Research and development

Exhibiting my tensegrity sculptures on the Arts Market in Fitzroy turned into an interesting experience, another opportunity to learn to fail with grace. Christian placed me between a woman selling rings and pendants made of molten glass and a soon to be physiotherapist who enjoys designing his own apparel.

My car was packed with masses of sculptures lying on each other, I was surprised that nothing got entangled and only two towers disintegrated beyond immediate repair. After I met with Christian, I carried the display boxes to my little square, and started carrying a selection of my sculptures over.

My first stall appeared in a rather raw style - I want to cover the boxes the next time, and without any price tags the commercial availability wasn't too apparent. All in all, the display was a bit overloaded as well, not too mention the fact that the wind toppled some of the towers over in regular intervals.

There weren't too many visitors on this Mother's day, so I had plenty of opportunities to chat with my neighbours. I hope that a little bit more investment to display my tensegrities better is needed, and I think I just found my entry level product - a collapsible icosahedron.

A name can help as well - Alexander Tensegrities, Can touch this!, Lenny Golightly... Would be good to find a muse to come up with a name.

Explosion of shapes

Showing the photos around to have a selection for the arts market application motivated me to build some more. And I noticed how useful especially the repetitive parts of the building process turn out for my Alexander study.

I found my preferred strut material for now, and got plenty of this as well as variations, so whenever I feel like working a new shape out I can go ahead. Well, I avoid the noisy bits during night time, that's when I can sit back, explore the different aches in various parts of my body, and reflect my experiences.

42 unfinished

I built my first structures using an online 3d animation for tensegrity objects, and there were still some objects that challenged me to handle with my own hands. I watched the animation of an octahedron unfolding into a tensegrity structure over and over, planning the stages of construction for an object with 12 struts.

Cutting the cord to length and knotting into loops and tendons posed the monotonous challenge before getting the octahedron together. I started ambitiously using elastic cord at first, but after some accidents changed over to nylon. An octahedron has six corners, which open into squares for the tensegrity. 12 tendons pull along the original vertexes. A zigzag line of force connects the opposing corners of opposing squares; all the squares show the same chirality.

Seeing a 3d animation on a two-dimensional monitor helps a lot, but it doesn't prevent me from mixing up left and right. It took me hours to develop a decent build strategy that worked without additional hands (i used some small clamps, thinking about some improvement of these little helpers).

The puzzle consists of 12 struts, 12 strings with knots at their ends as tendons, 6 strings knotted into a loop for the corner squares. Starting with the 'bottom' square, four struts connects in a clockwise (or counter-clockwise, if you wish so) to all squares but the opposing square. The struts coming from the 'bottom' and from the 'top' make up the 'left' and 'right' corners of the 'middle' row of squares, which are laterally connected with struts coming from 'bottom' of one square to the top of the adjacent square. All struts join their square with the same chirality. Simple, innit?

42 unfinished lying

Although I don't plan to rebuild '42' at any later stage, I salvaged this accidental creation later with some additional tendons. I guess my difficulties to build this structure at all might relate to the 'technical' error in its construction. 42 has 4 clockwise squares and 2 two counterclockwise squares. When pushed on the left turning corners, the structure nicely compresses, but there's little resistance when other corners get pushed in, all in all it resembles rather an egg than any Platonian Solid.

It took me late into the night to have the sculpture together, and I needed to re-attach some of the tendon to prevent struts from touching. Still, when no strut touched each other anymore, it still looked and behaved somehow wrong. The next day I noticed the mixed chirality, and yet another day later four stabilising tendons gave it its final shape.

42

I had the puzzle nearly finished, just a minor mixup in chirality, so it shouldn't be a problem to do it again, or so I thought. I tried to remember the successful build strategy from the night before to do a proper octahedron, yet it felt more like I repeated some of the typical mistakes of the day before. Usually sawing the grooves is the most unpleasant part of this projects, with familiar tensegrity objects I have figured working build strategies, but this time finding the right sequence took considerable time.

WIth a lot of breaks in between I finished the next miss in building an octahedron. It's not even a tensegrity, some of the struts touch, and its easy to tune into a floppy shape. I wonder whether to keep it, or to reuse the material for the 'real' thing.

