Instructables
Geodesic Domes are awesome.  This Instructable will show you how I built a 20' dome for about $250, with the majority of that cost being the greenhouse plastic ($167 with shipping.)  That's right, the structure itself cost less than $100!  I will also write about what is wrong with this design, how it came about, what I learned from it, and what you might want to do if you're building your own.

Buckminster Fuller wanted his dome houses to be cheap, quickly constructed, and portable.  Yes, your house was supposed to be able to be picked up with a helicopter and dropped off somewhere else!   The Marines experimented with it in the 60's.  There are pictures of domes being flown around.

My purpose for building domes is the same as Bucky's:  to save humanity from extinction.  We are currently building houses the same way as we did thousands of years ago.  Bucky said we would adopt his new technologies only when it was absolutely necessary.  Well, the time has arrived.  Here is why YOU should be living in a dome:

1)  They use far less material than a square building
2)  They are much stronger, domes have withstood hurricanes and tornadoes, even a nuclear blast 
3)  They use less energy, the oft quoted amount is 30% less, but it goes up as the dome gets bigger

I am submitting this as part of the "Win A Home Fabricator" contest.  If I had had one when this started, it would have shaved days off of construction and lots of frustration.  My next dome will be made out of bamboo, and hopefully use home fabricated vertices (the connectors between the wooden struts.)  So if you like this Instructable, please rate it highly so I can make a better dome next time, and work toward that goal of saving humanity from itself.
 
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Very informative. I like the way you talked about having all the "fun" during set up. Thank you.
Tom 72 years ago
Rather then tape. you could use a light nylon line and a Constrictor Knot on the rubber hose.

http://en.wikipedia.org/wiki/Constrictor_knot

great job fella
MrAdventure (author)  Tom 72 years ago
I'll pass this on to my brother, he was wanting to build his using some sort of lashing technique. Have you ever seen this in action on a dome?

Thanks!
The Desert Domes site has a whole section on Bamboo Domes, put together using lashings.

http://www.desertdomes.com/bamboo.html

In this case a V3 dome is lashed using only two sets of 4 point vertices. Since all of your struts are components of your vertices, set up and construction consists entirely of preparing vertices and lashing those together to form struts already in place in your completed structure.

The whole design and measurement system is set up to build from the top down, as opposed to a bottom-up construction, making it easier to place and attach your covering as you construct your dome.
MrAdventure (author)  pcoates2 years ago
That's exactly what my brother is doing, although he hasn't made much progress this summer. I helped him lash the first few together, and it was actually really easy and fast.
... and i quote; "... Zip Ties are a wonderful thing. :)"
rickharris2 years ago
I guess you don't get wind where your dome is!

It should be anchored to the ground with either 3 foot long 2 x 2 stakes or rebar hooks or it will blow away.

Tape is never going to be a satisfactory solution to securing a structure.

Glue the rubber pipe onto the wood or put a small screw through the pipe on each - Amazingly a normal hand screw driver works just as well as the electric ones.

see http://www.instructables.com/id/Geodetic-greenhouse-low-cost/
MrAdventure (author)  rickharris2 years ago
Thanks for the comment. I've already replaced the tape with screws, it wouldn't have taken so long but my drill was on vacation.

I have been considering the anchors. I'd like to make them removable, as it's a portable structure. You'll notice it's in two different spots in the pictures. It does get quite windy here, so I must prepare!
you can get " dog leashes" earth screws for cheap at china mart or pet store, this would hold your dome down.
Buck Minster Fuller himself noted that a large enough dome, one half mile by his estimate, would create enough heat on the interior via solar energy, to lift the entire structure off the ground, similar to a hot air balloon.

