Introduction: Folding Geodesic Dome

Picture of Folding Geodesic Dome

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 including their dome calculator, dome formulas and the dome diagram that I use in this Instructable. (If you build a dome, please donate to 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.

Step 1: Design

Picture of Design

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, 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 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.

Step 2: Tools and Materials

Picture of Tools and Materials

- metal yardstick or metal straightedge.
- carpenters square
- carpet knife and some extra blades
- dextrous gloves with tough palms- coroplast can give a mega-papercut
- ladder or stool for erecting
- hammer for stakes
- spring clamps for easier deployment
- (staple gun for wood slats)
- (saw to cut pvc tubes)

- 15 - 20x coroplast sheets 4x’8’, 4mm (use stiffer panels for stronger structure)
- strong duct tape (use gaffer’s tape for stronger structure)
- 200x 1” binder clips (use 1-foot long x 1.5” pvc pipe tubes with a slit for stronger clamps)
- 20x 1’ long round tent stakes (minus the plastic dealy)
- 20x washers to fit the stakes (bigger the better)
- 5x 6’ long round garden poles
- 5x 8’ long round garden poles
- 10x rubber tips that fit the poles
- bag of thin bamboo “garden” sticks 6’ long for vents
- spray tack adhesive
- (15x 4”x24” thin wood slats for stronger base, hole in center, glue to affix)
- (light schedule 1-1/4” pvc pipe to make tube-style clamps)

Step 3: Templates

Picture of Templates

You’ll make 2 templates for the two types of triangle, BCC and BAA. Making the template is complicated to describe, so use the pictures for a better understanding.  The base dimension  (B) is 33 7/8” for both triangles.  For BAA, mark points for the base corners of the B edge at 33 7/8” apart, and mark the midpoint of the two.  The estimated apex of the triangle is a point 23 7/8” above the midpoint of B.   The apex needs to be 29 1/8” from each base corner; and the project needs both edges to be exactly the same length for it to assemble well.  You’ll likely have to adjust the estimated apex until you find the sweet spot.  Draw your A edges from apex to base corners and cut out your template with a straight edge.  Repeat this for the BCC triangle with the appropriate dimensions.  Optionally you can include tabs along the template edges as shown.

From the 2 templates you will draw 12 different shapes as shown on the pictures and listed in the cutlist.  The shapes vary by which edges have 1" or 4" wide tabs.

Step 4: Layout

You will use the cutlist and the templates to mark your material for cutting.

To mark cutlines on your material, place the template and make a mark at the 3 corners of the triangle, and marks to denote edges with tabs.  Use a straightedge to connect the dots for your cutlines.  Important: use a dotted line to draw where your hinges are to be scored - this will keep you from cutting off a tab by mistake. Have all your lines in place for the whole sheet before you cut to minimize mistakes.  You’ll find that many triangles can share a cut with a neighbor to save cutting.   

Important:  when drawing cutlines, use a pencil to denote the B edge of every triangle and write which number shape it is.  You’ll save a lot of time during fabrication of the segments.   You can erase the pencil marks later.

These templates assume that the ‘up’ face of the sheet you’re about to cut will be the outside of the dome, and that the tabs fold away from you.  Double check all cutlines for accuracy against the cutlist one last time, then use the razor knife and straight edge to cut out your shapes from the coroplast sheets.  I regret not having photos of the sheets being cut.  The numbers on these pictures reference the 12 shapes on the cutlist.  You will score this top face of the material along each dotted line to make the hinges for the tabs.

Step 5: Cut Out 105 Pieces Using the Cutlist

Picture of Cut Out 105 Pieces Using the Cutlist

Important:  Use gloves when handling coroplast - it gives mean ‘paper’ cuts.

Important: please don’t cut any material until you’ve made a scale cardboard model of the dome and understand it’s assembly first.  Plus it’s fun.  Use the dome calculator and pick a radius, then do this Instructable with cardboard boxes and make sure you’ve got it right before spending money. 

Coroplast has two skins connected by thin ribs just like cardboard.  I  cut the triangles using a razor knife and straight edge.  This made for easy production without real tools.   Hinged tabs with the coroplast are easy - just cut one face of the sheet  with a shallow razor and fold it back with the other face as the hinge.  The tabs connect together with large binder clips during assembly.

Optional: to make stronger clamps for the tabs, cut 12” lengths of light-duty 1-1/4” PVC pipe. Cut a slit lengthwise into each pipe.  Cut a notch at each end of the slit to allow the clamp to slip onto the tabs.