Twisted X's

WIth the current abundance of material for struts, I started preparing 20-30 at the same time, 24 were gone now for the octahedron attempts, so I prepared the next bunch. Another chance to experiment with the easiest movements for my repetitive task, and to look out for body feedback during a new task. Precision makes life so much easier- although it's not too difficult to replace a strut in a larger model, in the build phase a failed component usually means back to the start.

At least I still I had an idea how to build this structure now, had analysed some of my prior mishaps, and started to understand more of the dynamics of the octahedron. I found a sequence for connecting struts and strings that needs only little external support and can take a bit of handling without disintegrating, cutting and knotting strings to well-known length happened nearly by itself.

Anti-Octa (counterclockwise stellated octahedron)

The third object with 12 struts, 12 tendons and 6 loops finally turned out as octahedron. Strike! Like with my first attempts with the x-module, I persisted through a series of failures until found a decent way of building. Connecting the tendons the right way meant as well that the structure started stabilizing itself to a certain degree before it was finished. Now I've got another model that can do with rough handling, the symmetry distributes impact easily, as an accidental 2 metre drop proved.

Once I connected struts and strings in the way I wanted to in order to build an octahedron, I had a better understanding about the difficulties of this process. The right sequence provided relative ease, so I wanted to do it again. I checked the clock before I prepared the strings, I still had enough struts, carefully studied Anti-Octa to build the clockwise turning equivalent.

Counterclockwise and clockwise stellated octahedrons

After 50 minutes without great difficulties the sculpture was finished. Another beast tamed. Left and right turning octa's connect nicely in the triangles created by three parallel struts. When I get bored I might be tempted to build a high-riser, although I surely need some extra tendons for vertical stability.

Different turning octahedron joined at a triangular face

I felt ready for the next challenge, using the experiences gained to tackle the cube. I had a first go just after I finished 42, but settled for building a real octahedron first before moving to the next structure. The cube has eight corner, that span into triangles for the tensegrity, and 12 connecting tendons. The model needed a bit of tuning, but this time I succeeded with the first attempt.

Even as tensegrity the inherent instability of the cubic shape becomes apparent. I might be able to balance it on one corner, which is much easier with an octahedron. However, it offers ample space in its center and looks very airy even when sitting on four corners.

Slice o'Dice (Stellated Cube)

12 struts seemed no longer a challenge, two new shapes belong now to my tensegrity alphabet, So why not have a go at the trigonal prism? Six triangular loops connecting nine strut and 9 tendons. I solved this puzzle as well on the first go. I averaged a bit the tendon length. The model doesn't balance on all corners, yet provides a wide basis when placed on three corners (for a beam). Now I need to make up my mind whether to go metal or bigger, hanging some of the structures on a string provides some good stability test and maybe some durabilty test as well.

69 (Trigonal prism, balanced on one corner)

intermezzo

As it feels like a bit of SAD is looming, I started considering marketing my tensegrity hobby a bit more, got myself busy building more models and taking some photos. First step will be to get accepted for a stall at an arts market, and then I hope hours of haggling will follow. Naming the sculptures provided quite some fun, let's see what happens next.

Concept X (Simple X-module)

Scarab (Icosahedron with two two tensuls)

Scarab

Crossed Over

North Tower (Three tensuls)

South Tower (Three tensuls)

Evil Twins (Two joined stellated tetrahedrons)

Spherical Hysterical (Thirty strut frequency 2 sphere)

Hope (stellated tetrahedron)

Amarita (stellated tetrahedron)

Victory

Peghead (Tensul joined with icosahedron)

(

21st Century (stellated tetrahedron with kite frame joined)

Monsternsegrity (5 X-modules held up by two tensuls)

More tensegrity

Before I muster the task to relate tensegrity to AT, I continue with some experiences I made while building this airy structures. Iron hooks on dowels offer plenty of constructive freedom, as well as the opportunity to install additional tendons in tower structures easily, however, with strut lengths between 15 and 30 cm they seem like an overkill.

To cut down on material costs, and for aesthetic reasons, I switched to grooved bamboo skewers. It's possible to saw a groove even in 3mm skewers, however, it seems like 10 to 15 cm is the maximal length to build solid models. Otherwise the tendons can easier tear the groove apart, or bend the skewer.

