I am thinking about building Geo-Domes in the MakerSpace. Here is an update on the current state:

calculator: 2V 1/2 Geodome Calculator | Geodome Shelter Systems

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roughly 5m diameter geodome

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roughtly 4m

30x 1.093m

35x 1.236m

cut: 1.093 + 1.093 + 1.236 + 1.236 + 1.236 = 5.894

→ 13 6m pieces

→ cost:

Hi Nicco, this may be of help: Proctor's Wheelwright machinery, part 1, Sovereign Hill, making wagon wheel parts - YouTube

This is a traditional design, which we can modernise and automate for production and flexibility.

ATB, Dom

Hi Dom, thanks for letting me know. I already think about the angles and how to change them. They stay the same and are in the geodome calculator. Trying out email reply here.

@Davidj I am wondering about the steel pipes for the geo dome and which of them are alright to use. If we can have a look at these so I know which ones are ok to use, that would be much appreciated.

Personally, I would go for the easy connectors from the photos I made up there. I am a bit hesitant to drill holes into the pipes at the same place that they are connected to the corner connector because that is the place in which they face the most tension. Since it might be steel, this might not be an issue - still it weakens the structure.

Diameters for the connector pipe:

I have ordered the aluminium pipes and they have arrived.

**19mm x 1.6mm ( 3/4" OD x 16swg ) Aluminium Tube**

I needed 13 of them 6m long ones. The cost: £182.83

I would like to make the connectors first.

How to compute the length:

Sizes:

- s - short pipe is 1 unit - 30 needed
- l - long pipe is 1.131 units - 35 needed
- c - lost by cutting (fix but unknown)
- M - the width of the middle of a connector = 1/2 the distance of a pipe to the middle of the connector = added length to a pipe for the whole geo dome

Cuts:

- s + s + l + l + l + c = 6m | 9 times
- s + s + s + l + l + c < 6m | 4 times

13 pipes a 6m

Counts:

- I:
**30 = 2xC1 + 3xC2** (short)
- II:
**35 = 3xC1 + 2xC2** (long)
- 3
*I - 2*II: 90 - 70 = 6*C1 + 9*C2 - 6*C1 - 4*C2 = 20 = 5*C2 => C2=4

Sizes:

- I:
**s + M = u**
- II:
**l + M = 1.131u**
- III:
**2s + 3l + c = 6m**
- IV: l + M = 1.131s + 1.131M | II substitute u from I
- V: s = 3m - .5c - 1.5l | from III
- VI: l + M = 1.131x3m - 1.131x.5c - 1.131x1.5xl + 1.131M | IV substitute s from V

= 3.393m - 0.5655c - 1.6965l + 1.131M
- VII: l = 3.393m/2.6965 - 0.5655c/2.6965 + 0.131M/2.6965 | VI + 1.6965l, - M, /2.6965

= 1.2583m - 0.2097c + 0.0485M
- VIII: s = 3m - 0.5c - 1.5(1.2583m - 0.2097c + 0.0485M) | V substitute l

= 1,1126m - 0,18545c - 0.7275M

Lengths for M=0,022m and c=0.02m:

- s = 1.093m & l = 1.255m,
- cut: 1,255m; 2,510m; 3,603m; 4,696m;
- cut 4x: 5,789m
- cut 9x: 5,951m

Material:

M seems to be at least twice the diameter of the pipe, in this case minimum 4cm

conclusion: we look for 9cm+ straight round branches, with bark and moss a 33cm minimum circumference. We need 26 of them, min 6 cm (2+2+2)cm height.

That is min 156cm of required branch, not counting off-cut of the saw blade and eventual bends in the branch

I am making a jig - first version - to go on the pillar drill so we can rotate the geo dome connector.

I liked how the process went: every contribution removed some complexity from the initial sketch. Thanks!

See also:

Pictures from making the jig:

This is the picture I used for the angles, made with Inkscape:

https://share.ms.quelltext.eu/download/60deg,72deg-divided-circle.public.svg

More pictures since some parts are already in production (wet willow prototype)

Cutting the pipes took about 2 hours. Marking them and getting everything ready to cut 30 minutes.

The geo dome is up! Celebration!

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Here is a picture of another geo dome type: a 3V dome from scaffolding poles.