Rainbow Buckyball

After a quite disappointing season on the Rose Street Artists Market, I had a break to reconsider the direction I want to take my tensegrity work to. I want to increase the size of sculptures, but with only limited space available, and no marketing opportunity for bigger things it's not something very feasible at the moment.

So I came up with the idea to make my third buckyball, a truncated icosahedron requiring 90 struts, this time using 6 colours. With the two colours versions I already found out how to structure different colours, and I had at least a plan. There's 12 pentagons in the buckyball shape (which is basically the same layout as a soccer ball), and 20 hexagons. Using six colours means each hexagon can contain all colours.

I thought if I start out with the pentagons, each build in a single colour, it should work out in this way. It still turned out as some tricky puzzle, and the actual build took me as long as the preparation of all the elements.

After building the twelve pentagons, 60 struts were gone, and 5 five struts of each color left. Each hexagon in this tensegrity consists of the struts from a adjacent pentagon, and three that connect to another hexagon. I had to figure out a build algorithm that allowed the hexagons contain all colours, which took me only two attempts.

There are two pentagons of each colour, and as expected, they appear on opposite poles of the finished structure. To my surprise, the remaining five struts of the same colour form an equator, only this configuration warrants that each hexagon contains all colours. This symmetric distribution of colour doesn't continue with the hexagons, all of them seem to have a different variation in the way the colours are arranged.

While I expected to have at least two hexagons in 'rainbow configuration' (yellow, orange, red, purple, blue, green), it might not be possible to achieve this, but I really can't be bothered to reassemble this sphere, or to transform this into a mapping problem. The weight means it's best to suspend this sphere, which measures roughly 45 cm from pole to pole with 20cm struts.

Rainbow buckyball (90 struts)

Caught in the act

I have too many larger sculptures that want to be seen. As I haven't found a gallery, and carrying more than one of them around doesn't work too well, I outsourced some of them. Three of them vanished so far, two of them disintegrated, and four are currently on display in the neighbourhood.

Tet-a-tet

Installing my sculptures in the middle of the night has some trade-offs. One that I really liked vanished in less than 24 hours, without me having any chance to see it hanging in daylight. Another one hangs much closer to the branch its dangling from than I wanted, I couldn't see my progress in lifting it up and so it ended up too high for my liking.

My last attempt to install something on top of one of the wooden posts failed as well, not too mention the bruises I got in the process. As I fail to notice any illegal thing in placing tensegrities in the wild, I simply decided to use a break in rain to do my work.

I wanted to use a tetrahedron made of string within a tensegrity tetrahedron as mount point, which meant 'squaring a triangle. My rough measurements worked out okay, a tighter fit is still possible.

I admit, I used anti-stealth mode. As the winter came back with a cold spell, I wore my space jacket. Lazy as I can be, I rode with my unicycle, carrying a relatively large sculpture in front of me.

At my target, I saw a young woman contemplating on the bench next to the post. I smiled over to her, leaned my unicycle to the post to easily reach the top, and to my pleasure, my idea how to slip the string tetra above the post worked well.

Tet-a-tet a bit closer

I didn't wait for the sun to come back for better shots, did my best to adjust the sculpture as balanced as I could, and happily cycled back. I passed a group of people that had seen me before, one of them asked me: Where's your little thing? I just shrugged my shoulders, with a big smile, and another one commented: "Very Brunswick". Indeed.

I still have to have a second look in sunlight. The visibility seems fine, but the tetrahedral shape has least appeal. A square within a tensegrity square can use the same mounting technique, and might look much more stunning. I still need to make a choice about the strut length, I think 30 cm could be too small for a dramatic effect.

The great outdoors

With the formats and materials I used so far, my sculptures suit indoors much better than outdoors. Yet bamboo and nylon can withstand outdoor conditions, it just needs some more considerations.

I was a bit surprised when I brought a larger structure to the market on a rainy day. It lost considerable amount of tension, and also its delicate balance. Some similar happened when I spray painted a larger structure and left it outdoors for drying, on the next day it had gone into a dangerously floppy state.

My last experiment involved a 4-strut tensegrity, which basically could be balanced upside-down, with one strut fixed into the ground, and three struts floating in tension. The model reaches about 160 cm up, which gives me a bit of leeway for the tension. The first build felt okay, could be handled without disintegrating and lots of movement throughout.