Building an icosahedron with 6 struts comes relatively easy, at least with elastic cord which isn't too tense. The stellated tetrahedron (or Snelson tetrahedron) is a bit more challenging. The photo above shows my first approach, fixing three strut ends with a rubber band into their corner of the tetrahedron, attaching the corner triangles, the connecting tendons, and finally, cutting the rubber bands to 'explode' the structure into shape.



The photo above shows a stellated tetrahedron (secured with tape instead of rubber bands), just before it gets liberated from struts forced into touching. Although I deployed this method plenty of times, it felt a bit cumbersome and wasteful to me (tape needs to be really tight to withstand the increasing (over) tension of the model, and many rubber bands were cut and later found in unexpected places).

While playing with different tower constellations, I noticed the nice compatibility between the triangular faces of the stellated tetrahedron and tensuls (minimal tensegrity structures). The 6-level tower I used for my presentation uses stellated tetras as base and top, connected by four tensuls in line. In a Snelson tetrahedron, each corner has the same chirality, I'm quite sure though that I managed to build stable structures with at least one corner out of sync. The corner fixing method does not prevent having the beams meet in the wrong order, elastic cord saved me from starting over from scratch many times.

What if I started with a skewed tensul (small base, large top loop) and extended it to a stellated tetrahedron?


I used nylon (orange) for the surplus connections, and elastic cord for the final structure. Placed on one tip, three struts touch the ground, and three float freely. The end of each ground-touching strut is part of the remaining three corner triangles, so I threaded the elastic cord underneath the nylon cord that secured the temporary tensul. The choice of materials made my life easier - the elastic cords wedged nicely into the grooves without slipping out by themselves (or gravity, or clumsiness on my side).



The tensul provided enough stability to connect the floating beams easily. I had ample opportunity to check that all corners had the same chirality, and then decided to turn the structure around to attach the final tendons. I had to unhook the tensul tendons, which turned out quite easy. The final three tendons had to go underneath the tensul tendons and top triangle. This was a bit more fiddly, yet I encountered no total collapse with the need to start over.



Inspired by the ease of constructing a formerly hard to tackle structure I prepared more struts for the same structure with opposite chirality throughout. Sawing six skewers to size and cutting twelve grooves is the 'mind-numbing' aspect, a great opportunity to stay directed. Precision is a key to tensegrity structures, although there is also a bit room for improvisation. The small diameter makes precision inevitable - having a structure collapse due to a badly crafted groove is not on my list of goals.

I made a game out of the 'boring' part, asking for a 'creamy' quality of the hand guiding the Dremel tool. Although I still appreciate having spare material around, I seem to mess up less and less material. I begin to trust more the inherent qualities of tensegrity models. For one thing, tossing them around accidentally hardly ever decomposed them, and it's straight forward to replace single tendons after the build is complete.

I decided to make my two stellated bamboo tetrahedrons a combination of nylon and elastic cord. Not only do they have opposing chirality, one has elastic triangles, the other elastic tendons, and nylon for the other tension element.



Building this models felt fast and simple, yet there might be a further improvement: If tendons and tension loops have different colours, it's easy to pre-thread all connections underneath the temporary tensul tendons, which then can be simply lifted off once everything is in place.

I didn't stop there, though. With enough material, time and obsession at my hands I started researching the web and came across Snelsons X-module. The photos provided me with an idea how to construct this structure, and another remarkable site offers a java applet that helps finding the lengths for all the tendons.

The Snelson model has only one central tendon (which certainly works with fixed tendon lengths and heavy struts), yet two tendons offer more stability when moved around, and don't depend on gravity and the ground to provide a second tension vector.



Colour the different cord lengths made the assembly a piece of cake, checking the cord lengths after knotting them was my quality assurance measure. The need for a second central tendon was already apparent when I built the above model. Depending on the relation of cord lengths and the viewing angle, the name 'x-module' becomes very obvious.



After finishing the first x-module, I noticed to my surprise that I rebuild a structure that puzzled me for some days when I built it first. On of the 'ugliest' model still remaining in my collection is a 4 strut tensegrity, and I rather kept it as 3d model if I ever wanted to recreate it than for any spectator value. When I started building the X-module, I had no idea that I would end up with something familiar, another indication how confusing it sometimes is to imagine all aspects of a 3d tensegrity structure from photos.

