[HN Gopher] Geodesic domes made simple ___________________________________________________________________ Geodesic domes made simple Author : mooreds Score : 156 points Date : 2022-12-16 13:08 UTC (9 hours ago) (HTM) web link (buildwithhubs.co.uk) (TXT) w3m dump (buildwithhubs.co.uk) | calebm wrote: | 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 | bilsbie wrote: | How do you install the windows in this? | hklgny wrote: | 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... | FigmentEngine wrote: | linux only i am afraid | labria wrote: | I'm sure NetBSD will be ported soon enough, if not yet... | beefman wrote: | Reminds me of the Starplate system. I lived in a Starplate dome | for a few months in the late '90s. | | https://www.strombergschickens.com/blog/starplate-building-s... | deepsun wrote: | Looks even cooler, more space inside to stand. | Communitivity wrote: | 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? | RobotToaster wrote: | Also you're never really supposed to screw into end grain, it | has half the strength of a normal screw joint. | a9h74j wrote: | Half-full or half-empty in this case? | | 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: | | https://www.engineeringtoolbox.com/wood-screws-allowable- | wit... | | Also, what is the pull-resistance on the snap joints | themselves? | traverseda wrote: | Using a single screw turns that screw into a pivot point. For | geodesic domes though the wood being able to pivot is not | really a problem. | jonathankoren wrote: | Maybe not for the skeleton, but it's certainly a problem for | the outer shell | btbuildem wrote: | Especially given that the screw is going into end-grain. That | is a very weak joint, you could pull the screw out with pliers. | foobarian wrote: | 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. | JKCalhoun wrote: | I don't know. Going into end grain I would want something | with deep threads like a lag bolt. Given enough length | (threads) it could be pretty solid. | [deleted] | [deleted] | penneyd wrote: | Is it possible (feasable) to create a geodesic dome on a hill or | do you need a flat surface to make it work? | otikik wrote: | Yes it is possible. | | 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. | analog31 wrote: | 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). | benzofuran wrote: | 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... | otikik wrote: | You might want to try the Wranglerflange (I have not tried this | myself) | | https://thewangerflangecompany.bigcartel.com | somehnacct3757 wrote: | I don't know about the metal portion of your question, but I | ordered from the OP site just fine with a US shipping address | leashless wrote: | _much_ simpler: https://morganengel.com/nearodesic-polyhedron- | hexayurt-dome-... | | No hubs, it's all 4x8 sheeting and long straight cuts. This one | was taped together, but it could be plywood and screws as easily. | otikik wrote: | > 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 | rdtwo wrote: | 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. | a9h74j wrote: | Seems like a reason to combine with knee-walls or posts, to | make curved space be more overhead. | | Indeed, their gallery shows a good fraction of examples doing | so. | | https://buildwithhubs.co.uk/gallery.html | foobarian wrote: | My problem is the covering. A more linear structure is a lot | neater to cover with a tarp or clear plastic (say, for building | a greenhouse). | [deleted] | snapetom wrote: | 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. | bilsbie wrote: | You could put storage in the low places. | 0_____0 wrote: | 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. | photochemsyn wrote: | 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. | carapace wrote: | 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?) | | - - - - | | A slight tangent, but check out the demo carbon-fiber strut | work here: https://dragonplate.com/carbon-fiber-truss | | > 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! | | We could cover whole cities with domes... | photochemsyn wrote: | 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. | carapace wrote: | That sounds good! | soperj wrote: | > maintenance and replacement over time | | How much maintenance do you do on the wood in your current | house? | jonathankoren wrote: | Fair point in abstract, but geodesic dome houses are | notorious for leaking. Case in point, Bucky's house in | Carbondale | | https://fullerdomehome.com/ | douchescript wrote: | I have one of their kits. Pretty nice kit and fun to build. | traverseda wrote: | 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. | | https://buildwithhubs.co.uk/downloads/hubs-part-specs.pdf | | https://buildwithhubs.co.uk/downloads/hubs-cad-models.zip | graeber_28927 wrote: | 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. | CarVac wrote: | PETG is a better choice for outdoor use than PLA or ABS. | traverseda wrote: | 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. | malfist wrote: | You want thermoplastics sitting out in the sun being part of | the structural system of a building? That seems like a recipe | for a building collapse. | traverseda wrote: | 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. | chucksta wrote: | Everyone always seems to overlook you can just paint the | parts for UV protection | traverseda wrote: | 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. | ehnto wrote: | 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. | malfist wrote: | 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. | traverseda wrote: | 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. | greyk47 wrote: | 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? | a9h74j wrote: | Or pocket-screws in place of hinges? | greyk47 wrote: | 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. | JKCalhoun wrote: | 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. | | https://youtu.be/Sl9fEp-27EM | a9h74j wrote: | 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: | | https://trilliumdomes.com/ | joneholland wrote: | YouTube recommended this guy to me last week despite having | never been interested in a dome. It's truly odd how the | algorithm works. | jacquesm wrote: | 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. | bccdee wrote: | Seems like you could use a silicone caulk or something. | JKCalhoun wrote: | Even backer-rod compressed between the panels would help. | jacquesm wrote: | 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. | jacquesm wrote: | 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. | [deleted] | dugmartin wrote: | 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. | JKCalhoun wrote: | I like that. It allows the interior cabin to be "open". The | Jetsons meet the Waltons. | DonHopkins wrote: | But I thought Hexagons were the Bestagons! ;) | | https://www.youtube.com/watch?v=thOifuHs6eY | | Hexagons, Pentagons, and Geodesic Domes | | http://mathtourist.blogspot.com/2010/06/hexagons-pentagons-a... | | Introduction to Hexagonal Geodesic Domes | | https://www.hexdome.com/introduction/index.php | jacknews wrote: | Not meaning to poop on anyones parade, but 'stardomes' make more | sense at this scale IMHO, http://www.stardome.jp/index-en.html | Mountain_Skies wrote: | 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. | UniverseHacker wrote: | 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. | otikik wrote: | 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. | red_trumpet wrote: | And they feature real geodesics[1]! I was a bit confused why | the geodesic dome has it's name. | | [1] https://en.wikipedia.org/wiki/Geodesic?wprov=sfla1 | el_nahual wrote: | 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 | jacknews wrote: | Except the 'stardome' has some mathematical underpinning, | rather than being just 'wattle and daub' or 'skin on frame' | for domes, etc. | justinator wrote: | 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). | XOMDOM wrote: | 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 | DOMSWOOZ wrote: | 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 | liminal wrote: | 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. | teleforce wrote: | 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. | bitxbitxbitcoin wrote: | Optimum sunlight exposure in terms of longest duration of | exposure but I don't think that would be the optimum in terms | of charge generated. | hedora wrote: | 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. | [deleted] ___________________________________________________________________ (page generated 2022-12-16 23:00 UTC)