I installed just before a rain storm broke out, with some significant winds. The next day, I found it still in place, yet the top three struts had folded down. The rain must have allowed the strings to stretch more than a healthy amount, although no connection become undone, the overall tension didn't suffice anymore.

With the strings still wet, I simply tuned the model by looping the strings in their grooves, taking care that the overall symmetry wasn't gone. Only 12 strings are needed to keep the 4 struts together, but I wished I had more than two hands while I tried to give it more sturdiness.

I sealed the top of the struts with a glue gun once I was happy with the overall tension, and gave it another go.

New life (in a mist of breath in a cold night)

The Melbourne weather brought a bit of sunshine the next morning, so I could finally hope for a shot in daylight. After straightening the structure in its base a bit, I was quite happy with the result. The visibility isn't too great, but I guess the sun will bleach the struts which currently blend into the background a bit.

I can only hope that the council won't rip it out too soon, it's along my favorite unicycling route so I have a fair chance to keep an eye on it for some longer. It's very accessible, and I rather have it taken by a flooding Merri Creek than over-eager council worker or some destructive neighbours. Time will tell.

New life (in an old Willow tree)

Filling the void

I started experimenting with combining tensegrity structures from the very start of my explorations. Most of the results used models of similar dimension and base geometry and some sort of quick and dirty approach. It took me a while, and some larger sculptures to deviate from this idea, and the initial set of combined structures had a clear defined orientation in space.

The idea of core and shell allowed me to create more complex structures which still can be placed in a variety of orientations. It also taught me experimentally that Buckminster Fuller's idea about the tetrahedron as smallest 'building block' of the universe can be demonstrated with tensegrity models.

Although I haven't attempted yet to exactly model the volumetric relations between the Platonic Solids as described in Synergetics, the 'compatibility' of all these highly symmetric structure becomes very apparent. Tetrahedra fits easily into 6-strut icosahedra, 12 strut cubes and octahedra, and 30 strut dodecahedra. Most likely also in 30 strut icosahedra (the most common tensegrity sphere), I just haven't bothered yet to build one.

Cubic merkaba

Octa Octa

Icosa Icosa

Inner strength

I got asked to build a tensegrity model that shows excitability on the outside, and has some core adding resistance against heavy loads. That's the inspiration for the Inner Strength models, both of which have already arrived in Queensland, with one unfortunately broken in transport. 

Inner Strength - Purple Heart

Inner Strength Purple Heart served as concept study for this idea. I used an already build up octahedron and experimented with ways to install an icosahedron in its centre. The most difficult part was to figure out the length for the tendons leading to the centre, they needed enough tension to withstand forces. Probably too much, one of the purple struts broke while the model was squashed by something heavy during transport.

Inner Strength Hard Core

I used the experiences from the first build to play with the variables a bit - a heavy, solid core held by low diameter struts for the octahedral shell. The weight of the core adds to overall tension on the outer shell in seemingly stabilising way, with still an amazing amount of varying movement throughout the structure.

Cube in octa

I already discovered that I didn't need struts in the centre, tetrahedron, octahedron and cube can be constructed by tendons joined at the corners. The Cube in octa is suspended from the center of the triangular faces of the octahedron, creating redundant network paths. The nylon tendons highlight that the cube was made without struts, and embed a familiar shape in a less conventional surrounding.

Copped Hypercube

Copped Hypercube was my first attempt to suspend the frame of a Platonic Solid in a small scale model. The struts of this model were recycled from a models that lost most of its tension, after being very floppy to begin with. The current emanation is extremely springy, and it seems like the cube adds resistance against total collapse, while some its edges slack off.

It's fun to build a framework entirely from string, so that it entirely depends on tension to hold its shape. I will have to upscale to find out more about the change in behaviour depending on the relation of inner and outer structure. The large scale model on display at the moment has a tiny tetrahedron in relation to its out shell, which still seems to contribute to its overall stability and movement.

Youtube

I decided to open a new account for all the tensegrity related videos I shot. As the user TouchThisTensegrity you can find slideshows, howtos and exploration of single objects on youtube. By and by, I will replace the videos in blogposts here with their new location.

It's also a good starting point to collect playlists of other tensegrity explorations. Hope you'll enjoy the new channel.

Changed market dates

I can't come to the market on June 24th. I will figure out next sunday which alternative date I pick, and what to do in the next market season. However, I found a new way to relatively safely send models via mail, so your last chance to obtain one of my wonderfully weird works hasn't come yet.