Designing a better dome hub 

Looks very promising. The flexibility of your design is genius. I hope it comes to fruition.

Very cool. It’ll be interesting to see how this progresses. Thank you.

This design is great! I've thought about a lot of the same drawbacks of other methods that you mention in the first part of the video and completely agree that there is a need for a product like this. The way that each wing can rotate around the strut axis in order to meet its corresponding neighbor strut's wing at the midway plane is really great. The struts being bolted to each other rather than to a separate center hub prevents unwanted shifting and the placement of the top-left wing hole down and bottom-right wing hole up puts them into alignment with each other and keeps the strut from being offset from its axis. I'll search for a producer in asia that we could work with. Again, great idea, Paul.

For temporary use in non-load bearing structures, this looks great. I worry about the shearing forces that would be exerted on the screw and bolts, so I wouldn't trust it to hold up anything living, or heavy. But as part of a temporary greenhouse or tent shelter, it'd do just fine. If I were to fabricate something like this, I'd probably go with sheet metal. It'd be like making a hinge. Cut a rectangular piece , round one side and drill a hole in the center of that round. This is the hole that bolts to other hub pieces. Other side, cut down the midline, and off to one side. Roll up the tongue, mirror half the parts so the tongue rolls the other way. Screw a pair to a beam, maybe with a washer on the head for good contact. Heck, invest in tooling, and punch the blanks out with a press.

Love this, really a great concept😎

I agree with the others who left a reaction. It looks very promising. Looking forward to further progress in this project.

Molten Aluminum cans are my first build thoughts. Thanks for sharing.

Looking forward to seeing the prototypes.

Looks promising, looking forward to being able to purchase some of these for a small proof of concept, then moving on to something larger.

Brilliant design concept.

That's sheer genius. I see no reason why this would not work as you intend. You're right, it would be great to have universal hubs with more strength than what's available now. I hope you can make prototypes and test it!

Brilliant design

Ingenious. While you mentioned it, what you did not show clearly is that each hub section is in two conical sections, with 'ears'. I would suggest having interlocking teeth between the two conical surfaces to prevent it from rotating once attached to the strut. You could also make the wider conical portion have a tubular section into which the strut/dowel could be inserted, with a hole in the side for inserting a screw into the strut rather than using one screw to extend through the two conical sections into the strut. You would then use a bolt going from the narrower section (top) into a thread cut into the larger (bottom) section. Alternatively, you could use a nut on the end of the bolt inside the lower section. These could also be 3-D printed using carbon-fiber filament.

Excellent!

Brilliant!

I think it best to add teeth or gears if you may. Where the upper hub and lower hub won't slip once tighten together. The bolt should be an Allen wrench bolt in order to easily tighten and loosen the bolt in a confined configuration.

I love it!

Brilliant! This is totally visionary and got me thinking outside the box. I'm thinking about how it will connect with various hollow strut materials like piping or PVC. Looking forward to your prototype. I'm in the process of building a small model as a guide to a much larger version. Hopefully get my kids involved but unlikely. Consider patenting your idea.

Exactly whant i'm looking for, hope you do or did it !!!

I am so intested yo see how this goes. I had to delay my dome building due to flooding in the area (bought your plans a while ago) and this looks like it might be a tad easier for my poor woodworking skills! Good luck!

brilliant!

I like your concept. I hope the angle locking system is strong . Keep up the great innovations.....

I only just got to see this video, and it took a while to assimilate in my head. I love a good puzzle. It seems to me that if all the bolt holes are the same angle and distance at the end of the struts, then the multiple strut assemblies will only work for identical angles of hub struts joining at each hub. With one project, a 4 frequency summary of panels looked like this. Panel data summary Area Perimeter Side 1 Side 2 Side 3 Ang13 Ang23 1.09 4.81 1.52 1.52 1.77 54.33 54.33 1.35 5.31 1.77 1.77 1.77 59.92 59.92 1.42 5.44 1.77 1.79 1.88 58.80 57.53 1.56 5.70 1.88 1.88 1.95 58.72 58.72 1.65 5.85 1.95 1.95 1.95 60.00 60.00 .. so we have angles between 54.33 degrees and 60 degrees etc Michael Sowdal mentioned that the conical shape was going to require special casting or tooling, which makes sense. When you think about it, if you abandon the need to get the end of the struts close together, what you have here is a big hinge, with a hinge pin and two "flaps" at the end of each hub. In fact, if you abandon the idea of the end screw to hold the components together, and just have a rod projecting from the end of each strut, the two "ears" are just the opposite sides of a hinge. Its been a while since I fiddled with domes, so I may be missing something. I'll do a bit of a drawing over the next 24 hours to clarify my thoughts a bit.

