Why there's more to Tensegrity than 'Impossible Tables' 

I've got an experimental robot concept coming up next week, but I'd like to use Tensegrity in the future for something mechanical. Patrons and RU-vid Channel Members have next week's video already!

Muscle wires!

After you mentioned the cords' ability to engage with gears I started to imagine a variable tension robotic arm that had almost organic flexibility... and now apparently there are some Tensegrity Robot videos I need to look up! Also, at one point there it looked like you would have benefited from some sort of Really Useful Robot with a mechanical hand ;)

You need a robot arm to hold the structure up while you add the new strings. I wonder where you could get such a robot arm?

Sometime in the mid to late 70's my dad was given a 3D puzzle that I think I've only just now figured out thanks to you. It was a Tensegrity Dodecahedron with a glass sphere in the middle, suspended by the rigid members. The idea was to figure out how to remove the sphere but leave the structure rigid. When I say figured it out, I mean that while I was able to remove the sphere, my young, plastic mind could not figure out what was so unique about the structure. That's the part I've just figured out. Very cool! Thank you!

I spent quite a lot of time studying tensegrity during my BA. I decided to make a scale model of the famous tensegrity Georgia Dome. It was hell, I had like 100 less hands than needed. The thing only started being stable when the whole construction was tensioned. Almost missed the deadline on this one and the aesthetic result was far from perfect... Some other early examples of tensegrity in architecture were "Spodek" hall in Katowice, Poland (1964-71) and "Supersam" in Warsaw, Poland (1962).

The EXACT video I was looking for. I have been searching FOREVER for any kind of RU-vid video that talks about tensegrity without defaulting to the now ultra cliche, “impossible table”. It seems like there MUST be some application for this amazing property other than gimicky physics desk toys, so thank you.

A tensegrity robot covered in green screen cloth, would be an amazing semi-practical effect for a Blob sequel/reboot.

1:52 - You always want to make sure the rigid members don't touch.

I know I'm late by 2 years, but I just want to say that you are a _Saint_ sir! I've been mildly obsessing over tensegrity structures for the last few weeks, but there's suprisingly few resources actually going in-depth into structures (Most just touch on the floating table design). It's super cool that you made a 4-strut tensegrity, and even better that you made a tensegrity mast (The tensegrity stack). The best part, which I don't think I've seen a single person cover online, is you pointed out how springy the mast was, and then you showed and explained how you made it more rigid by adding more tendons! Absolutely incredible! Thank you!

There's a lot of academic interest in using dynamic tensegrity structures for deformable soft robots. Some of the demos are pretty neat and since the mechanical connection between actuation and the deformation of the structure can suffer some distance, you can stick your actuators wherever you want.

"So now I just need to find a practical use for it." Ad immediately plays. Well done.

I'm sure someone suggested already, but could you have printed the "rigid members" in clear or translucent plastic and fed LED strips through them? Then you'd have a lamp that was a sculpture without having to add things to the outside of it.

"furniture grade pvc" - learn something every day. (That, and that cords too) fascinating

When you said I see they sell really similar things on amazon I was not expecting those kinds of beads... hahaha

I've been thinking about doing a tensegrity project for a while, and that chain solution is a huge help! I couldn't figure out a reliable, easy way to fix the cables with consistent length. I might try smaller chains for more precise adjustment.

Great video as always👍 Thanks for sharing your experience with all of us👍😀

Loved it... This is as you say the most opposite of designs and builds you have created. Bravo, simply brilliant!

An interesting idea would be to instead of using many individual wires for each connection, use a few select wires that go across multiple connections, but you route it in such a way that if you pull on the starting point of the wires (say from a motor underneath) it would change the tension in a way that would cause the entire structure to extend or contract

You could use those structures when camping. Make some thing out of ropes and sticks, cover it with a blanket, and here you go.

I suggest orange lights. Alternatively, green tubes plus gold chains and many lights... and you’ve got a surrogate Xmas tree

Awesome break from the typical content. The music cracked me up, haha. Great Job!