Step 6: Fabricate Segments: Tape Hinges

Picture of Fabricate Segments: Tape Hinges

To make a segment lay out its pieces (5, 6 or 9) on the floor in the “anatomical” shape with the outer face up, tabs down.  Make tape hinges along alternating edges to connect the triangles to their neighbors.  The hinges fold in alternating directions to allow the accordion effect, using flat strips of tape on the inside face of the hinges.  Once the inside hinges are laid down, fold them and apply tape to the still-exposed outer edges of the hinge  Lastly, use temporary tack spray adhesive from a craft store to add “grip” to the tab faces to prevent them from slipping apart when the dome is under strain.

Use a sturdy staple gun and glue to affix the wood slats to each footer.   The slats will need a hole for stake.

Step 7: Vents and Door

Picture of Vents and Door

Vents can be cut into a triangle with a flap to cover the hole and a stick to prop the flap.  Make a BCC #1 or BAA #10 for the flap.  The flap is removable using velcro so that it doesn’t get crunched when the segment is folded.  The flap for the vent is held open by a thin bamboo garden stick, with the nodes of the bamboo serving as convenient stops for holding the flap up.   I made a small notch to hold the pole at the vertex of the opening.  On the triangle with the vent hole, you will need to adjust where you score your B edge in order to make room for the second tab of the cover flap.  This is a good step to practice on your cardboard model first.

The door is a variation of one of the base hexes, and it is actually detached from the neighboring half-hex.  You will cut the 9-piece segment for the door a little differently from the other 4 - see the diagrams and the cutlist. The hinges are made to allow the door to fold up and out for a diamond-shaped entry - no crawling to get in.  To give structural strength to the doorway, 2 of the 6’ poles get re-purposed into supports, and extra clips are placed on nearby tabs.   Extra tape around the joints on the outside also helps.

Step 8: Deployment

Picture of Deployment

To do this most easily have all supplies stacked in the center of a tarp marked with a 14’ circle, and build from the inside.  Optionally draw a circle in the sand if you don’t use a floor tarp.  Use a stepladder to save time.

The dome will be quite floppy during deployment and hard to manage until you get the hang of using the support poles.  You will need to adjust the poles during the process to allow all edges to meet their neighbors and get the true dome shape.  Moving one pole can make 2 other poles fall down.

Partially unfold the 9-piece base segments and clip them to their neighbors; as you adjust the ring to fit the circle it should hold itself up. See photo. A couple of chairs help.  Once the ring is even, nail down all the footers with the stakes.

Pre-assemble all the pentagons.  If you have a helper, they can put together pentagons and hexagons while you clip them in place from within.  Hang the first 5 pentagons off the outside of the base ring. 

Open a base hexagon up and clip it into its convex shape, then support it with a pole.  Flip up a pentagon beside it and connect them with the tabs; support the pentagon with a pole.   Go around the perimeter and flip up alternating hexes and pents.  See photo.  Finish with one 6’ pole holding up each of the 5 pentagons - things should balance in a sagging fashion.

Next pre-assemble all 5 upper hexagons, hang them all off the outside by their tabs, then flip them up in turn using 8’ poles to support them as you clip them together.  As  you go around, the 6’ poles will fall away and you will need to adjust the tall poles frequently.   Once you’ve added the last hexagon the dome gets firm and the 8’ poles fall down.  Add the top pentagon to complete the structure.

Put in the light bamboo sticks to hold up the vents, and put two poles on either side of the door to support the opening.  For tough conditions use tape on the outside to reinforce connections between segments as desired.  You can put extra clips inside around the door frame.

Step 9: Field Testing

Picture of Field Testing

Updated May 7 '012: The prototype is great for backyard use but not wind-proof enough for open desert.  To make it more weatherproof, I have just taped all the tab hinges to cover the flutes and keep water out.  The tape covers much of the face of each tab to give it extra friction along with spray tack adhesive on all tabs, but in testing this setup still blows apart in strong gusts/dust devils.  Using clips to secure the tabs still allows too much slippage and the panels come apart from each other.

Next method to test: heavy-duty staples to secure tabs to each other, which of course would need a staple-puller to minimize damage to tabs.  This seems like a fast way to erect the dome, but it would slow the deconstruction process.

Once deployed I add short strips of tape across all joints on the outside of the dome to bolster it against slippage, and around the door joints.  I add extra clips to the tabs near the inside of the door.