very good design

I find this a great design. I hope we can see this as a finish product availablein ebay soon

Nice design looks like it will be a hub for a flat plane intersection, but I guess you could get some "dish" via flex or distortion if needed. Seems ok for non heavy duty applications or low wind areas.

Very nice design...!! Since the transfer of load from Struts to the Hub is thru that one screw, it could prove as a failure point... Just bumped into your video... will look for your latest developments...!!!

Your tube hub is a wonderful design and would work perfectly but the tooling to produce it would require casting or injection molding, both very expensive. I'm going to assume you intend to improve the production of a greenhouse structure rather than the construction of a dwelling. The use of tube frames has the big issue of covering the dome in a manner to seal it as the tube frame must be covered after construction unlike your current method that allows each frame to be covered individually (your current method rocks!). I propose you might work to remove the actual frame member and mold panels of polycarbonate to the required shape to allow them to be gasketed and riveted in place. While this would require a vacuum or strip heater forming process and limit the size of dome produced it would make the construction and sealing a snap. Please keep the good work coming.

Great Idea, Work, Contribution and Design Show, how to ease the Footprint of Humanity on our Host (Planet Earth).. Universal Geodesic Hub Joint..

After reading through the comments and digesting all the "coplanar" comments, I can understand the confusion. The various hub configurations at 7:50 look somewhat coplanar, but I can imagine these flexing to create dihedral angles. I can visualize the center "void" of the hub increasing/decreasing in size and the "ears" rotating axially to each other. Wouldn't these need some sort of keying/knurling/toothing to prevent undesired axial rotation of the "ears" once the proper angle has been acheived depending on dome frequency or hub angles. Any external loading may deform the dome. Depending on the friction of nut and bolt fasteners may be insufficient to prevent warping of the hub angles.

Wow, you are a hero with that ability to come up with most practical design concepts. And am in awe at your abilities to best utilize that Google Sketchup. You are like the Mark Knopfler of geodesics, lol. Most impressive. Have you considered uploading that onto the Thingiverse 3d printing based website? You probably have. I've been printing a few small dome connectors from that site just to tinker with and try to make sense of them, though admit to being dyslexic along with a parkinsons/ms variant, and math hurts my brain, lol, though would be interested in that one you just created right there. Also, a design that makes best sense for creating home additions with, such as for use with flat walls that have sliding glass doors on them. It's a matter of geometry for those segments that are meant to adapt with a flat wall surface area. And even perhaps dome additions that even can wrap around corners of square shaped housing structures. And adaptations for standard window frames that could work well being windows on domes, rather than just triangular shapes of windows to consider. Thanx for sharing your Vulcan knowledge in such a open source-based platform as this. Have a super day. \V/_ 🇨🇦

the zip tie hub is super strong.. best idea imo

May peace be with you. Design looks ok , but correct me if i am wrong ( i work 3D only in Sketchup :-) so far) , those 3D schematics you made works only if those strut elements are in straight position - flat , not angled for dome shaped structure. Design lack at least 1 joint element so that struts can make angle in relation towards this roughly looking hub. Friend recently suggested me those dome structures and since i like challenges so i am conducting little research because dome structures are rather none commercial appearance in Croatia. Friend is carpenter and have experience in many wood works and constructions. I do have like Tesla some schematics in head but Sketchup is rather something you really need to give much attention like every patents which were made, so closest to perfection is required , nothing less may pass. May peace stays with you.

Terrific idea! Am wondering where/how the joint takes load from an exterior covering considering that trusses must take their loads at joints. Was wondering if some sort of flanged or capped ring in the z dimension could provide that.

