Very cheap dome idea

[BC]

Hi,

I'm not planning to build a dome observatory but just noticed this on All Classifieds http://www.allclassifieds.com.au/toys/outdoor/cubbies-sandpits-swings/steel-dome-climber-climbing-frame-children-kids-ou/ad42045f45fcb4924338877f6559c9619c1 5

A steel geodesic style structure 2.9m diam for $150!! A few technical issues, like how to keep strength after cutting the viewing section but maybe some keen DIY could use this.

I have no link to the seller; just noticed it.

Bruce

[netwolf]

Could this be made into a mould to make fiberglass domes?

[gazob]

I would have thought stretching cloth over the structure would allow you to start layering fiberglass in much the same way curvy speaker enclosures are done in custom cars. Once you have a shell dismantle the dome for the inside and add foam bracing and fiberglass inside. Beef up where the opening is to be cut and then cut the opening.

I personally have no plans for an observatory yet either, but have thought about the type of thing myself with 3d printed intersections and lengths of alu rod.

[rogerco]

Toys-R-Us are advertizing something similar for $199.99 which is smaller at about 1778mm diam.

[Barrykgerdes]

Save your money. Unless you have a decent machine shop etc. converting that structure into a serviceable dome will end up costing more than a commercial fibreglass dome.

Next what would you use to support it. A cheap garden shed would not be strong enough.

I looked at building a domed observatory 15 years ago and decided that a purpose built observatory was the only way to go.

http://barry.sarcasmogerdes.com/observatory/programs/obsvatry.doc

Barry

[ZeroID]

I reckon it's do-able if you're a keen DIY fan. Depends a bit on your expectations and skills. The 1.8 would fit across my tin shed ob eg and let me handle the big scope easier. I'd leave the frame inside and put curved struts down two of the bottom rows of triangles to form the opening slot. Big issue would be, as usual, getting a decent weatherproof seal.
Use thin alum or ply on some surfaces for bracing, maybe weatherproof fabric\plastic for others. .... hmmmm, more thought required.

If I see one going cheap on TradeMe I would be seriously tempted to give it a go ..

[BC]

It sounds like maybe my "thought bubble" wasn't really that good an idea. My apologies. Best take advice from those more experienced in these things and save your money.

Bruce

[simmo]

Use astronomy products boys as a guide. :rolleyes: Make a dobsonian style base using what you can. Use axle as bearing. Mount the frame to the base. Cover with plastic or cloth your call. Only thing you need to work out is how to move it. :question: Flint stone style wheel cut into base that touches the ground, want to move just push it. Or wheel over wheel with handle attached and roll in reverse. As for the viewing area just take out one triangle the structure should still be strong enough to stand up only carrying light covering. Strengthen the opening with some strips of hard plastic or thin metal. :)