There is room for improvement in all facets of the “Democracy Dome”, including clips, materials, hinges,  weatherproofing joints, etc. 

The 4mm coroplast is a little soft, allowing a couple of the lower hexes bow just a little to accommodate surface unevenness.  This is also a result of the dome base having 5 'low points' that bend under the load.  One could use thicker stock for the base triangles if desired.  My next version will use thin plywood for hexes and coroplast for pentagons wlong with some tweaking of the dimensions of the lower panels to make it sit truly flat.  I'll post the details once I get a chance to figure it out in SkecthBook.

Putting this up in windy conditions would be problematic; morning while it’s cool and calm is the ideal time.

The dome ventilates well and doesn’t heat up in the sun due to the high reflectivity of the white exterior. With the tall sides there is standing room in most of the interior.  More than enough room for queen airbed and a table.  The light filtering through the blue and orange gives a stained-glass quality to the interior.  Using pure white coroplast would make a really bright interior.

Comments welcome, good or bad.


harleycat (author)2017-11-03

You can melt styrofoam (polystyrene) in acetone. The organic packing peanuts won't work. This makes a liquid plastic that you can paint on cardboard to make it waterproof. Just melt enough polystyrene down to make the mixture the consistency you desire for painting it on. You can also paint it on your lawnmower deck for easy hose-down after mowing, and probably a million other things :) Just be careful of the fumes. Also, corruplast can be ordered online and comes in a multitude of colors, including clear and super clear, which would be perfect if you want to install windows. Thank you for this awesome idea! We'll be building it with our grandsons this weekend, probably a cardboard version with the polystyrene/acetone painted on the outside.

ANDRELAS (author)2016-07-20

Hey, great innovating, guys. I have a modest suggestion. Looking at the "Intershelter" concept, all these pesky hub intersections are replaced with overlapping sperically shaped "dishes". It seems to me that if the BAA & BCC triangles were made so the hexagons and pentagons were 20% greater spans they could just be overlapped and fastened together on the lines of how they put up the Intershelter domes. Cheers.

Cheerfultrout (author)2015-12-31

Just an idea i had looking at this, you could glue Mylar onto the panels and wrap duct-tape around the edges to make it weather resistant. It woukd help keep the heat from the sun off too.

daniel.farris.106 (author)2014-11-07

16' coroplast 4V dome. assembling , thank u for much , still ran into a lot of walls, more pics coming...

Wow - that looks great! I can be slow in responding to my Instructables comments, but please keep me updated on your progress. I just did a build in my backyard of the folding dome, and will update my Instructable with some picks. I've updated the design w some holes in the tabs, allowing zip-ties to keep it tight against the wind. I've also figure out an easy way to make it sit flat on the ground, as the 3v normally has 5 low-spots. Thanks.

finally finished duct taping, steaming the tape helps alot, u get a roll of evenly heat duct tape, goes on really nice even cold, good adhesion , but there have been a few spots that are leaking and I found that great stuff injected from inside into the flanged flutes creates the most amazing results. the foam expands goes in and around creating seals and connections across the abut ed triangles, also used a dab of foam at every intersection, very pleased with results. if I have to move the dabs will pluck right out with little effort just using my hands, the triangles can be separated by cutting zip ties from inside and cutting the tape down the middle of the flanged triangle edges there by separating the tape and the foamed flanges. Also the foam has transfered into the triangle itself creating air locked chambers in the fluting of the triangles. Add a Carbonite window and a small plexiglass one just under it on the south side. inside I have started to use what I can find from trash to insulate, like cardboard, foam sign, coraplast , foam packaging, bubble rap. still need to put the 2' knee wall in and a door that will have a foyer. the 5/8 3V Dome u built didn't need a knee wall cause it's 5/8 of a Dome and this is a 4V dome , which is exactly 1/2 a sphere. So a ladder I can see is a must for a 3V 5/8 Dome. your dome is 2' taller than my 4V and required less triangles, so I can see why alot of 3 Vs are made. I'm a lover of triangles though...The wood stove works well with coraplast a small amount of shielding and to my great surprise , even with knowledge that this stuff is heat resistant it has yet to combust...

Still working at the kinks. There is alot of moisture build up from my own body, it builds on the ceiling triangles , freezes in the night then rains down when the dome heats up, I knew Coraplast is non breathing ,but there's got to be a way to create a breathable dome that still holds its heat?