This is good design for temporary and light /without heavy load. I'm a bit concerned how strong to withhold load and aging will be the welding of ring to a semi conical base.

Best hubs are from Natural Spaces Domes. They are very strong and are engineered for up to 80 foot diameter domes.

This appears to be a good workable joint design.

Great design, I wonder how it would hold up. Have you tried doing a paper unfolded model of it? Awesome work! Very clever!

I like that. I wonder if you could use that recycled plastic sand mix? It seems fairly ridge.

I would like to add to Guillery's comment. In addition to making the units able to pivot, each unite should be attachable to a hallow pipe. PVC plumbing pipes ,even metal ones, are hallow and tend to be the most commonly used in DIY pyramid and geodesic dome construction. Screwing through the top section into the side only works if the side is a solid soft enough for the screw to get a firm "bite" into it.

At 9:20 you describe using pipes, but I don’t understand what you would be screwing the flanges into if the pipe is hollow. I’m building a 5/9 3V dome out of aluminum and am struggling to find a suitable hub solution for the reclaimed 26.5mm tubes. 3D printing seems like best bet at this point

Amazing thank you so much they'll definitely make a wooden that's would fit inside PVC tube this Crew 2 security on The chew would be Allen key that's could be worked on an angle this will push the two sides out word

Interesting. What size would be useful as a test? What material? I’m inclined to cast a few in aluminum or bronze just to see where the forces go.

Cool

Could you beat/stamp/drill out two "wingnuts" as in your design from metal pipe or softened PVC ? pros: no parts at all, cons:wouldn't work for wood struts, also you'd need different stamping angles for 5-way and 6-way (then again that only means having 2 different variations if you're building domes). The device design for the stamping/pounding guides would take you a couple of minutes. The only manufactured components any builder needs are the 2 jigs, reducing supplychain exponentially. Just a thought.

I love the direction this project is going. I like that (presumably) it can be preattached to each end of a strut before constructing a dome. Some thoughts... I tried to visualise it but it's not clear to me this gives the freedom of movement needed. Can it all be angled for each strut while still allowing the holes (for the bolts) to sit flush with each other? The gap in the middle of the hub will vary. Could this add extra complexity in other areas like the parts used to cover the dome? Even for a 3-way hub I count 15 individual parts to deal with. Possible to reduce further? Could the bolts work lose over time? Eg if lots of little vibrations from wind over time.

Is the cone shape really necessary? I can envision a simple cut rectangular piece of steel with the "ear" at the end angles so that the the bolt hole is centred along the top longer edge, matching your models position. It could be laser cut, or even a jig saw for proto-typing. Then roll the long rectangle ensuring the "ear" is at a right angle. I'm picturing a door hinge, how the tubes created by the by rolling the metal are stacked with the pin going through them. You could probably cut a door hinge to just to try it out. Just a thought.

I like the simplicity of the proposed attachment, however, there is a dead space created at the centre of each junction due to the design of the attachment. In the case of a three way junction this is a reasonably small triangle, but for both the pentagonal and hexagonal junctions the dead spaces would amount to substantial pentagons and hexagons, respectively. To ensure the weather integrity of any geodesic dome created as a structure using the suggested attachment would require some suitable solution to deal with the resulting holes at each hub.

Is the same part used in all the N-way connections and dome frequency configurations?

I like it, when will it be on Kickstarter? What would the possible load be? Thinking about kids climbing...

It looks like the same principle as the wanger flange from the uk

Another idea -- what if you had triangular panels with the wingnuts integrated on the corners ? Then we'd get not only hubless but strutless.

Love the idea and concept but one flaw is the fact it’s set on a flat plane the domes angle in depending on the frequency at the joints so like a 5 frequency dome 20 foot diameter has a 6 degree angle need to make the hub pivot at bolt connections or make preset angles for each design angle but the overall design is great and would love to see this as a viable solution for connections in domes

A very nice design hub, but the screw at the top of the strut in wood is critical if it is used in some sorts of wood which are not durable.

