If you have any questions about domes use this thread to post your question. You don''t have to be a member to post a reply but you do if you want to post a new thread. So if your on the shy side post your question anonymously below and I''ll start a new thread for you.
[ Comments 26 ]
I am wanting to construct a 3 metre dome but using a smaller panel.
So I am looking for the formula to create all my struts around the 250mm in lenght.
I hope to be using a very light material 50mm thick and enclosed by aluminuum channel / angle and H section.
Hopefully this will do away with hub as the screwing of the channel to the panel will hold it all together.
The problem I have is working out the various strut sizes.
So I would appreciate some help on this if possible. thanks
For a 3m diameter x 1.5m high using 250mm struts you`d need to use quite a high frequency design, probably around 8v.
A dome like this would need 640 triangle panels and around 1000 struts, that`s an awful lot of bits :)
In comparison, a 4 frequency design would give exactly the same size dome (3m dia x 1.5m high) but with a lot less components (250 struts and 160 triangle panels).
The longest struts would be just under 500mm long.
3m dia is quite a compact size for a dome, I wonder what is to be used for?
hi there thought that your members may be interested in this software i have just found.
Hi... I've been looking all over the internet for a way to build a dome without the hub pieces (for a do-it-myself project). I'd like the wood to just come together naturally like I've seen on some other sites, from the hex and pent triangles. Will the dome calculator on this site allow for a dome to be built in this way? I've got a lot to learn about this, obviously. Many thanks. Roy
Hi Roy, look at this page, it shows how to build a dome using wooden blocks instead of metal hubs. I would suggest making a model first if you are new to dome building. Yes the dome calculator can be used to build pretty much any type of geodesic dome, just remember that the measurments are from vertex to vertex and you would need to shorten the struts to take into account hub measurments.
If this is your first dome i`d go with Pauls advice and build a few test domes before embarking on a more ambitious project like this.. unless you fancy a trial by fire :)
A panel dome is made up of seperate timber triangle frames that bolt together and is perhaps the most difficult method.
You will need to be extremely accurate when cutting the frame timbers. Work to the smallest tolerance possible..otherwise you`ll end up with huge gaps where perfectly fitting joints should be. The frame timbers will need to be machined lengthwise (on a jointer maybe) to form the correct edge connection angles (dihedral). Then you need to cut the compound angles at the end of each strut so the triangular frame fits together perfectly with the correct side lengths and vertex angles.
There are lots of ways to build a dome that will minimise stress related hairloss..this isn`t one of them :)
Whatever dome you decide to build..whether paper,hub/strut or even a panel variety, it`s always good to watch the progress.
all the best
Has anyone tried building a hub and strut geodesic framework and then used superadobe/coiled sandbags to complete the walls? I am incredibly fascinated by the simpleness of superadobe construction but the method only allows for construction of corbelled domes of limited sizes. Perhaps it is possible to use a geodesic framework to support the coiled sandbags and build true domes utilizing the superadobe method. For those not familiar with superadobe google Nader Khalili.
Great idea, I think it could work but you would need to make a thin skin geodesic dome (this would stop the bags falling in through the frame)You would of course loose the geodesic faceted look from the outside.
I'm getting ready to build a 2v timber greenhouse, 4 metres diameter or thereabouts. I want to use formed plywood hub covers for a smart look, does anyone know a small company that could make marine ply components like this?
The best I can offer is to contact a local joinery shop, most of the work could easily be done with simple machinery. If you have accurate drawings they should be able to give you a price. Got any drawings?
Thanks, I'm having some cad drawings done by a friend, will keep you posted!
If it`s 4m diameter it`ll be 2m high. Did you consider the low door height?
Yes, I'm looking at the height. I may make it slightly larger, raise it a few inches on concrete or stone blocks, then lengthen the lower level of struts a little. Door I haven't designed yet!
Sealing opening roof lights is exercising my brain- a few rubber sealing strips to look at wood be good if anyone knows a supplier.
Marine suppliers might be a good place to start. Closed cell neoprene is used on bulkhead panels etc. I`ve found it`s usually a cheaper option to increase the size of a dome than to add a kneewall to get extra door height..the materials for a kneewall can sometimes cost as much as the original dome :)
I would like to know if there is any uk suppliers or manufacturers of superadobe tubes?