Maybe you can exchange air depending on moisture content in the air. But air loss = heat loss. Perhaps you are also getting moisture from the fire.

When I build it over my lawn, it's a wet mess inside from morning condensation. In the desert it's fine, as you might expect. I've put a tarp down first and pegged the dome onto it, and it was a lot dryer. The moisture from breathing is a tough issue though... Maybe one of your insulation linings might prove good at wicking/drying during the night/day.

it's in the 30's and duct tape , even gorilla tape is hardly sticking... have learned alot... coraplast is very forgiving, but it's tricky on some cuts that run parallel to the fluting, it changes the location of the bending flange... I did all the triangles with flanges, alot of work... kind of wish I had made u r design, I was working on inserting wire into the triangles and adjoining them together with bent wire, it was way to hard and time consuming and winter is on my heels...I did make the roof separate and pulled it onto the top. I did all this solo...1st dome...could go on about mishaps and unpredictables but I'm still busy and all I got is a tablet...

Steel TitanF (author)2015-10-05

Better idea than plywood: Start with cardboard, soak in fiberglass resin and spray with waterproof fixative. Lightweight, crazy strong, definitely weatherproof. Heavy aluminum tape works great for joints. I suggest a layer of low-glare marine paint (so rainwater rolls off easily) but that's just me.

Wow - great idea! I have been looking at various commercial architectural panels, but they're expensive. Love the idea of strong waterproof cardboard. As for magnets, I've tried some rare-earth magnets on the tabs, but not enough strength as far as I can tell. Currently using reusable/removable zip-ties to secure the panel tabs, which is the strongest cheapo solution so far.

Also, magnetic joints? Love this whole concept, I must say.

peterp8 (author)2014-11-13

Many thanks for sharing your creativity with the rest of the world, occupy indeed !

I would love to make one, but i have an important question, is it possible to erect it from the top down rather the other way round, negating the need for a ladder perhaps

I just built mine and didn't use a ladder just a single milk crate for a little step up. the ladder in my pictures I never used... I too thought I would need one, but I did it buy building the roof separate and dragging it up over the outside walls, like pulling covers over head in bed, it worked, and it was close, somethings u have to think about, leave a section out on the wall so u can reach over the edge to pull up and over the roof.

stefan.hermannsson.58 (author)2014-09-29

Do you have a quick way of calculating the number of triangles given a diameter?

The number of triangles stays the same, they just change in size. This page shows the various "frequencies" of domes. I built a 3v, 105 triangles I think...

mrsgyver (author)2014-09-06

Cool idea I've seen homes in the Bay Area that look like that, and i've always admired them.

doodlecraft (author)2014-06-25

wow, cool! :)

openworlder (author)2014-02-10


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:

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

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 (

lmason1 (author)2013-07-11

Just worked out that what you call Coroplast is called Coreflute in Australia

guddagudda2 (author)2012-05-19

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

guddagudda2 (author)2012-05-19

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!

derrickcan (author)2012-03-22

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)derrickcan2012-03-22

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!

trevormead (author)2012-03-18

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)trevormead2012-03-19

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.

trevormead (author)yourpalsparky2012-03-19

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)trevormead2012-03-22

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!

ilpug (author)2012-02-28

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)ilpug2012-02-28

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.

ilpug (author)yourpalsparky2012-02-28

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)ilpug2012-03-05

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.

AmyLuthien (author)2012-03-01

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)AmyLuthien2012-03-01

I'd like to make one out of one-way mirror plexiglass - shiny outside, unobstructed view inside. Reverse at night though I guess....

AmyLuthien (author)yourpalsparky2012-03-01

Kind of like those public toilets in London? :D

yourpalsparky (author)AmyLuthien2012-03-05


tjk94 (author)2012-02-28


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?


yourpalsparky (author)tjk942012-02-28

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.

tjk94 (author)yourpalsparky2012-02-28

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 :)

yourpalsparky (author)tjk942012-03-03

That looks really simple and functional - and you get that awesome big door out of it!

tjk94 (author)yourpalsparky2012-03-03

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)2012-03-03

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:

Nice pic by the builder:

I'm a maker, he's an artist. This is what inspires me to start designing digitally and outputting to a CNC.

Forn Man (author)2012-03-01

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 Man2012-03-03

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...

yourpalsparky (author)2012-03-03

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.

m913 (author)2012-03-01

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 (author)m9132012-03-01

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 (author)gnewton2012-03-02

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)gnewton2012-03-03

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.

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