The second surprise belongs to the structural category. You have, more or less, two pairs of x-shaped beams perpendicular to each other. WIth only the tendon shown in the photos for Snelson's structure, my model stayed quite flat. Attaching the second tendon moved the entire structure perpendicular to this tendon. I wonder how this affects a series of connected x-modules, I found some plans for a tower, yet I haven't managed to decode the cord lengths info I need.

After exploring different 'base' moduls - tensuls, stellated tetrahedron, x-module, icosahedron - I get more curious about towers. Craig still recalls my visual demonstration of 'any part affects/reverberates throughout the entire structure', and I want to have some more video of tensegrities in motion. Building a x-module tower looks like an interesting challenge, I hope my trustworthy bamboo won't break under the load.

Tensegrity

David offered me the opportunity to do my tensegrity workshop during our school's residential. This meant that my car was heavily loaded with plenty of light objects, sensory overload by having a variety of models was part of my plan.

I got so much used to have tensegrity models in my lounge that I nearly forgot the awe they inspire quite often on first sight. Martin hardly couldn't keep his hands off them while driving to Maitripa, and I knew that the strategy of using them as attention grabber would make the presentation part much easier.

I arranged plenty of the smaller and simpler models on the table next to the stage area, the tower and the larger sphere standing next to me. The mind map I made half a year ago laid on a table close by as well, yet I think I used it only a couple of times.



I wasn't tempted to rehearse the presentation, yet I took the chance to work in front of the group with Michael Shellshear on my nervousness about it. He helped me defining a clear goal, and suggested to have a clear beginning, middle part and end for the presentation. Finding a SMART goal wasn't easy, tensegrity offers so many ideas and connections to the work, and of course, eagerly end-gaining as I can be, I wanted to put a lot information into the workshop.

My idea was it to give the participants a more embodied understanding of tensegrity, and to learn more about the qualities of such systems in general. Yet Michael steered me into finding a single quality as focus - bounciness. I'm pretty sure he set some anchors when working with me, although I couldn't consciously describe them.



I started off with a short explanation of the origin of the term, letting my admiration for Buckminster Fuller shining through. I used the metaphor 'island of compression in a sea of tension' to describe the discontinuity of compression (we're no stack of bricks, although some people's thinking is sometimes as flexible as one).

I used to model with a similar structure, but with different tension material (rubber, ie very flexible and nylon ie very tense) to give the participants the first opportunity to play. The models nicely demonstrate expansion and contraction in all dimensions, and squeezing and pulling made the difference in mobility depending on the pretension level (golgi, I hear ya calling) obvious.

I felt quite calm and collected, the adrenaline didn't throw me off but kept me moving confidently. Before I could lose the interest of my audience by the technicalities of the minimal tensegrity system (tensul), making pauses in the verbal part allowed questions, so I could navigate along the mindmap in response to my audience.

The fun started for me when I explained the teamwork task, the 'middle' part of the workshop. I demonstrated the total collapse of a tensul from a box shape into a hodge podge of strings and sticks, and asked the participants to do the same with the models I handed them before.

I had no idea how long it would take the groups to get the models back together, I still consider even a tensul quite a challenging 3d puzzle. I could kick back a bit, observe the attempts of rebuilding with plenty of space to offer help and answer questions. The first team to succeed were Rossi and Jenny, proudly claiming to have won this friendly 'competition'. Yet, instead of simply bragging about this victory they continued to explore kinestically their little toys, while the other teams by and by caught up.

In the two presentations I held no team failed in the end, although some needed to start over a couple of times (you can connect the materials I gave them to a boxy shape which isn't a real tensul). The task kept the participants engaged and interested, and the success yielded many smiles of accomplishment.

This made it easy to get to end part of the workshop. Playing with the tensuls brought up some questions, and offered me the chance to relate the tensegrity idea to anatomy and AT work. Well, I might have stressed the similarities I suspect a bit more, but I guess I will do this workshop again. The questions were interesting, and especially the demonstrations with the shroom-tower model seems to work very well.

