Instructables
Geodesic domes are light, strong structures with huge interior space that is very pleasant and inviting.  Unfortunately they tend to take many man-hours to erect.  I wanted a dome that could be easily put up by one or two people in short order. Hence the Folding Geodesic Dome, also known as the Democracy Dome since it's made from recycled political campaign signs.  With another election coming we may get some new raw materials soon...  Unfortunately this concept is not yet strong and windproof enough for the desert, but testing is underway for a more secure way to attach the segments.  More on this later in the Instructable.

It takes 105 triangles to make the particular dome shape I wanted (called a 3V), which could be a time-burner to assemble.  The Folding Geodesic Dome simplifies things  with tape hinges that pre-connect many of the triangles into 16 segments, each of which can fold into a small stack and connects to its neighbors via tabs and clips. The more hinges used the less time spent connecting triangles in the field.  The dome goes up with 2 people in 2 hours or less. Takedown time is 30 minutes.

There are great Instructables for light domes made from coroplast or cardboard which negate the need for a support frame. This dome was made with an eye for economy, using 20 surplus 4’x8’ 4mm coroplast political campain signs found on Craigslist for $100.  The panels can be made from any stiff material  (cardboard, coroplast, thin plywood, plexiglass) that is rigid enough to resist bowing.

This project was made possible by the resources at desertdomes.com including their dome calculator, dome formulas and the dome diagram that I use in this Instructable. (If you build a dome, please donate to desertdomes.com as I did.)

This dome is a light-duty ‘backyard’ dome, done as a proof-of-concept; it isnt’t waterproof or windproof enough for open country yet.  My next version will utilize a combination of thin plywood for the hexagons and coroplast for the pentagons (to let light in) and will address weatherproofing.  This project was a runner-up in the ShopBot Contest - most exciting!  Thanks to everyone who took the time to vote.
 
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mrsgyver11 days ago
Cool idea I've seen homes in the Bay Area that look like that, and i've always admired them.
doodlecraft2 months ago

wow, cool! :)

openworlder7 months ago

Bob,

I love your folding "Democracy Dome"!

Is there a way that you might be able to upload a Sketchup model of it to Google's 3D Sketchup warehouse?

Later this month, we'll be doing a demo of a 3D printer at a local school
in the Shenandoah Valley – and would like to be able to print out some scale models of your design. (I'll be delighted to send one to you if we can find someone to help in preparing the Sketchup model.)

After the school workshop, we'll launch an Kickstarter campaign to fund construction of an actual
popup dome along the lines you've set out, as a venue for ongoing 3D printing "learning labs".

In the
course of doing research on affordable domes, we've found two links that may enable your coroplast sign dome to overcome wind and rain challenges, and make it
easier for people to enter and exit.

The wind/rain problem might be resolved with an overlay of burlap soaked in about $200 worth of this remarkable thinset cement:

http://www.instructables.com/community/Ever-heard-of-Ceramicrete-MgO-cement-Magnesium-c/

And the access could be made easier by including a playwood hexagonal base such as the following:

http://www.worldwidetelescope.org/docs/WorldWideTelescopePlanetarium.html

I
hope these links may help. We're excited at the prospect of using your
innovative design to help awaken interest in 3D printing and other
makerspace opportunities. Look forward to any comments and suggestions
on moving ahead!

Mark Frazier (mfrazier@openworld.com)

lmason11 year ago
Just worked out that what you call Coroplast is called Coreflute in Australia
guddagudda22 years ago
another thing is can you just cut same size triangles and connect them and not do the math to do it. i also want it to have a radius of 5.5 ft so i don't understand how to figure it out because the website is confusing and also how to connect them i don't understand
guddagudda22 years ago
Hi is there anyway you can make it without the political signs(such as another material) if so what do you suggest. i would like to take it camping with me! thanks!
derrickcan2 years ago
She's a beauty, always been a huge fan of domes! Looks to be a lot less time on setup than a yurt and more travel friendly! I was trying to count how many pieces of pvc pipe one would need to join every tab? I got to 49 for sure and then maybe 60 total? Oh and would the structure support a tarp tossed over in case of rain? Thanks!
yourpalsparky (author)  derrickcan2 years ago
Just counted again, 60 tab connections it is. The dome would easily hold a tarp over the top, though flapping could be an issue unless well secured.

I also like a "flying" tarp suspended over my tents, keeping 99% of the water off the tent. When kept taught they won't flap in the wind too bad. If no trees available to suspend one, I use 8" tall garden/tree support poles to hold up the corners. A 10' pole would clear the top of the dome pretty well I think.

