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.
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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A “3V” geodesic or polyhedral dome is made of hexagons and pentagons, which means you will need 2 basic triangle shapes, called BAA and BCC. Start your project with a visit to desertdomes.com, where you will find dome diagrams, dome formulas and an invaluable dome calculator. This Instructable is for a dome with a 7’ radius; this is a “5/8” 3V dome meaning taller vs flatter, over 8’ tall in the middle. The dome likes a flat surface to sit on making it ideal for the open desert playa, not so suitable for uneven terrain. The dome base isn't exactly flat, but close; the flexible nature of the coroplast bows and yields a little when you deploy it to make up for any uneven contact (Note: the prototype pictured here has a radius of 7.2’ but wasted more material from a 4x8 sheet. My next dome and this Instructable use the dimensions for an 84” radius - 7')
The dome is composed of 3 basic folding segments: a pentagon (5 triangles), a hexagon (6 triangles) and a “hexagon plus 3” (9 triangles for the base row ). Each segment unfolds and is clipped into a convex shape with binder clips or a clamp made from pvc pipe.
To calculate the dimensions of the 2 triangles (BAA and BCC), use the desertdomes.com dome calculator and enter the dome radius in inches to get get the lengths of the A, B and C triangle sides.
For the radius of 84” (7 feet) we get
A= 29.284” (roughly 29 1/8”)
B= 33.898” (roughly 33 7/8”)
C= 34.642” (roughly 34 5/8”)
I used those numbers to calculate:
Height of BAA = 23.881” (roughly 23 7/8”)
Height of BCC= 30.213” (roughly 30 1/4”)
.5xB = 16.949” (roughly 16 15/16”, for the midpoint of the B edge)
For the 3V, there are 30 “BAA” triangles (to make 6 pentagons) and 75 “BCC” triangles (to make 10 hexagons and 5 semi-hexagons). 1” wide tabs are placed along B edges to connect segments together, and on some of the C and A sections too. The triangles along the base of the dome have 4” tabs with holes for the anchor stakes. Edges that don’t have tabs will have tape hinges that connect to their neighbors. I’ve mapped out where the tabs need to be for every triangle needed in the dome, adding up to 12 different shapes you’ll cut - download the pdf Cutlist for shapes and quantities.
The dome is composed of 3 basic folding segments: a pentagon (5 triangles), a hexagon (6 triangles) and a “hexagon plus 3” (9 triangles for the base row ). Each segment unfolds and is clipped into a convex shape with binder clips or a clamp made from pvc pipe.
To calculate the dimensions of the 2 triangles (BAA and BCC), use the desertdomes.com dome calculator and enter the dome radius in inches to get get the lengths of the A, B and C triangle sides.
For the radius of 84” (7 feet) we get
A= 29.284” (roughly 29 1/8”)
B= 33.898” (roughly 33 7/8”)
C= 34.642” (roughly 34 5/8”)
I used those numbers to calculate:
Height of BAA = 23.881” (roughly 23 7/8”)
Height of BCC= 30.213” (roughly 30 1/4”)
.5xB = 16.949” (roughly 16 15/16”, for the midpoint of the B edge)
For the 3V, there are 30 “BAA” triangles (to make 6 pentagons) and 75 “BCC” triangles (to make 10 hexagons and 5 semi-hexagons). 1” wide tabs are placed along B edges to connect segments together, and on some of the C and A sections too. The triangles along the base of the dome have 4” tabs with holes for the anchor stakes. Edges that don’t have tabs will have tape hinges that connect to their neighbors. I’ve mapped out where the tabs need to be for every triangle needed in the dome, adding up to 12 different shapes you’ll cut - download the pdf Cutlist for shapes and quantities.
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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!
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.
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.
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!
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!
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.
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 :)
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.
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...
Also you should make a video of you putting it up, or a stop motion?
good luck with the contest.
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.
One could also do well with a sealed or painted thin plywood, of good quality like a birch plywood, which I expect will be in my next version.
Thanks for the comment!
components and build a dome in days not weeks months or years. since styrofoam can be had for free at furniture stores as its used to pad shipping
from damage. a cnc router could cut replications of just few shapes. as you have said a geodesic dome caculator gives the rastra demensiions to enter into the cnc machine. another interesting article i had was called geotangent showed an infinate number of shaped structures could be built using the bond beam technology (with proper licences of course) geotangent just did the math using computers. so it be computer generated and fabricated as we call design build. concrete is benign so is styrofoam so ideal interior finish is plaster also benign. no mold ever . the beauty of bond beam is no reinforced re bar except in the slab. so tornado devasted location is idea place to build one. why not just keep cranking out components and build like barn raisng. it amazes me we furnish tents trailers when we could provide real dome homes.