I took Carina's suggestion to ask everyone for a single bit they learned in that workshop, and noticed that I achieved my goal - transforming the term 'tensegrity' from a learned-sounding expression to a more lively concept.

However, in retrospect areas for improvement become more apparent. Bounciness, the initial goal, was left out a bit. I realised at home that some of models can be thrown around quite a bit without falling apart, I might use a sphere model for some contact juggling like acts, with some deliberate drops to show the bounce. Now I need to find a good backdrop to shoot some videos of models in movement (the hall I held the workshop with its beautiful Buddha statue would have been ace for that).

Luckily Ana took the photos you can see here, pictures can often tell so much more than words.

Proof of concept

If I had to earn money with some of my leisure time projects, I certainly would need to learn to do better estimates of the time involved. About a week after I prepared all the struts needed for my first geodesic dome, I dared to attempt another proof of concept.

I spend about two hours to make sure that each and every strut retains in the connector, gaffer taping the ends to prevent slipping. I hoped that as long as the structure remained connected, I could assemble it entirely. To my surprise, it worked out well, just the idea to document the build failed.



Next time, I rather trust that I hardly notice the camera working on a minute interval. After 14 minutes I wondered whether the camera worked as desired, and stopped the sequence incidentally... however, it took me somewhere between 30 and 45 minutes to get the structure up, and about 20 minutes to deconstruct the frame again.

Although the hose connectors don't stabilise the structure much during assembly, once everything is in place it feels quite sturdy. I could carry the structure around easily, but I certainly have to skip the idea of decent door opening. If it becomes a shelter, I rather climb through a lower triangle than endangering structural integrity.

Pegging down, probably already at a very early state, might be a good idea as well. I wish a had a tarp around, or better some house wrap, to test the integrity with a bit of wind and a skin. The surface area doesn't seem to big, though I want to have quite a snug cover, repeating the shape of the frame. I can't really say whether I want to trust it even with skin as a shelter, but I'm more than curious to cover it decently.

While I managed to do my directions in some of the various dull stages of this project, I happily forgot about directing today. Yet all the crawling around, squatting and bending has left no pain, the only thing I notice is more exposure to midday sun. Any dome project will offer plenty of opportunity to apply the technique - heaps of repetitive tasks, most of them unfamiliar, so there's heap of opportunity to stop and reason about the means-whereby.

That doesn't in any way mean that I spend much time thinking about the means. It's hard to tell how much end-gaining was involved - I remember being calm and collected most of the time, having time for a chat with a curious passer-by. I felt primed for success, with the absence of real set-backs (two rods slipped out before during the assembly of the final pentagon) not too much exhilaration did express.

I enjoyed some minutes sitting in the shade of the tree in the middle of some sacred geometry I materialised in my neighborhood. Without a skin, a dome provides a space that seems sheltered and open at the same time. an amazing experience.



I couldn't really stand up in it, the apex was about 165 cms (rough estimation, not measured), which means that in 2v dome the radius approximates the height quite well. So as long as I don't tackle the stability problem (or the strut length), it's rather a personal shelter than a communal space.

The next challenge is finding some clever material for the skin and testing the stability under wind... Still haven't found a shop that sells Tyvek, and shelling out $90 for some other house wrap doesn't tempt me yet. I need about 30 sqm's for the skin and ground cloth, with about 10% waste included.

It has been an amazing adventure so far. From building smaller models to go large-scale, dealing with all the set-backs on the way, finding flaws and eliminating them. I know it's still a long way into my own dome home, yet it's feasible.

Taming the beast

One peculiar thing about Alexander Technique you cannot 'do' it. Do whatever you like. When you observe yourself in doing, apply the means-whereby while doing, you're using the skills Alexander Technique teaches.

However, having an excellent MacDonald style teacher in the school can look a bit like one can 'do the technique'. Nili's directions are precise and efficient, and we went through a lot of 'traditional' approaches like chair work, table work, hands on the back of a chair, monkey, lunge and finally the whispered aah.

Just watching Nili made it easy to give myself directions and keep myself up, the increased amount of 'uptime' might have led to the bit of discomfort between my shoulder blades. Or maybe just my bad use while taming a beast, namely a biggish tensegrity sphere.

