A guy making geodesic domes without hubs came up on my YT playlist recently. I went in skeptical, came away thinking this is the way I would go .. uh, you know, when I finally build my dome-abode.
If you have woodworking skills (and table-saw, chop-saw), it looks like a no-brainer. For better or worse, the guy goes on a long time about the template/jig he creates — its utility become obvious later when he begins to make the panels.
That's beautiful. I'm going to watch the whole video. My main interest is the sealing problem between the individual panels which seems to be an issue with almost any dome build except for the inflatables.
I've built on with hubs and it worked ok, we used thin plastic to cover it overlapping two panels on the horizontal seams but that is rather wasteful in material and allows less light in.
> My main interest is the sealing problem between the individual panels which seems to be an issue with almost any dome build except for the inflatables.
Right. The "natural materials" people ruined geodesic domes. Buckminster Fuller wanted the parts produced in factories, with tight tolerances, and assembled on site. Radar domes in northern Canada and Greenland were built that way in the 1950s, from aluminum and Fiberglas parts, and many are still holding up, abandoned and facing high winds and snow.
The hippie era wood framing with shingles approach works far worse. It's so bad that the author of "Domebook 1", etc. told people to give it up.
On that note: the 'Jacobs' wind turbines were used in those locations under some of the harshest conditions on the planet where such machines were installed and still worked decades later:
Sure, but it's a lot of seams, 100's of meters on even a moderate size dome, they are very deep (typically about 2" or 5 cm) and it add an enormous amount of work to setting up a dome. It also means you can no longer take it apart.
Yes, that's one possibility. One elegant way to do that would be to route a groove in the cross members and then to stick the seal in there. This still leaves a bit of a problem with standing water in that groove and frost.
Same for me with YT recommendations, but I had not watched yet. Bevelled long-cuts and mitres to produce nice joinery. Finish (stain) wood. Assemble pentagons and hexagons as units. Plans and details at:
I came here to recommend the same video. Its is a very interesting design. I think an cool application would be to build this first using semi-opaque greenhouse panels and then building a cabin within the dome.
I think curved lines like the stardomes’ make sense and have some very interesting advantages. The “hubs”, which tend to concentrate complexity and cost on “flat line doms”, are simplified, disappearing in some cases.
There’s some disadvantages though. A flexible structure is not always desirable. Bamboo (or an equivalent replacement) isn’t available everywhere. Also, flat-line domes are easier to cover with flat inflexible materials like wood panels. In short: if you have access to Home Depot and no access to bamboo, flats might be easier for you to build.
The stardome reminds me of the Boyne Coracle, a small rudderless raft made of willow and ox hide. Here's a video from 1935 showing its construction: https://www.youtube.com/watch?v=aCWFDMnKLyM
Reminds me of playground equipment of a similar design, though I think that was a hemisphere design and may have used straight pieces with bent connectors that connected in the star pattern.
from Wikipedia: Geodesic domes get their name by following the shape of a Geodesic Polyhedron, for example the Icosahedron being the canonical example. "Geodesic line" means in some sense the shortest line between two points (usually on a curved surface), where as "Geodesic Polyhedron" means in some sense the least amount of vertices/faces to enclose a volume.
That is amazing! A true example of inspiration by Fuller… these people get it. Instead of writing yet another useless “thinkpiece” about the limitations of Fullers ideas, they were inspired to do even more with even less!
Edit: this idea could be easily executed with carbon tent poles and a nice waterproofed canvas tarp over the top. A portable, easy to build and durable DIY building more substantial than a nylon tent.
These hubs look like they can greatly simplify geodesic dome construction. Lots of people here are commenting on the longevity of plastic or alternatives to geodesic domes, but I think that misses the point. Nothing is perfect for every application, but this looks perfect for getting a dome up quickly and easily.
Several years back I was thinking about the ideal shape of solar panels, and concluded that the best is the geodesic dome shaped structure. This shape will have the optimum sunlight exposure regardless of the location of the sun during the day.