Thanks for the comment!
trevormead2 years ago
Beautiful dome project! Is there anything in the deployment that prevents it from being assembled top-down, instead of bottom-up? I wonder if that would lend to less fighting with the support poles.
yourpalsparky (author)  trevormead2 years ago
I think there's a good argument for top-down, but haven't tried it yet. I've worked on an assumption that much of the dome's strength comes from the lowest tier being directly attached to the earth, creating the perfect "floor" for the dome and giving rigidity. Yet it's quite floppy till you get most of it up, so maybe starting with the structure first and tacking it down later might work.

If you built it with the tabs on the outside for a smooth interior, you would need to build it top-down to reach the tabs on the upper segments.

The poles get easier after a couple of runs, but it can be pretty comical to move one thing and have them all try to fall on you.
Excellent! I'll give it a shot and report back, I'm building one for a regional burn in Colorado.

Have you found any other materials that would lend to waterproofing? A campmate built a hexayurt out of insulating panels last year, I'm wondering if that might be a path to investigate; though I wonder how well the tabs would stay attached once scored, even with a strong tape.

As for the seams... short of adding an extra layer of waterproof tape on the outside, that's a tricky one. There's always Great Stuff, but man, that stuff is a pain, and not ideal for repeated setup/teardown.
yourpalsparky (author)  trevormead2 years ago
I think that I've got a fair solution to waterproofing. I'm going to tape all of the tab-hinges to seal the open flutes that get exposed when one face of the coroplast is cut. This should also add friction to the face of the tabs. Along with some of the tack spray mentioned in these comments, it should seal the tab connections well and add strength.

I'll take some pics and update this Instructable to show the method. I'm going to the desert first week of May and will be setting up the dome for another trial, so I'll include some pics of that as well.

Send some pics of your project!
ilpug2 years ago
I noticed you used what looks like lengths of PVC pipe for clamps to hold the pieces together. Am I seeing that right?
yourpalsparky (author)  ilpug2 years ago
Yes, there is a pic of one (on the materials page I think) showing a lengthwise slit with notches at each end to help get the tube clamp onto the tabs. This gives more linear 'clamp' to the tabs. This along with using tack spray on the tab faces should make it strong enough for bigger winds.
Ok, that looks like a great clamping method, however, it seems like it would be annoying to slot all of that PVC. How did you do that? I am thinking of putting grommets on my tabs and using small bolts.
yourpalsparky (author)  ilpug2 years ago
That would be plenty strong. I've even thought about taking out a big stapler to tack the tabs into place, and the proper staple remover for take-down time.
AmyLuthien2 years ago
If you made one of these out of a clear material, it would make an outstanding greenhouse/cold frame for starting the garden earlier in the spring. :D
yourpalsparky (author)  AmyLuthien2 years ago
I'd like to make one out of one-way mirror plexiglass - shiny outside, unobstructed view inside. Reverse at night though I guess....
Kind of like those public toilets in London? :D
yourpalsparky (author)  AmyLuthien2 years ago
Exactly!
tjk942 years ago
Awesome!!!

I am definitely building one of these to use a a temporary/portable gazebo...I will probably do a 2v Icosahedron though to decrease setup time.

Having worked with these before do you think this setup would be stable or should i just do a smaller door like what you have? The final build will be 8 feet tall and built out of the same material you used. Also, how stable is yours without the poles?

Thanks!
dome proto.png
yourpalsparky (author)  tjk942 years ago
That's nice big door! The structure loses integrity when you lose triangles, which is a drawback to using a panel-based structure. I find that my dome gets a little 'saggy' around the doorway, so using just 2 poles to give the doorway some support really helps.

The door in your pic looks awesome, but I think coroplast wouldn't hold it's shape with that big a hole. The dome is somewhat floppy as you build it, getting firmer as you add segments; losing this much support may be trouble. Using a stiffer material like plywood might change that.

Perhaps get some free cardboard and build one out of that as a testbed, then use your findings to make the final one from plastic.
Yeah i figured as much...I'm currently building a scale model to test that.

My plan is to put a pole on either side of the door hole with a diagonal strap to...this will make more sense with a diagram...there.  The red would be a pole and the blue would be a string/rope holding in that corner.

Anyway we will see how the model holds up and move on from there :)
dome proto x2.png
yourpalsparky (author)  tjk942 years ago
That looks really simple and functional - and you get that awesome big door out of it!
from my scale model test I think the door itself will actually be the most unstable part...however the larges size of coroplast I seem to be able to find anywhere is 4x8 feet which would be hard to fit the size and number of triangles I would need onto, so I still have quite a bit of planning to do.
yourpalsparky (author) 2 years ago
My efforts here are humbled by Rob Bell, who builds the finest "domes" I've ever seen. The defining feature of his math is that all edges are of equal length - only the corner angles vary. Worth a look, with more info readily findable online.