I found in a cheap shop decorative bamboo struts with a nice dark red colour, together with some Sisal garden string. I build a lot of 6-strut symmetrical tensegrities lately, with a variety of connection methods and tension elements, so I started off with 50 cm rods and about 120 cm string. Sawing the grooves with the Dremel becomes more and more routine, although I find myself often crouched over the work piece.

I experimented with tying the strings to the rod, and making loops with knots to slide the ends through. This would save me sawing 60 grooves into the 30 elements, for the prize of 120 knots. A lot of repetitive activity, a great challenge to consider how to do it easiest. I was eager enough to prepare all elements before the assembly, a strategy I changed soon.

Some of the loops were too big, there wasn't enough tension on the strings, and the ends could slide around. The beautiful idea of easy reusability didn't work out. Back to grooves. The next attempt used sisal strings, but as some of it ripped too easy under tension I went back to nylon line.

I cut the strings so that they had nearly no slack - this might work with more elastic strings, but after about 15 struts it became obvious that it rather break than bend into a sphere. As there is no way of lengthening too short strings, the next set of strings needed preparing. To break the monotony of preparing everything at once, I prepared 5 struts at a time (there's six building stages requiring each time 5 struts).

The first two attempts were still too long, and I waited a day without doing anything before I went with the final approach. The water balloons I used to prevent the strings from sliding were easier to attach than the rubber ring wrapping I used most of time. Unfortunately, they came as easily of again.

The youtube video that inspired me in first place shows an assembly within about five minutes. I spend already the third afternoon and still wasn't sure if everything would fall into place. As the waterballoon failed as security, I looped the string once around the strut before using a rubber band wrapper. I must have started building a sphere at least a dozen times, I know now how to connect the elements with maybe referring to one of the models. I wouldn't be surprised to rediscover the build pattern as weaving pattern.

The skewer model gained stability after stage 4, it get itself balanced on five struts as dome. I got fairly confident when I managed to move the model from its gymball 'mould' onto its own feet. The sculpture rolled in elliptical shape on the floor, I leaned with my body against it to attach the remaining struts. I assembled the final five struts as a pentagon, and carefully slid it into the still wobbly dome.




The pentagon needed 10 connections, after attaching half of them I could turn the model around and do the last connections. I even dared to leave them unsecured. The model flattened still a bit, so I removed some of rubber wrappers and looped previously unlooped connections, decreasing the overall string length slightly thus increasing the tension.

I wouldn't roll it downhill now, but it hangs nicely on a single hook on the wall. Tuning was fairly easy, so I might remove the remaining security rubbers for an overall fine tuning. For now, I rather keep it untouched for some time to see whether it tends to undo itself.

That's it, that's it!

For the next two weeks Nili Bassan visits our school, but I had a good chance to apply the technique even before then. Last night my world map fell off the wall, taking down no less than five tensegrity sculptures with it. Naturally, or so it seems, my latest project, a 30-strut sphere, unfolded again.

So I exercised patience, delayed my desire for a quick fix, and went to school. The turn with Jenny eased me a lot, and her idea to feel amused rather than irrated by the asymmetrical way of using my body helped with this a lot.

The hands-on group with Jenny offered more interesting experiences. I worked with Alysha, and surprised myself by a mixture of old doing habits and some surprisingly effective directing.

In Nili's group I partnered up with Jane Azul, continuing basically where we left off with Jenny. I got quite nervous when Nili came to work with us, however, I picked up some valuable information of some of the 'extra' I put in when putting hands on.

Spherical hysterical

The transformation from sticks and strings into three dimensional structures still stuns me. And provides me with ample opportunity to learn about my end-gaining tendencies.

Producing the elements required to build this airy structures meant that I had to some repetitive activities with a specific target in mind: precision. I noticed that especially the flexibility of the tension elements provides some leeway for the measurements, having quite uniform elements simply eases construction.



With a closer look you can see rubber band along the compression elements, I used those to prevent the nylon string from slipping out of the grooves. The model was quite sturdy yet bouncy, and I decided to take the 'safety rubber' off. At some point my ambitions backfired, and sphere flattened into a sheet. Bummer.