Things get interesting when you start minimizing the total system cost of the solar panels + batteries. Household power usage peaks at dusk and dawn.
In on extreme, you can either aim panels for optimal daily production (minimizing panel count) and buy more batteries, or aim extra panels at the horizon so that you don't have to store as much electricity for peak times (minimizing battery count).
In practice, something in between the two extremes probably makes the most sense, though most installers err toward minimizing panel count these days.
It's interesting to note how optimizing in this way achieves its gains by trading away flexibility, and possibly becoming self-reinforcing.
"Household power usage peaks at dusk and dawn" is true for households on average, during average (normal) conditions. If your energy production is optimized for the average case, you'll face problems when your household schedule changes. Say you take a week of leave to do some home improvements, or everyone in your house is down with a flu, etc. - suddenly, your power usage might become flat, or have more and bigger peaks during the day. It's not a big deal if you're just selling to the grid, but if you're relying on your own solar power, it's now something to plan around - you lose lifestyle flexibility.
At larger scale, if everyone has their solar installation built based on this "working household" assumption the transition from fossil fuels towards renewables turns the "two peaks" phenomenon from something that sort of happened on its own, into something people are being forced to follow, because of energy availability. Optimizing solar panels for morning and evening load suddenly stops following a preexisting pattern, and becomes the cause of it.
For both of those reasons, it's best to overprovision panels or batteries (or both), or, where possible, install the kind that follows the Sun.
I think they need to release a 3D printable version. 3D printing is going to be more expensive and more fragile than injection molding, but being able to print a replacement ball connector or the like is one way this can become a lot more resilient, other than having multiple manufacturers. If they want to become something like a standard then having a work around for that kind of supply chain issue is important, I think.
EDIT: They do appear to make "simplified" 3D models available for download from their hub-part-specs pdf. I suspect with a high layer height like 0.3mm you could print replacements. I understand why they don't advertise this though.
Rather I think they should release a metal only version. I don't trust plastic to live a long and prosperous life in outside conditions, those are not where plastic shines.
As for 3D printing, I guess ABS could work (PLA can melt or become soft in the sun), but I can't imagine a hobbist grade printer producing a part that is comparably strong. The option would still be nice, though. Maybe you just need a prop for the theater, where weather is a non-issue, and being able to replace parts quickly is more important than longevity.
You can definitely print strong enough parts, most 3D printer slicing software is optimized to reduce material cost not to create strong parts. Increasing the number of walls is a good place to start.
I think the term "building" is a bit of a stretch. Mostly the geodesic domes seem to be used as small greenhouses, and don't have enough weight that even a sudden collapse would really damage the occupants. The manual suggest that the maximum weight for the whole structure should be about 60kg. I'm not really concerned that these things aren't meeting fire code either, you know? You can just pick a wall and tear through it in almost all the examples I've seen in the gallery.
That being said the glass transition point of ABS plastic is 105'c, a little over boiling. I'm not worried about ABS from a thermoplastic perspective, although I am worried about long-term UV performance. I'd also be worried about thermal cycles and plants/mold as most 3D printed ABS will take on water.
I think you'd get a few years out of an ABS plastic component in these circumstances, more if you resin coat it or use acetone vapor smoothing, and start with a filament that has good UV resistance.
Either way I expect 3D printed components to be more expensive and otherwise worse than one manufactured by this company, but being able to repair stuff like this if you need to is important and it's not like you can just go to the hardware store and get a replacement one of these hubs.
I'm not sure how that would interact with the mating surfaces in this particular design, I suppose you could paint it after it's already in place though.
There are entry-level consumer filaments that would withstand the UV and heat requirements for outdoor use, such as PETG which is UV stable and as strong as ABS.
By entry-level I mean able to be printed on the everymans Ender 3, <$300 printer with little expertise. There are of course dozens of exotic filaments you can print on a slightly more advanced machine and even that can be done for pretty cheap, <$500 perhaps if you have the expertise to upgrade an Ender and tune it properly.
