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.

Toying with tensegrity - part 2

Please start with first part, in case you missed it.


Even though photos cannot capture the dynamics of a tensegrity model, they simply help illustrating why I got hooked on tensegrity. I managed to find a shot of the very first tensegrity tower I build, using nylon string for all cords. You can see some slack triangles, but the structure proved rigid and balanced enough to hold a juggling ball.



The limited stretch of nylon produces very rigid structures, and tuning can be quite tedious. However, when the cords have good prefabricated length, these models can easily used in groups to explore its dynamics.

The tower itself looked quite different from the model shown with the instructions, the tensuls kept their shapes instead have being shaped by the different loads on the tension elements.

Without elastic cord my tower had interesting qualities, but not the aesthetic appeal and surprising dynamic I expected. I decided to construct a 4 strut tensegrity structure next, which started an amazing learning experience. I estimated the cord length by using figure from a Java applet, and prepared what I needed. I didn't have any visual instruction how to lay out and construct this model, so I just started off, triangulated around and attached cords.

I marked the dowels so I could distiguish them, and had a way to write out the needed connections. The 4 strut model has 4 triangles and two 'diagonals'. On my first attempt to attach the second diagonal, while the model popped into three dimensions, some cord slipped off and the model collapsed into a chaos of rods and strings.

It took me roughly a day to figure out decent length for the final tension cords, and how to lay out the struts to allow them to unfold. I didn't count the amount of times I assembled and disassembled the flurry of strings and dowels, and how often I repeated the same mistakes in the process. Perseverance paid out, and I had a new structure to explore. I won't take it apart too soon, though, I'm still not too confident about rebuilding it again.



I used 30 cm length (instead of 20cm) for the 4 strut model, and used the left over struts for easy task: A simple 3 strut tensul with the same cord length for the main triangles. I had some elastic cord now (still not the right thing), yet combined nylon and stretch cord for the model. The final model appear much taller than the elements of my first tower. I placed the model next to it, and noticed that by adding 50% length to the compression element I gained twice the height.



Finally I found the material suggested for these kind models: Plastic stretch cord used for beading. Well, currently I'm waiting for a delivery of enough supply for extended experimentation. I picked up a similar material in a craft shop, unfortunately with just 0.5 mm diameter. It works okay so far, although the stretch factor does not work as expected yet.

The material makes it difficult to tune the models, and fix the cords to their attachment points. I managed to get three levels together, but the stabilizing triangles permanently flattened the lowest level. I guess I'll take more time for tuning the single tensuls, and fixings the cords more to the attachment.

I fiddled for a while with more securing triangles, and ended up with some entangled cord on one strut. Instead of trying any more to stand the model up, I took two more cords and hung the model up.



Depending on the lighting, the transparent tension cords are virtually invisible, enhancing the floatiness of the model. It reminds me of the idea of being 'skyhooked'. Funny enough, you can move lower parts of the model around without affecting the 'head', but when the head moves, the body follows...



I still have a long way to go if want to skeletal structures as tensegrity models. I wouldn't mind coming across enough model to buy them. Experiencing tensegrity helped me a lot understanding the process I started with learning the Alexander Technique.

Tuning one part of a tensegrity structure affect the tension levels throughout the entire structure. When we release a habitual holding pattern, other tensors (muscles) have to become active. A tensegrity model balances by specific patterns of pretension, more overall tension yields more rigidity. Sounds familiar?

By doing less we retune the tension elements, or rather, develop new patterns of feedback with our muscle spindles. We need to change our habitual reaction to this muscle spindle feedback, inhibiting the impulse to 'hold on' and send our head forward instead. This sounds easy, but many obstacles lurk on that path.

Depending on how one has used him/herself the tensors responsible for balance have weakened. Using them can 'feel wrong', and can cause discomfort and pain. We might not be aware that changes affect more than one area, or underestimate the importance of primary control.

Seeing, building and touching the floating elements of a tensegrity structure changed my conception of my own bones from the semi-solid stack of columns to mere floating compression elements. And I hope it will help my future student's understanding.