Cool. Lights were nice addition. And, here's ANOTHER IDEA for an addition: MOTION-ACTIVATED "WOBBLER" MOTOR (perhaps a simple unbalanced mass on the shaft); might work best on one of the more "springy" configurations.

I first saw this when researching string puppetry for a robot head as the head was heavy and needed to pan and tilt but looked wobbly with the usual 2 servos underneath.

My Pal Ollie has just finished a PhD mostly looking at how we can use tensegrity principles to transmit torque from kites.

I read a biography on Buckminster Fuller and I still can't tell if he was a visionary or just a great salesman who knew how to repackage already existing ideas. None of his ideas gained him any commercial success, and not because they were ahead of their time but that they were just not great ideas. The tensegrity concept is an example of a valid claim of Bucky taking an idea and repackaging it with a new made up term, and he made up a lot of terms. His greatest known accomplishment, the geodesic dome, wasn't the first of it's kind. The first dome structures were built in Germany in the early 20th century for a Carl Zeiss planetarium. Josef Albers, a German architect who spent time at Black Mountain college while Buckminster Fuller was teaching there, may have been a conduit of this concept to Bucky.

Great job! This seems like the ideal building method for big structures in space.

I really like it. I'm thinking of building one in my garden and letting vines climb up it.

There are two types of Tensegrity: Internal tension and external tension. That is, where the tension is provided by forces on cables or other WITHIN the structure and where a force (usually gravity) OUTSIDE the structure provides the tension force. 01:28 is an example of an internal tension Tensegrity structure. 0:12 is an example of an external tension Tensegrity structure. While internal Tensegrity structure are a curiosity, external Tensegrity structures are very special. External Tensegrity structures are an example of Binal Dynamics: Binal (two) Dynamics is where a force is channeled in such a way as to (mostly) counter itself. In the external Tensegrity structure at 0:12 gravitational force pulling down on one side causes tension to increase in its opposing sides. The structure is then pulled back in to balance. The structure oscillates back and forth between its sides, while most of the the structure's weight is born by the tension-compression unit in the middle. Lift generated on an airfoil is another example of Binal Dynamics.

I hate the terminology of 'impossible' that clickbait has adopted, anyone who knows the basics of what's going on, and the meaning of the name, knows what this actually is. I'd be curious, if this is easily miniaturized, I know physics doesn't easily scale with size, if this could be a good vibration dampener. I wonder if this would be assisted by aligning the top-most endpoints with the bottom-most endpoints and linking them with a wire; so that you not only have triangulation between layers but also a solid link between the top and bottom polygonal faces. Though with this idea of a vibration dampener would only really work if the top and bottom face planes are parallel, maybe a central shaft that's telescopic would assist in keeping these planes parallel; as twisting deviating from a Y-axis (up axis, I'm used to Z-X being a ground plane with Y as a vertical) parallel would make something like a table unusable. As for tensegrity 'rollers,' I feel that they run into the issue that is best described as the rolling motion of a 'sphericon,' where the rolling motion isn't spherical, but rather a circular arc with a shift somewhere along the arc; basically the 'roller's can only sit flat where they have 3+ points of contact, meaning their 'rolling' motion is based on a transition between polyhedral faces, where those polyhedral faces are comprised of vertices from those 3+ points of contact. Where spherical rolling is optimal, tensegrity 'rollers' are limited to polyhedral structures, until we get to a vertex structure that makes this negligible; imagine rolling around an icosahedral die, or a hexahedral die, compared to a Zocchihedron, the trademarked 100-face die, that apparently has a patent protecting "spherical dice; containing ;multi sized and irregularly shaped particles." While the tensegrity-based polyhedra doe provide more flexibility to sphere-like rolling than rigid polyhedra do, I think we still need to look at polyhedra like the Zocchihedron before we can consider anything to have sphere-like movement. Though I do think tensegrity structures could lead to something interesting in robotics. Imagine putting a drum at the end of each cord that is manipulated by a motor, almost like a tendon-driven robot but with the added functionality of a tensegrity structure. I feel like this would result in a fully compliant tentacle structure, where you have direct manipulation of each 'joint' but have direct and indirect compliance within the structure to allow for natural movement, resulting in multiple degrees of freedom within the compliant range, if not directly a full 6 dof range of compliance.

