DIY Dome – Building a Geodesic Monodome

So I’m working on a new personal project. Vessel. I reached a point where I needed to do lots of camera tests in the dome but feedback was too slow, so a few months ago I decided to make a dome so I can really get into it. The final chapter of the film is meant to give the sensation of falling. You know, spinning in infinity, tumbling in turmoil. I know it’s possible in the dome, it’s just out of my reach unless I’m right there… in flow… In the dome… At home, with space to think and feel. Very hard to achieve in the dome straight after work. So yeah, I’ve been working on it over the past month and it’s finally a thing. A real thing.

So this is the story so far.

Research

Firstly some research. I didn’t do a lot. Actually as soon as I saw a few of the card geodesic domes that were held together with bulldog clips I knew that this was the design for me. Cardboard is cheap and easy to get hold of, and I like the idea of being able to de-construct the dome. I live in a small flat.

Here’s a mural of a bunch of the images and links I referenced. There’s a couple of good links that Max gave me for constructing a more permanent structure. A number of other interesting things also.

Design

The design was pretty simple. I made a hemispheric geosphere in 3dsMax with 2 segments… Otherwise known as a geodesic dome.

To maximise head room in the centre of the dome, which is the best viewing position, I want to position the mirror and projector in a vertical configuration rather than the standard horizontal position. I’m not sure if there will be any resolution benefits from this in the sweet spot but this is something I want to test also. I’m also not really sure how to rig this all up and keep it modifiable. I’m hoping that I’ll come up with something in my sleep. Looking at the image below you can see the spherical mirror placement (blue sphere section) and the projector position (represented by a camera icon).

I set the radius at 1.2 metres and measured the edges of the two different triangles that make up the whole surface of the dome. There are two types of triangles involved, equilateral and isosceles. 5 isosceles triangles make each of the 6 pentagons that are positioned to allow the equilateral triangles to fill the gaps in-between. I added a 2.5cm overlap, which folds up and can be connected to the neighbouring triangle.

Construction

I picked up a couple of cardboard boxes from Tesco’s and to begin with I just cut out a couple of cardboard triangles using a scalpel knife and a standard 30cm ruler. It took ages. 2 ply card is pretty thick so it took some slashing to get through. More robust tools were definitely required. asd

I also needed a substantial amount of cardboard. I could only get 1 triangle per box. 50 boxes meant several trips to Tesco’s were ahead. I spoke to one of the ladies at Tesco’s and she helped me out massively, getting the produce team saving 2 ply banana boxes. High Five Tesco’s.

The next visit to Tesco’s yielded fruitful rewards. One of the guys from the produce section sorted me out with a myriad of boxes they’d saved. He brought them all out on a huge trolley and helped me flatten then down and load them into my car. He also gave me some tips on where to get some bigger and better cardboard from a factory near to where I live. Joshwin Ramji… Absolute LORD!

I borrowed an aluminium straight edge from me Dad and a proper Stanley knife off Max and got to work on the cardboard triangle factory line. I got the time down dramatically once I got into the swing of it.

Here’s the two paper templates I used to mark out the two triangles on card.

The lines around the outer edge are to be cut through completely. The dashed internal marks are actually the edges of the triangles that will form the interior surface. These lines are just scored rather than cut all the way through. This allows the card to fold.

Oh, good fortune struck again as me and Ian were walking home after work and we came across a couple of guys trying to cram a LOAD of double ply card into the back of a van. I asked if I could take some and they were more than happy for me to take what I needed. It was in much bigger sections as well which meant I could maximise the area used by tiling the template and increase efficiency by cutting along a common edge.

To fasten the cardboard triangles together I’m using bulldog clips. The clips are pretty cheap at 80p for a box of 20 from Wilkinson’s. I needed just over a hundred clips all together. They hold it together pretty well. A couple have flicked off when moving it around but generally they’re pretty solid.

Something I really didn’t think about was how sturdy the dome would be when lifting it. Due to it’s flexible hinges it easily folds inwards when it’s lifted up. It’s really sturdy when it’s on the ground though.

So yeah. The next step will be to make a base and get the projector in there. See if it works.

Update: New follow-up post on setting the projectors up.