The benefit injection molding has over printing in this case, is these parts might want to be redesigned to reduce sheering at the layer lines on the peg things.
UV stability is only one aspect. What happens when you build a greenhouse out of these and the temps reach high enough to deform these? How long do you think the structure will stay stable with or without UV paint?
I've had a greenhouse melt nursery pots left in it and they're made out of polypropylene, which has a glass temp 50C higher than ABS.
The inside of your greenhouse is reaching ~150 degrees celsius? Why aren't your plants boiling? Is it just a color thing?
EDIT: the glass transition point of PP is -25C, vs ABS's 105c. I think you confused glass transition point with melting point, they're very different things. I think polypropylene will always be a bit soft, and will hold a shape that it's deformed into, it it hold that shape long enough.
Sorry I think you might just be mistaken. If your greenhouse is reaching 150c then there's actually not that many common plastics that wouldn't hit the glass transition temp. There are some exotic "plastic blends" like glass or carbon fibre/mineral blends that can do it, but even most of those are less than 140c. In this table even the modified versions of polypropylene have glass transition temperatures below negative: https://omnexus.specialchem.com/polymer-properties/propertie...
I don't think it should be too surprising that 3D printing filaments can withstand similar characteristics to other outdoor plastics. One commonly used outdoor plastic is PVC which has a glass transition temp between PETG and ABS: PETG: 80c, PVC: 85c, ABS: 103c. If you left a PVC pipe in your greenhouse you wouldn't expect it to deform.
Looks like a fun project but also illustrates why geodesic domes never caught on as a standard construction type: nodes/hubs or whatever you want to call them are a problem. Most standard construction joints have 90 or 45 degree angles, not the complex geometry found at a geodesic node. While initial construction is not that bad, maintenance and replacement over time (particularly with wooden structures) would be very difficult. All-steel construction of nodes and interconnecting beams, wih careful rust-resistant treatment, might be more viable, but that likely increases costs quite a bit.
They caught on for covering large areas (stadiums, aircraft hangars, etc.) but they don't really make sense on what you might call the "human scale", roughly 3 to 10 meters, say. At human scale wood and metal are strong and light enough that you don't really need geodesic designs. (Wood and metal are geodesic already, just at small scale, eh?)
> The truss measures 8 feet long, 16 inches high with a depth of 12 inches. This is just one of many structures that could be easily built using our square tubes and gussets. Weighing in at just 14lbs., the truss is light enough for a six year old child to lift and carry!
They show that: a cute kid holding it up, no problem. Then they load it up.
> ...we loaded it with 35 80lb. bags of concrete mixture, totaling a whopping weight of 2800 lbs.! Again, we saw no signs of weakness or flexing. We would have put on more bags, but we just couldn't stack them any higher!
Those trusses look very solid. One back-burner research project of mine is synthesizing carbon fiber using atmospheric CO2 as the feedstock, it's fairly involved but plausible.
My art professor lived in a geodesic dome commune in the southern Colorado. Also discovered aperiodic tiling before Penrose who still sued him (and lost).
I've definitely been drawn into the mysterious gravitational pull of geodesic domes. never built one, but as soon as I have a place to build one, I plan on it. I've looked at a lot of different ways to build one.
the trillium domes that someone shared is definitely the 'nicest' version
I've also seen loads of other 'hub' designs.
personally I think zip tie domes are really interesting, seem the cheapest: https://www.ziptiedomes.com/geodesic-dome-hub-kits/index.htm
but seeing this just gave me an idea for a really simple hub design that would potentially be more sturdy than these single screw attached, plastic socket hubs.
what if the hub was simply a pentagonal puck of wood, and the spokes are attached with hinges? the complicated part of building domes is getting the angles right and using hinges mean you really only have to get the distribution of spokes around the hub right and the hinge will naturally fall into the correct angle? anyone got any land I can try to build this on?
sure but then you have to calculate the angle between each hub and spoke and cut the edges of the hub and boards to allow for flush angles when you screw them together. the whole idea behind the hinge is the angle will just naturally fall into place as you're building the structure.