For a simplistic, inexpensive, and rapidly mobile anchoring system, try attaching one gallon plastic bottles full of water to each of the vertices once removed from the ground, around the perimeter of your dome. Each of the bottles would weigh 8 to 9 pounds (1 gallon distilled water equals 8.4 pounds) and with enough string could hang one to 2 inches off the ground, providing an extra 120 pounds of Anchorage to your structure.
MrAdventure (author)  pcoates2 years ago
Yes, two or three iterations from now, mine will fly! Muahahahahhahahh!
MrAdventure (author)  rickharris2 years ago
I like that greenhouse! I have the same problem with the joints, they are a little floppy. When it's all together, they hold very well, but with a load pushing directly down on them, it inverts the hexagon or pentagon. This happens because neighboring vertices all slip and fudge around enough to give the one I'm pushing on enough room to flip inward. A backing, as in the instructable you linked to, may be able to take care of that.
SSimon2 years ago
Nice work. I built a 28' diameter 4/8 dome in 1975, using 2" x 2" stock. I milled the stock with an Alaskan brand chain saw mill from a Douglas fir log about 18" in diameter. Made all of the vertices from 3/4 plywood which I got as scrap from a cabinet makers shop. Cutting them was tedious with a hand saw, then clipped the tips off to leave a 1.5 inch flat normal to the strut vectors. Each strut was cut for half-lap joints on the ends, and then wood screwed to the plywood vertices. My only power tool was the chain saw. Building the dome frame cost about $10, mostly in chain saw fuel and wood screws.

I wanted a durable, cheap, insulated covering, so I covered it with the cheapest thing I could find - a surplus Army parachute, stapled to every strut with furring strips. Then I used a commercial spray rig (my Dad's company owned it) to cover it with about an inch of spay on foam insulation, covered that with 3/4" mesh chicken wire, then another inch of foam. Let that cure a week, then painted it with asphalt mobile home roofing compound. It is still standing, on my brothers property, which frequently gets 18" or more of snow in winter.
MrAdventure (author)  SSimon2 years ago
Wow that sounds like you're hitting a lot of the things I was hoping for on the next episode. How much did you spend on the chicken wire? Did you Dad say how much the foam would have cost if it wasn't in the family? Was it closed cell or open cell foam? How is the inside temperature during the winter? From my research the spray on foam seems like one of the quickest ways to take a dome from frame to complete.

Thanks!

It was a long time ago, but as I recall the chicken wire was $18 for an 8' by 100' roll. I bought three rolls, so $54. If you know what "hog rings" are as used in upholstery, then you'll understand when I tell you that I used those to edge join the sections of chicken wire. The foam was closed cell polyurethane foam. My Dad owned the spray gun and mixer, I bought one barrel of each liquid component through his company, and spent $84 on them. I really don't remember the cost of the two 5 gallon buckets of asphalt roofing paint, or the rollers - it was pretty cheap.

My brother repaints the dome every 5 years or so, and he also sprayed the interior with Kilz epoxy sealant paint, and installed two bi-metallic coil thermostatically opening vents at the peak - those are still available, made for greenhouses. It is quire warm inside, even when buried under snow. He has a "dairy barn" type small electric heater in it.

I actually built 5 domes, in total, but only the one geodesic. The rest were experiments, and two of them failed pretty quickly. The other two stood up quite well, and one of them is still being used as originally installed - as the roof of a hay storage/stable which is 24' in diameter. We set that one on a frame that lifted the lower edge of the hemishere 8' feet in the air, while leaving the opposite edge 4" off the ground on framing.
MrAdventure (author)  SSimon2 years ago
This one has actually failed now. I am going to post some pictures, and a write up, shortly. It wasn't the dome, or the materials fault, it was operator misuse. I picked it up (with two other guys,) and we moved it onto a slope, so I could use it to keep cows out of a garden area. The slope caused breakage, and a very long, slow process of destruction. I let it happen in order to see the results, and I'll post it as soon as my camera is rounded up.
I tried this in 1970. Blew away in the first high wind. Nothing of value could be salvaged. Hope you have better luck .
MrAdventure (author)  saitaiable child2 years ago
Yes, I still haven't figured out a good, movable tie down system. If I've got it attached well enough to not blow away, the way I think it might get destroyed is just by being flattened. We'll see! Thanks!
I had a thought. what about the tent weights used for art fair tents? assuming the structure can support that much weight, but it would not have to be very much per "leg." http://keletica.com/keletica-dialectic/44-howto/70-weighty-subject.html
MrAdventure (author)  saitaiable child2 years ago
That would probably work very well.
Get some "ground screws" to tie them onto.

They are removable.

6 or 12 of them 40cm long 6 - 8cm diameter.
Covo2 years ago
So here is a question from someone with very little geo-dome experience, just this 'bile and some observations...

At our local playground is a geo-dome play structure (old school style). what they did was take metal pipe and pinch the ends flat and put a bolt through the connections. ( they "finished" it with a large 4' washer on the outside).

So why could you not just do the same thing with PVC? That is , heat the ends, pinch them in a vice and drill a hole. The only hitch would be the "length" in the dome calculator would be the distance between the holes. This can be done with a simple jig. this would address the rigidity issue, and simplify construction.