Short video that explains it well: http://www.thetalentree.com/zonotopia-by-installation-artists-at-the-burning-man-festival/

Nice pic by the builder: http://www.vectric.com/forum/viewtopic.php?f=5&t=12257

I'm a maker, he's an artist. This is what inspires me to start designing digitally and outputting to a CNC.
Forn Man2 years ago
Great instructable! I've built a couple of these, but never out of coroplast. Great material for something more permanent. My initial thought was that this could be a fantastic hunting base camp-type structure. It would be much nicer than a tent. I wonder if a suspended tarp over it would provide rain protection.
yourpalsparky (author)  Forn Man2 years ago
I think so - corner poles with taught tarp between them, or even trees if you got em. Even when I tent-camp I like a tarp suspended above the tent for shade or rain protection. I also think a rain-fly nailed down at the corners could boost strength against big winds.

If you cut the dome shapes with tabs folding upwards, you would get a smooth interior with ribs outside. It would keep the tarp off the dome for better air circulation between them; might be hard to clip it together from the outside though...

I do like the dome for it's lack of flapping in the wind; ideally I can get it waterproof sans tarp.

Keep the ideas coming people...
randomhand2 years ago
epic idea! how waterproof is it, do you get good run-off? being from the UK, rain is quite a big issue.

Also you should make a video of you putting it up, or a stop motion?

good luck with the contest.
yourpalsparky (author)  randomhand2 years ago
Thanks! Unfortunately the instructable lacks a couple of the steps like cutting out the triangles and a stop-mo film like you mention. Waterproofing would be great, and I think V.2 will be tighter in the seams where tabs meet, so we'll see. It's the classic drawback for domes. This version is best for the desert.
Chronolapse is a free time-lapse program for capturing & creating video, it works off your webcam or captures screen shots from your computer. It's really easy once you get the hang of creating the 2 folders needed for each video.
You could also (providing you have a large enough memory card) video the construction, transfer it to your computer then speed it up in windows movie maker. (if you use a PC - i'm sure mac and linux will have a similar solution.)

Just right click on the footage in the timeline, click 'effects' then select 'speed up double'. Click 'add' to add this effect to the footage - you can do this more than once - then click ok.

After that you just need to export it.
yourpalsparky (author)  wakojako2 years ago
I think I'll do that next time I raise it; a time-lapse would really show off the method I found for easiest raising. The dome can be quite a handful during erection as moving one support pole can cause all the others to fall at once and give you some exciting moments. I took a while to come with an orderly process to get the thing up easily with one or two people.
m9132 years ago
Nice work, yourpalsparky. 2 thoughts:

1. If you attached the pieces not with clips, but with something more durable, maybe that would solve your slippage. I am thinking holes through adjacent tabs, with zip-ties through the holes. However, when you took it down you would have to cut and dispose of dozens of plastic zip-ties.

2. How much does the whole thing weigh when disassembled?
gnewton m9132 years ago
There is a bolt that has two small balls at the end and you can press them in by the top button. that would make it much more durable when camping lol.
gnewton gnewton2 years ago
Hey I want to build this for camping. I have an idea as to what to use for weatherproofing. If its okay with you I do have some ideas on what to include in a version 2.
yourpalsparky (author)  gnewton2 years ago
Bring on the ideas - this project really brings out a lot of creativity in people when they see it - almost everyone who's interested starts coming up with ideas on various elements, all of which can stand improvement. This was really a proof of concept, I wasn't sure it would even stand on its own until it actually went up in the backyard, so there's lots of room for future upgrades.
yourpalsparky (author)  gnewton2 years ago
I like those - if I machined the holes accurately, it would make a strong solution. I'm looking for some kind of cam-lock that like a bike quick-release that could give it that solid connection.
yourpalsparky (author)  m9132 years ago
Tabs are the next big area for improvement. Thoughts are:
- a peg/hole setup where once the tabs met they wouldn't be able to slip sideways, leaving the clip to deal with less work. Would be for dome with wood tabs.
- tape faces of the tabs to add friction
- the tack spray suggestion, which is a new idea for the dome. The tacky tabs really don't seem to slip during my testing, but haven't done the full dome with it yet.

As to the weight, guessing maybe 50 pounds give or take for the stack, plus a bag of clips and a tarp.
grimdaddy2 years ago
Very cool. What materials would you recommend for a more rainy area?
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