Is this a crazy/stupid idea?

[upahill]

Hi All,

I am a complete newbie, but whilst waiting for First Light with my new telescope I have been reading through some of the threads on here about DIY observatories. I have quite a big barn which I could build one in, ready to move the garden so I was thinking about different designs which would look good, and also be easy to produce in a kit-form for anyone else who wanted one.

Anyway I came up with this so far..

I think for my own use I would want it to have a diameter of approximately 2.5m and have a decagon wall around 1m high. The idea being that the panels are all constructed in a modular fashion that can be bolted together in a hour or two max. Each panel would be PVC outside, bonded to a 50mm Celotex or similar insulation with a wooden (or maybe ABS) framework. So the whole structure wouldnt weigh very much.

The central hexagon (shown as missing) would lift up using some form of linear actuators meaning it could be opened and closed electronically via a remote, the section of wall underneather would obviously be a door.

The next challenge would be to make it rotate on its supporting wall. Which I would probably do using a steel circle mounted on the wall with a track that the decagon roof would 'click' into. This could then probably be motorised/automated somehow.

Anyway, at the moment its idea stages, but I need a new project to sink my teeth into and keep me busy on cloudy evenings.

Thoughs appreciated.

Sam

[barkis]

From that Image, I have to wonder how your telescope would have access to the zenith.

Rotating it would also seem to present a problem design wise.

Of course it could be modified to rectify both difficulties.

It would seem to me to be easier and more convenient, to make a hemispherical domed enclosure.

Fibre glass being the material of choice perhaps.

Ron.

[Stargazer33]

Hi Sam,

It looks/sounds a very good idea. I think I have seen something similar to your prefab sections on the web already, but I can't remember where!

Obviously the track would have to be cut where the door goes and the door with its section of track would need to be able to support the dome without dropping. Unless you are intending on having a 4'-6' high supporting wall.

I like the bolt together idea as you could assemble the dome in two or even three parts; lift them into place and then do the final join, rather than trying to lift the whole dome in one piece. The smaller pieces would obviously make delivery much easier if you intended to go into production.

[upahill]

Yeah was thinking about the zenith, only real way to do it still using a geosphere is to have many more faces...

Will have to look into the construction method of a fibreglass done. Or how to construct a mould.

[skybadger]

I wouldrun the track around the inside lip of the geodesic to solve the rotation problem. As already mentioned the zenith problem seems solved. One issue I would have with a flap type.door is the sail effect from even light winds. As yet I haven't an a.seer to this- my dome has an up and over sliding door. If you fit rails so could this...

Depending on where you are, also happy to share fibre moulding effort if it gets that far. Originally when I looked at geodesic domes I was going to create a steel bar frame with acetate panels. Even that wasn't that heavy.

Mike

[pete_l]

Yeah was thinking about the zenith, only real way to do it still using a geosphere is to have many more faces...

Or to make a full dome and cut a slot in it

[JamesF]

Regarding fibreglass domes, a few people have done them that I'm aware of. One I definitely recall used a mould to make eight(?) sections that joined together to form the entire dome. I'll see if I can find a link.

James

[JamesF]

Here you go:

http://oldsite.astro-sharp.com/dome_building_1.asp

Also linked from that page:

http://homepage.ntlworld.com/k.venables/new/html/The%20Observatory.html

James

[Pig]

I think its a great idea Sam - looks the part too - I know there are quite a few old playground roundabout mounts hanging about you may be able to find one to help with the rotating issue.

[gkec]

An ex-colleague of mine used to (may still do) make fibre glass domes. The bottom of the dome was U shaped so that it floated in a ring of water. Made it easy to push round and the tolerances were not as tight as if you had to build a circular rail.

http://www.green-witch.com/stargazer/swansea5m.html

When he explained it was going to float we didn't believe it would work despite the maths saying it should. We were proved wrong!

[upahill]

I like the idea of geodesic design, but that's all it is - an idea. The reality of it I guess is that it the number of panels would probably outweigh the time it would take to construct a fibreglass dome (there would also be way to may points for water to potentially seep through.