Any thoughts?
MrAdventure (author)  Covo2 years ago
I've had some friends back here that have been asking about PVC as well. I preer to avoid it because I've heard it's pretty toxic. Even if it isn't, when it breaks, then I've got a million little shards that are going to be laying around forever. But if one were to use it, a friends suggested that you could heat it up in order to bend the connectors to the required angles (which I believe are listed a couple comments below.

The galvanized steel would make a super strong dome, but I didn't want to spend the money on it. My neighbor has some that we will be using to build him a dome though, so stand by for an instructable on that.

Thanks for writing!
The ones that bent were, I think, 1-inch electrical conduit. Whatever that was in 1970, probably steel.
MrAdventure (author)  saitaiable child2 years ago
Electrical conduit makes some seriously strong domes. If I had a bunch extra of it sitting around, I'd use it. My next one will be with 2" x 6" 's, because it's going to be ginormous, and I have a lumber yard right up the road.
Make up a universal cutting and drilling jig.

Some angle iron about 120 - 160mm over size, 3 holes - one to put a bolt into as the cutting stop, one as the locating pin, and on as the drilling location hole.

As long as they are all exactly the same length....

i don't know what this means.
Well go and do some research of your own - and learn.
The problem is not that they "need to do some research of [their] own - and learn." The problem is that you posted a semi-coherent sentence with zero context.  Let's break down the core of your post, which is pretty much just the one sentence...

"Some angle iron about 120 - 160mm over size,"
Comma denotes a break.  So let's look at this... Yeah, I know what angle iron is.  What context you mean by "120-160mm over size" is anyone's guess.  A Google for "120-160mm over size angle iron" isn't going to return anything helpful.  By carefully pulling apart the sentence, I'm assuming you're saying the piece of angle iron is going to be the base of your jig and needs to be 120-160mm longer than the strut you're trying to make?  But I can only guess here.

"3 holes - one to put a bolt into as the cutting stop, one as the locating pin, and on as the drilling location hole."
Where are the three holes going?  The cutting stop for what?  Sure you're making a "universal cutting AND drilling jig" but what are the bolts going into?  The angle iron that's about 120-160mm over size?  And what is the "locating pin", and the "drilling location hole" locating?  And for which drilling?

Your sentence didn't make sense.  Covo stated that.  I'm stating that too.  Getting snarky and saying, "WELL GO DO SOME RESEARCH" is not the appropriate response.  I know you're good at being helpful when you want to be (I particularly liked your 'ible on using polyfill for a pool filter - will be doing that for my hottub once we get it running).

I would honestly be interested in knowing what kind of jig you're talking about, and how you picture it should be constructed.  I would actually like to build one of these domes as a greenhouse.
Be nice! We're all here to learn...
Not sure about PVC, but there have been people who have used galvanized electrical conduit. PVC seems to get a bit brittle over the years when exposed continuously to UV.
PVC isn't UV or temperature stable- 3 months in direct sun and it starts to disentergrate- CPVC (the grey kind) is better, but more expensive and more flexible-

I built a lot of crazy stuff with PVC (google Sam's Nascar simulator) but nothing that will get a lot of sun---
21cmcgyver2 years ago
I built one like this a few years ago using PVC pipe, black rubber hoses from some old washing machines and some cable ties (zip ties). The plastic cable ties work great for securing the struts to the hose connectors. Great job!
MrAdventure (author)  21cmcgyver2 years ago
Thanks! Zip ties are a wonderful thing :)
riff raff2 years ago
Yay! Ron Paul! ;-)

(re: Ron Paul bumper sticker in pic.)
Yeah, nice sticker! This one gets a vote-up for general intelligence! ;o)
MrAdventure (author)  Calyptratus2 years ago
Great, you must be believers in Liberty and the Bill of Rights!
Indeed sir! (and a dome-o-phile)
KEUrban2 years ago
Pretty scary rounding the ends of the struts... Have you ever seen rotary tenon cutters like this?

http://www.rockler.com/product.cfm?page=11459&rrt=1
MrAdventure (author)  KEUrban2 years ago
Yes, I did get bit once. Those cutters looks pretty great., but it's kind of expensive. At that price you're already a quarter of the way to a home fabricator, and printing out the vertices yourself.

http://www.makergear.com/products/3d-printers

Thanks for the comment!
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