I've heard of cal-earth who manufacture in the US, but I don't know of anyone in the UK. Something I don't understand about super-adobe tubing is how do you get the dirt in them? (the tube can be up to 1 mile long!)
you get a shovel and a funnel :)
or you could spend money on a motorized sandbag filler
I have been trying to think of a good design for a new no-kill animal shelter. Round seems like the perfect shape. All the pens can be located with an outside access and the middle can be a plexiglass work area for feeding and such. My question is this: will a multitude of barking be unbearable in a dome due to accoustics? It is already unbearable in a rectangle shaped room. But, wouldnt the low ceiling cause a lot of noise deflection? And possibly a dome might actually absorb some of the noise rather than intensify it? Please advise.
I think the central work area will need some extensive acoustic treatment as thats probably where the focal point will be for every sound in the dome :)
Hi, Can you explain the v (nu) and frequency in laymans terms.
you seem to be missing an FAQ etc.
I have only been reading about these domes since this afternoon, and wikipedia makes my head spin.
I see 2v 3v mentioned, but never explained for beginner.
2V, 3V, 4V, 5V all stem .. from 1V.
The 1V dome lacks any 6-way hubs (in hub-and-strut construction of the Icosahedron-based geodesic domes).
The 2V introduces them. That is, with 2V, there are intervening 6-way hubs between the 5-way hubs.
With 3V, there are more of them. With 4V, even more of them.
To quickly determine which frequency dome you're looking at, count the number of intervening 6-way hubs found between the 5-way hubs. Add one (1) to your count. That is the frequency of that dome.
So for example, a 3V dome has exactly 2 intervening 6-way hubs between any two 5-way hubs (taking the shortest route following the struts to neighboring hubs).
The photo of the kitty inside the dome with the Stanley saw in the lower right is a great photo of a 2V dome. Look for the 5-way hub in the lower left of the photo. Now track upward and to the right a bit; the neighbor hub is a 6-way hub. On the same track, keep going to the roof of this micro-dome. Find the 5-way hub there.
It was one step to go from the 5-way hub to the 6-way hub, and a 2nd step to land on another 5-way. So this is a 2V dome.
If you're going to constrain the struts to a maximum length (due to the supplier's furnished size limits for raw strut material) you can only build a dome smaller than some particular maximum.
Go up in frequency, the problem gets pushed back -- you can build much larger structures with the same length struts, because the frequency has increased.
Look at it this way: a 2V dome made of struts joined end-to-end (with some sort of sleeve, like a sectional tent pole or a telescoping painter's pole) can be made to a certain maximum size; and will take 65 struts to complete.
Now disassemble the telescoping pole into its two sections. Buy more of the same kind of pole from the supplier, and make a 3V or a 4V dome with them -- much bigger domes result. You had the same 'elements' (telescoping poles) to start with. (We'll assume the poles are strong enough for all frequencies of dome considered, which probably isn't the case).
The frequency allows you to scale up the dome size, without obtaining more telescoping sections to lengthen the individual poles that comprise a single 'strut' between 'vertices' of the dome. You just buy more poles of a definite maximum length, and up the frequency (from 2V to 3V; or from 3V to 4V) to expand the resulting dome size.
Similarly, if you wish to pack up the dome and reconstruct it off-site, a higher-frequency dome (of the same diameter at the base) packs into much shorter struts, when loading them in the back seat of your subcompact automobile. So you don't have them sticking out of windows -- they fit in the interior.
it's an on-site photo; the URL ends with 'uname=305'.
Title: Geodome hub idea
Posted on: 28/07/2009 21:46:03
Category: Construction Techniques and Tips
hi, good site very much appreciatted
I have purchased a set of GD27 plans and luckily have a friend with a kitchen building company who can cut all the struts, very accurately, on his machines. I am now researching coverings and I was wondering of anybody knows the amount of material required to cover this dome?
Has anyone had success with Poly Keder or Solar Wrap, or even with ETFE?
I also noticed a comment regarding the 3m height in relation to planning laws as the GD27 dome is 3073.65m, I wouldn't want to build it, only to have to tear it down due to planning. . . Thanks for your help.