A combination of a geodesic dome and a 'normal' sliding opening might be a good compromise.

[laser_jock99]

Google 'geodesic observatory' and you'll get plenty of ideas. I think you can even buy a kit in the States.

[upahill]

Have found plenty more links, love finding the old sites too, especially when they say things like "It's all hooked up to my computer which is a Pentium II 200Mhz"

I am very keen on trying this, so will have an experiment in a few weeks and see how I go.

[JamesF]

Looks like this could be an interesting and informative source:

http://tech.groups.yahoo.com/group/GeodesicObservatories/

James

[upahill]

Got my new mancave cleared out today.

Got a lot of junk to put back in but should be enough space left to try and build what will be a foam/concrete geodesic design.

[laser_jock99]

Got my new mancave cleared out today.

Got a lot of junk to put back in but should be enough space left to try and build what will be a foam/concrete geodesic design.

Now that's what I call a shed!

[upahill]

Lol, its litterally 6 times bigger than our house/cabin!

[ollypenrice]

It seems to me that your starting point is the idea of a dome-like structure. Do you really know why you want this? What is good about dome-like structures? They are complicated to build and they are highest in the middle where you can't stand because the telescope is there. Apart from looking like observatories, what advantage do they have? You can make a nice simple rectilinear structure which rotates, offers easy access to the zenith and has standing height all around. I really can't see a rational reason to build a dome, especially a small one. If you have such a reason then I'm all ears, but if you start with the idea of building a functional observatory, would you invent the dome? The professionals are busy un-inventing it...

Olly

[upahill]

In this case its use as an obsy would be secondary, the primary goal was to experiment with lightweight geodesic designs for nothing more than my curiosity. When we eventually get sorted we will be moving to france and wifey wants to build a geodesic studio (and maybe house!) so its all good practice in understanding the construction etc.

I do have a design in the back of my head that would make for a very easy to construct obsy, but still laying it all out. Would be simple and quick to build, and could be built on a budget - which is a good goal to have.

My heart isn't set on a dome shape as such, its just one of many ideas im running through.

[Gina]

Are you going to replace the Yorkshire boarding on your shed with something more weatherproof?

[upahill]

Unfortunately I cant, its rented, but I might well be attaching some plastic sheeting to the inside of the framework just to keep the majority of the rain out.

Weather affects about 2' in around all walls, but the centre rarely gets damp. Its dirt floors in their at the moment so I will probably lay some areas of paving to put storage sheds on etc.

[ollypenrice]

A geodesic house would be fab. It's an incredible structure.

Olly

[Alfven]

Hi All,

I am a complete newbie, but whilst waiting for First Light with my new telescope I have been reading through some of the threads on here about DIY observatories. I have quite a big barn which I could build one in, ready to move the garden so I was thinking about different designs which would look good, and also be easy to produce in a kit-form for anyone else who wanted one.

Anyway I came up with this so far..

I think for my own use I would want it to have a diameter of approximately 2.5m and have a decagon wall around 1m high. The idea being that the panels are all constructed in a modular fashion that can be bolted together in a hour or two max. Each panel would be PVC outside, bonded to a 50mm Celotex or similar insulation with a wooden (or maybe ABS) framework. So the whole structure wouldnt weigh very much.

The central hexagon (shown as missing) would lift up using some form of linear actuators meaning it could be opened and closed electronically via a remote, the section of wall underneather would obviously be a door.

The next challenge would be to make it rotate on its supporting wall. Which I would probably do using a steel circle mounted on the wall with a track that the decagon roof would 'click' into. This could then probably be motorised/automated somehow.

Anyway, at the moment its idea stages, but I need a new project to sink my teeth into and keep me busy on cloudy evenings.

Thoughs appreciated.

Sam

I think it's a brilliant design. Looks strong and the panels will nicely disrupt and foil wind pressure. I'm sure you could hinge the panel above the front apature to fold open in two sections or even backwards., to give you access to the Zenith. Looks nice to.