Great thinking - only if using as a universal hub you need to be able to fix a screw in the center face of your strut. Now that is rather difficult when using metal conduit or other types of tubes. But you are the wood guy Paul - so that will be a good hub your green house uses. For larger Domes the hub should be looked at with regards to shear forces under different loads - it looks not too strong in my humble opinion, unless you cast it from steel or do a CNC milling job. So compared to the Ring and punched sheet metal (at 1:26) that you didn't like in your video it seems rather more costly to make a strong version of your more complex design that that ring hub. Also - Have you looked at the simple angle iron idea? Seems similar with the screw in the center face of your strut, but is by far less complex. There are guys selling it made from plastic for small domes. But when using a thicker metal - all you need is to drill and bend it. I guess you have looked at this as well. Let us know what you think about that design. Let's stay creative, constructive and connected - many thanks to you for your great passionate work.

What about hub cover to allow roofing materials such as 5/8 or 3/4 plywood

at 9:04 you're saying you can have any angle (which will be needed in some cases, like a 6-way hub with 2x55.7 & 4x62.2 degree angles), but I didn't get it how you achieve that? Otherwise looks great!

I like the design. One question: How do you adjust for the dihedral angle?

you could make a small 3d printed model prototype! if you could put the files (preferably step files) on thingiverse so i could print these to test them that would be great.

I saw a hub that was cut from plywood and the struts were slotted at the appropriate angle and then a wooden dowel was used to pin it together at each strut. Very large livable dome. Used 2x6 for the struts and the hubs appeared to be 3/4” plywood. A CNC router could make mince meat out of it all I would guess. Anyway, anyones thoughts are info about this sort of dome build system?

Is the angle of the cone 6.5 deg. Like with the G15 greenhouse plans that I purchased?

Did you made them finally / update / improvement?

Can you confirm that you remove the diameter (2 x radius) of the hub from the length of strut given by the calculator?

how do you attach poly carbonate or ply wood to the pipe. in the US it needs to connect a 2x4 foe a green house for building codes.

I think hub caps could be cool

So the "hub" doesn't angle and the struts need to be cut with the correct angle at the end?

I like it for its simplicity, however I think it has a fundamental limitation to scale. the connections can only be so big and I think it limits the strength to weight ratio so your not going to be using it to build any geodesic super domes. I am envious of your sketchup skills, I too have a hub design in my mind but lack the sketchup skills to make the model. My design is more robust hub that has some added features as it can be incorporated into a double geodesic dome for a super structure that could be used in concrete forming or aircrete forming.

I would agree with Mårten Woxberg. 'So the "hub" doesn't angle and the struts need to be cut with the correct angle at the end?'

Any updates on this project ? Did you get your prototypes ?

Design suggestion. Piece #1 ( top cone ) Piece #2 ( bottom cone ) create a spline(tenon) that comes off of the Bottom surface. ( think mortise and tenon attachment to the strut material) end material can be easily mortised ( jig saw, hand saw, table saw ) to receive the tenon. any material you choose to make the cones out of can be cross drilled while in the endgrain of the strut. strut owner can countersink any hardware used to attach strut to Hubcone #2 thickening the "hole" attach point to the cone...( twist minimalization ) 4:29 of the video. Where the "arm" meets the cone.maybe a triangle instead of a rectangle?(topview) also... RU-vid videos do not protect your "patent" idea.... take your design, print it, MAIL IT to yourself... while you wait on the patent to process... this is a definitive DATE Stamp that will hold up in any court.

you still into doing this? because I'm setting up a personal foundry over the winter

Put groove on inner part of hub ears that you bolt so they lock into each other after positioning them .Also those ear taps that you bolt would have to be thick for strength. COULD BE A WEAK POINT

I suggest that you try to condense this concept into a 30 second video and submit it to AvE. He is offering to mill prototypes on his new 5-axis Haas machine if people have good ideas to work with. Check out his channel, just type 'ave cnc' in the search bar.

Surely all the struts have to lie in a plane?