Dumb of me to distract. With hinges you can also build flat on the ground (as with a paper-with-flaps layout), then start to form the shape, "latching" while you go.
Anyone know if these would work for hammocks (I wonder with wood). A friend of mine builds domes with metal, and I know people hang hammocks in them (which is a great system for giving a good number of people a place to sit or sleep). His dome website is here: https://www.edgedomes.com
> The structure’s use of tape makes it far from permanent. If you wanted to make this structure something more permanent–one man mentioned a hunting cabin in the snow–I’d definitely look into something more hardware-based. Something that used hinges/washers/bolts or the like to provide a lot more strength at the junctions
Interesting idea. Something that made me pause was to see that each edge was attached via a single screw. People who know more about construction than me (majority of the world), isn't this a problem if you want a sturdy design?
It doesn't look like there are any pull forces in a dome so I wouldn't be concerned. Mainly there seems to be shear forces which could be a problem if the wood splits.
For end-grain I find estimates of 75% stength on average expecting considerable variation joint-to-joint, assuming proper pilot holes have been drilled. If the hold scales with the diameter of the screw, then a larger screw might compensate.
The square of the wood's specific gravity might dominate differences:
I don’t really understand the geodome fascination. They aren’t very space efficient structures because of all the low hight space at the perimeter that’s difficult to use.
As someone who has constructed a couple, I can attest that they can be a pain in the ass. They do get more efficient as you build larger ones, and they can pack down quite well (the covering for a soft shell dome is usually larger than the structure components). They are also wickedly strong once set up.
I toured three in open houses while house hunting and considered putting in offers. While they can be interesting and pretty cool, you are spot on. They really are quite space inefficient.
They feel nowhere near as big as their square footage listing. Our target square footage of 2500-3000 square feet required an equivalent of 4000 geodesic. The smallest one was 2700 and it felt downright tiny. Their round nature makes room partitioning awkward and unless you purposefully put ceilings on rooms at the top level, you’re going to have situations where the master bedroom opens up to the kitchen via the roof.
I lived in a dome we built out of a kit. It was made of aluminum tubes squeezed into a tab at each end. The tabs of the 5 or 6 tubes were then overlapped and connected with a single bolt.
It had 4 pine trees fall on it during a “microburst”. It ended up deformed and some of the tubes bent but it held up pretty well considering the impact.
Anybody seen similar hardware out of aluminum or coated steel or stainless that's also readily USA-available? Machining these could be done on a small lathe and single-sided CNC...
I actually am building one of these but not from wood I purchased a dome home kit from pacific domes one of the first company's to develop the dome from its originators idea
You can do it on a hill. Draw one up, of your choice, and you will find that in some geometries, there are nearly straight arcs other than the equator. So you can remove portions, so long as you support the remaining intersections appropriately.
(Note that I'm not an architect, but neither was Buckminster Fuller).
Main difference is that on a flat surface the dome weight is distributed across the base "automatically". If you just "copy-paste the default flat-terrain dome" on a sloped terrain, the bottom vertices might end up supporting more weight than the top ones. This might be ok for small/temporary domes. For something bigger/more permanent, you might want to "cut the sphere" in such a way that the weight distribution is as uniform as possible.
Also keep in mind that even on a flat surface geodesic domes a foundation - for example so that they don't fly away when there's strong wind. This would go double in sloped terrain.
If they're being really fancy, they'll create rough-ins for real windows embedded into the frame. But more commonly they'll just punch a hole in the exterior cloth and replace it with clear plastic. Here's some example photos if you're interested https://pacificdomes.com/domes-media-gallery/dome-homes-gall...
If you have woodworking skills (and table-saw, chop-saw), it looks like a no-brainer. For better or worse, the guy goes on a long time about the template/jig he creates — its utility become obvious later when he begins to make the panels.
https://youtu.be/Sl9fEp-27EM