory is once again on wheels but with a long narrow hole cut in the floor from the door to the centre of the floor...say 3ft long by 6 inches wide. The scope is mounted on a pier and when in use the shed is once again pushed away with the pier exiting via the long narrow cut and the scope itself exiting via the open door. once pushed back the gap in the floor is covered with a wooden fillet and the shed used as a warm room.

I hope this explains what I mean :confused:

Cheers, Astronymonkey

[Carbon Brush]

Something I didn't get a chance to do before my build.

Go and look at other people's sheds. If they will let you of course.

I only had sight of one example before instructing my local shed company, hence the modification effort involved.

The big problem I found with a shed builder is they are used to building a box. Floor, roof and 4 sides are all fastened together to make a rigid structure. With a scope shed, it has to be rigid without a roof. When you push the roof against a side to open, the side has to remain rigid. Then you probably hope it will last longer then an ordinary shed. The door does not have to be wide enough to get a barrow through, or tall, so aiding wall rigidity. The roof needs far more wood than you first think to avoid sag. A sagging roof won't slide. There are lots of things that the average shed builder is not used to doing. He is probably going to make mistakes.

Alexanders have built all sorts of different scope sheds, so stand a much better chance of getting it right than the local man.

I'm happy to share the rights and wrongs (lots or them) on my build. My standard shed came into the garden at less than 50% of Alexanders price. But this saving was quickly lost in the extensive changes I had to make.

[r3i]

Interesting thread, as I'm also in the early stages of planning an observatory.

Apologies if I'm semi-hijacking the thread but could I ask about the third dimension: Are there any recommendations about the how high the walls of the observatory should be? In the past I think I've come across 1.8m as a recommendation but would like to hear what others have to say. I'm aware of the fold down panel that is often used on the southern side to give a better view of that most popular direction.

[Carbon Brush]

A good question on height from r3i. It had me stratching my head for a while during build.

I don't have the answers, but here are some things I thought about.

A low side means you can see near the horizon.

But do you have fences, buildings, trees in the way?

Also, low views aren't so good for seeing, so (with the exception of south) is a low view important?

High sides provide shelter from wind and stray light.

They also make your shed less obvious to others when open.

Then there is the option of adjusting the pier height (another big subject) if you think the side height is wrong.

Then what scope do you have?

Suppose you own a frac now and sit on a chair.

Next year you might own a newt and be on a step ladder for near zenith.

I keep a plastic caravan step in my shed for this.

Finally, not exactly a height issue, but it can be.

There will be times when you want to try a scope on a nearby object in daytime.

For example trying to focus with a new camera or eyepiece combination.

If (like me) you have an EQ mount + newt, doing this with a level tube is easier.

Can you look through the open door to a distant object?

Does a low side allow you to see something distant?

No answers, sorry. I think the final choices are determined by the location and the individual's preferences.

[Kevdan]

For me And I got a south facing garden low sides cant be any benefit due to the houses built at the back of my garden so anything lower than the roofline is out, But I may be able to gain a little more viewing if I put the shed/obsy onto a raised bed say 12" high which when you add the base of the shed will take it up to probably about 14" and its suprising how much extra you can see from just a little height.

Kev.

[r3i]

Thanks DV for the list of things to consider - I think you're right that there are so many variables resulting from location and equipment that there's not going to be a definitive answer on this.

I'm probably going to first set up my pier, then build decking around it and later on put the observatory on top. So I'm going to defer my choice of wall height until I've had the rig set up after the decking has been done and get a feel for what is going to work best.

[Bizibilder]

There is a limit on how high/tall a "shed" is allowed to be. Also I believe this depends on how close the "shed" is to your boundary. I just Googled this: http://www.planningp...s/outbuildings/

Hope it helps.

PS Read the bit about floor area - Some larger Obsy's / warm rooms may fall foul of the dimensions!

[JamesF]

Sometimes I can really see the attraction of a dome that has an opening which folds down well out of the way and gives plenty of protection from the wind, stray light and so on. Shame they're such a sod to build

There's no reason a roll-off roof can't run on top of fold-down walls as long as they're strong and rigid enough, or that you couldn't have a small fold-down section, say, to have the option of imaging the sun or moon on the horizon. The problem there is security, I guess. You don't want the side of the shed falling out if someone attempts to remove the hinges.

Parts of the walls could be integrated with the roof so they roll off as well, but that could make the roof very heavy.

James

[Carbon Brush]

Good point from Bizbilder about planning.

A small shed in the right place does not require building regulation or planning approval. As it gets larger, or is in proximity to a boundary, or other building it may need one or both.

That is not to say you can't build a 20ft square, 15ft high shed. It's just you have to start using timber that has been treated to be flame retardant, prove structural soundness, make it look nice for the environment, etc.

At the time of my build, I was OK. But the rules do change with time. Today I would think first about the shed I want to do the job properly. Then look at the 'paperwork' situation. Then either go and sort this out, or compomise on the size, etc.

[laser_jock99]

My only advice would be to build to the maximum area your site/wife allows, bearing in mind you need to keep the Southern horizon clearest. Wall height depends upon the scope you intend to use and the height of the pier. In general refractors/SCT's can have higher walls and piers and piers than Newtonians. If you intend to remove the scope(s) after each use then you can have a really high pier that just clears the sliding roof. It does mean you can see down to the horizon though- only usefull if have a suitable site!

Viewing low down objects...