Hi Paul, I've designed new (I hope better & simpler) geo-dome hub connector. One that should be universal for all the angles, and also that can be made only by the most standard & commonly available steel profiles (or other materials if strong enough for the size & purpose). I made a small SketchUp project to illustrate. 3dwarehouse.sketchup.com/model/c63c616b-60b5-497a-a88a-c1cff30269f0/Universal-Geodesic-Dome-Connector There's detailed description in the project too. But here's the main idea: Around the hub of course we have either 5 or 6 struts (I prefer to use rectangular tubes since when tightened they'll fit to the other flat elements' surfaces and add some friction force. But there's no big issue to use round tubes for example, perhaps with some spacers); In the middle there's the main hub, which is basically two flat plates (steel in my case). These plates should have either 6 holes or 5 holes at needed angles - I mean general angles like the 5-way hub should have it's holes at about 72 degrees, and 6-way hub at about 60 degrees. For a v3 hub actually most of the 6-way hubs will have angles like 55.7 & 62.2 but they're close enough to 60 and the rotation that the bolts give will allow adjustment to the exact needed angle (automatically by connecting the struts with correct lengths). So no need to be super precise and drill different plates with tiny angles differences. The plates should also have some corners cut so that after the hole there's the same distance to the end of the plate - in my example I'm using M14 bolts, and leaving another 14mm of material on the plate, then cut perpendicular to the line between the plate's center and the respective hole - should be simple enough. Then there's the 'magic' :) short square profile pegs (in my sizing 30x30x90mm). They're also very common profile, just square extrusion profiles, pick the needed width cut in pieces (90mm in my case) and then drill two holes for the M14 bolts, but drill them on perpendicular sides of the peg - ie you should get something like a middle of a Cardan-Joint (or CV-Joint) one of the holes will go in between the hub plates, and the other in the end of the struts' tube. So the bolts on the plate will allow to adjust the exact angles between the struts, and the other bolt (thru each struts' end) will adjust the dihedral angles between the dome panels. This design isn't something original - actually functionally it's very similar to the one you show at 1:24, but without such custom parts or assembly. The main advantage is the simplicity - no custom parts of processing is needed - just simple cutting at certain lengths and drilling some holes. Optional) For smaller and lighter domes with lighter frames, the two plates (if thinner sheets are used) can be reinforced by adding a ring with the same thickness as the square-pegs - very much as the ring-hub design from ZipTieDomes . This should reinforce the plates against bending caused by high load and the fact that load direction is not in the same plane (ie at about 156 degrees instead of 180). The distance between the inner ends of the square pegs should determine the ring diameter. These rings can also be cut from standard (wide) pipes, nothing complex. If the struts have thinner walls laying all the weight on single bolt might try to bend the connection point of the struts (the bolts if chosen correctly can take much higher shear forces) but the ends of the struts can be reinforced by short sleeve, ideally same shape profile, just a size larger so that it can wrap around the strut end. Then more bolts can be used between the strut & the sleeve if necessary, and the single rotation-bolt would got thru the thicker total walls of the strut & sleeve - this should solve potential bending at the struts' ends without the need to use larger & thicker struts for the whole length, but just the ends. What do you think? I'll appreciate your opinion!

I work in company who is in steel industry. We can cut and bend. Can you send me a model please.

Please do another video when the product actually exists.

Useful Invention? | Geodesic Dome Joinery . Saw this and thought of you. google it almost the same idea.

hey Paul, if you're still out there I would love to talk with you and maybe even pay you for your time. if you're interested please reach out. thanks!

hi paul, i was thinking over your design. i don't know how to attach here sketchup file or images. as others noted below i kept in mind strength and locking ability. so my version is made of steel flat bar. (dome struts are straight steel pipes right angle cut).the flat bar bent around the strut - one end is a small "ear" while the other end is the long "ear". long ear to connect struts. between small and long ear tighten the screws to make fast the set position on strut. plus.google.com/u/0/collection/sxPkPF is my g+ account

Are you still working on this, pm me on Facebook Erwin Vanmassenhove... Or linkedIn.

Don't use one. Cut the struts at the right angle in the first place. No need for added cost.

not cheap not realistic everything started with a greenhouse dome so that means everything must click together with 3 sec a triangle or its not easy not fast and not cheap!!!

Oh no.%io

Wouldn't work