Step 4: Understanding the construction

The tensegrity structure we envisioned had never been built before to our knowledge.  At first we weren't even sure it was going to be stable, and then we weren't sure it would be viable to construct even if it was. 

I started by making models.  The first model used 3 foot long wood rods and only a small number of strings.  It was similar to a normal tensegrity shown in the photos here.  It seemed to work so then we made the 2nd model using 12 foot long wood 2x4's.  The 2nd model we strung together using standard 1/4" yacht rope with about half as many rope segments as the final.  This helped us arrive at a mathematical model of the design, and also gave us a good understanding of the construction challenges.

Our structure replaces each of the single ropes shown in the "normal" tensegrities below with an entire spline of 12 ropes.  From building the models, we learned that tensioning all the ropes equally was difficult.  We needed to build a tensioning mechanism into our structure.

In our structure, each rope starts inside a tube, goes through 2 holes in a 2nd tube and then to a tensioner at the center of the 2nd tube.  So, there are 3 holes for each rope total.

Making a model like this can be done in a couple hours, you can make a small one yourself at home!  See the last step of the project.

hey can any one help me <br>i want to do it but i cannt know how many hole i should make <br>if any one can send me a vedio around it <br>i will be happy please help me fast <br>here is my email <br>ping23479233@hotmail.com
This look cool. It took a bit for me to realize what this is. I thought it was small...<br><br>But this looks great, I just wish that there was a desktop version, even if it didnt play.
you can make your own non-musical one, no problem! all you need is 3 sticks, a spool of string, and a drill. drill 3 rows of equally spaced holes down the sticks (lets say, 3 rows of 12 holes). cut string into 9 pieces. feed the string through the holes. the models we made in step 4 are done just this way. you may need to have a 2nd person hold the 3 sticks in about the right orientation while you feed the strings through. i think i'll add this as a new step.
Hey Dan, are you still looking for a museum for the &quot;Rope and Sound Interactive Tensegrity Sculpture&quot;? I'll be emailing you at your monkeylectric email with my info. Thanks. <br> <br>Regards, <br>Lic. Robert Moreno
This thing is amazing up until the part where you change hi-rezolution naturally complex signals into midi to trigger recordings of other instruments. You should be using models for re-synthesis instead. Then it will become more like a real instrument instead of another beautiful sculpture that mimics a midi-controller from the 80's.<br><br>I might like to help with that part, if you are interested. Thank you for the great instructable!<br>
yes that would make it better. we didn't do that yet because it is much harder than for a normal stringed instrument. metal instrument strings are very good at having a predictable response that changes consistently depending on the strength and timing of the plucking. the response of our ropes varies a lot given the same input stimulus. this made it a challenge just to reliably detect that they were plucked at all.
Cool sculpture , great idea . Just one thing your sculpture is based on one of Kenneth Snelson's designs . Bucky was pretty smart and cool and all that , but he got his idea from Snelson . Really look it up . Bucky was a shameless self promoter . LOL
oh thanks, i added a link to that.<br>
Ok, I'll be the first to ask - how much did this thing cost to build? It's a nice piece of artwork, but it had to be expensive!
About $10,000 in parts and materials. Labor not included.<br>
Lol, too much $$$ for musical jump-ropes tied to a girder.<br><br>It's nice though.
i've seen lots of times where a bunch of paint smeared onto a piece of cloth costs over $1 million. i mean really!<br>
You know, you have a point there. LOL!
begs for a vid of sculpture in use w/ good sound...
Nice work, a bit out of 'iblers usual league, but nice. <br><br>Is the rope commercially available ? <br>Steve
yo uneed to do an 'ible on that sweet braider you have... <br>cool 'ible and nice art
Wozers! Talented man

About This Instructable


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Bio: Dan Goldwater is a co-founder of Instructables. Currently he operates MonkeyLectric where he develops revolutionary bike lighting products. He also writes a DIY column for ... More »
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