The construction of the sphere was quite straight forward, but I realised that not all the grooves were narrow enough to hold the string in place, I delayed the next construction attempt until better tools arrived.

It took only a week until a set of diamond blades arrived, and instead of using 6mm wooden dowels I took some large bamboo skewers. Again, I had to manufacture more than 30 identical elements to build my sphere, this time using transparent elastic string as tension element.



It took two or three attempts, and a bowl to provide some initial curvature to build this model, and this time it remained stable after removing any rubber band used to prevent slipping. It even survived inserting a balloon on the inside, to provide some more photographic attraction.

The balloon decided its fate. I build a small tensegrity base for the sphere, and took some photos on the outside, utilizing sunlight.



Slight gusts were sufficient to get the sphere rolling off its base, and I when placed the sculpure in front of the next backdrop a gust dropped it to the pavement, where it collapsed. Well, I got it together once, and I already have the next idea how to tackle my string slipping out of groove problem can be handled. At least, I got into the habit of taking photos of the finishing stages of my tensegrity before I do further experiments or 'improvements' with them.

Rubberband man

Nearly 5 metres of wooden dowel were waiting to be transformed, for weeks. I wanted to build to tensegrity sphere, as precursor for a model of an eye. I found a great demonstration how to do this, yet it meant a departure from my prior ways of attaching the tension elements.

Many small models made of units that combine a tensile and compressive element, which basically offers a bit more flexibility than the 'tension loops' I used before. The loops, on the other hands, reflect some of the 'Great circles' created by rotation.

Like so often, I departed a bit from the original measurements, using thicker dowels makes the sphere less 'airy' than the model in the youtube video. The biggest challenge was precision this time, I had to saw a groove to hold the string at both ends of the dowels.

Using my new Dremel, I went through some cutting blades, luckily wearing goggles that saved me from the first violently disintegrating blade. I still haven't got the proper gizmo for wood cutting, and the different blades I used produced different wide and deep grooves. Also, I didn't glue the strings to the dowels, so some became easily undone.

My first attempts to assemble the sphere failed badly. Most grooves were so wide that the strings slipped out easily, so after some frustrating trials I called it a day. I had made 32 elements (the sphere needs 30), and wondered if I could use them for something, at the same time thinking about simple solutions to overcome the slipperyness.

Again, rubber bands saved my day. The models I build with them deteriorate quite fast, but as temporary solution they worked wonders. I secured each connection between the units with a rubber band, and, voila, I could follow the demonstration video nearly step by step to success. Unfortunately, this went much faster than my camera batteries recharged. Before I'm brave enough to see whether the sphere will survive without any rubber bands, I'll wait to document the first bouncy bit.

More tensegrity

School started again with 15 minutes quick-ease, walking into the hands of teachers and older students to get some up on the fly. I worked with Jenny on staying more present throughout my body, but I still can't easily let go of expectations.

The book discussion veered a bit off, without getting too excited. Each of us has an idiosyncratic understanding of Alexander owns writings, which seem to reflect a bit in which phase of the process we are.

I enjoyed the hands-on sessions a lot, although I still don't register too much with my hands. I stand less in my way, though, and my arms certainly move lots easier than during my first explorations. I noticed in Libby's group how much I got used to a specific relation of my hands, playing around with different ways gave me plenty of new insights.

At home, I stumbled across a new idea for a sculpture, a tensegrity icosahedron. It is symmetrical, and stackable (I will have to try this for myself....). I found different examples on the web, and experimented with different methods to assemble the structure. I started off with rubber bands in a variety of configurations, and lots of them got destroyed in the process. At some point it looked like I succeeded...



I managed to tune the model to give it more depth, and nearly collapsed it in the process. I fixed it, and thought about the right length for nylon cords. I had to take care not too overstretch any rubber, which happened just two or three times.



After experimenting with 40cm and 50cm loops, having models collapsing over and over, I prepared 45cm loops, got some unused rubber rings and started over again. Once all nylon cords were attached, I cut the rubber away, and, hooray!, I had a stable model in my hands!



I wanted to stand the model on only two legs, and used magnetic repulsion to keep it balanced. It can swing a few millimeters, blowing against the struts suffices to get it moving for just under a minute or so.