I've only got one rigid member but it still appears to defy gravity.

Looks so cool. Another creative project by James.

serveros + tengserity + arduino = sick robot

Brookhaven College just north of Dallas, installed a tensegrity tower in the middle of the campus with a vertical pipe at the top that was supposed to support an electricity generating turbine. The massive steel pipes made a very distinctive tower, and Brookhaven used it as a symbol of the campus, but unfortunately the turbine head never worked well and was finally removed. After several years the town of Farmers Branch objected to the height of the tower that wasn't serving its intended purpose. When it was disassembled, the risk of the steel pipes escaping control meant that the entire campus was closed down for several days. The star pattern of the top view of the tower is still used in the college logo, which can be found on Wikipedia

Beautiful ideas

Steve Mould just made a fun video about this too

The most widely used tensegrity structures are microphone fixtures nowadays (for vibration insulation).

That's so cool. Even though I know how it works now, it still blows my mind.

Do an arch with that design

Nylon rope is one of the "springiest" ropes. Meaning, while it's quite strong, it has a lower spring constant than other types of fibers. Consider upgrading to polyester. Or even better to "vectan" or "Spectra".

the strings are perfect for this project, great idea. instead of the very 'fat' black caps you could make slots in the ends of the blue tubes?

That's um.... Uh.... Hey! I've got an idea! Build a computer chair that doesn't fall apart every few months. All their connections tend to go bad, and before long, you're sitting on a hill. A tensegrity chair, set on the 5-spoke wheelbase thing of a busted chair (with the low-friction speedwheels upgrade, of course) would be a much more worthy project than that lamp, IMO.

The one at the Smithsonian has progressively shorter segments which look really good. Pick a pleasing ratio, like 33%, and it should be more esthetic.

First unique tensigrity design

Correct me if I'm wrong...but isn't a bike wheel basically a 'tensegrity structure'? I mean the wires certainly aren't in compression...

Nice ! Could you 3dprint a piece to press inthe top middle of the structure to demonstrate its compression ?

I think you could turn that into a musical sculpture by using different thickness and shape pipes with the right material as the rigid parts and long extension springs instead of wire for the tensioning. Just leave the pipe ends open. The extension springs create alot of vibrations that are transferred to the pipes to make sound.

The chain from Amazon is vertical venetian blind chain. You can tell by the little clips it has at regular intervals, to clip on to the blind slats.

This type of structure is also super good at absorbing falling shocks!

After seeing you fiddle around with the tubes and wires, I guess constructing the Needle Tower must have been an absolute nightmare. 🤯

Slightly transparent tubes with lights in and the wire used for tensioning might be good :)

Great video!! Thanks!

OMG ! Thanks so much for this video. Faith in humanity restored. I can’t believe how much people paid attention to the gloating tables (pun intended) in contrast to the idea which is so much more greater.

Could you make a retractable springy robot arm that collapsed/expanded by loosening and tensioning vertical strings?

"why there's more to tensegrity then tables" almost makes a table

That was really clever, but aesthetically these things seem to look better when they've got fewer struts. I thought the skylon at the festival of Britain looked amazing (only ever seen photos) and I guess that must be about the simplest tensegrity possible.

You made a tensegrity christmas tree!

Really Cool!!!

To solve the problem of assembling the second layer, could you suspend the first layer, then assemble the second layer hanging below the first layer?

What would the weight limit be if one were to make a table out of a structure like the one made here?

Tensegrity springs. Purposefully using the inherent wobble of a simple tensegrity structure as a spring in whatever you choose to do. Could do different versions, a compression, torsion, and/or tension springs for some amazing things!

Next Christmas you should make a tensegrity Christmas tree.

A bit late to this vid, but you could use the upwards facing ends as hat hangars by attaching extension rods to the endcaps (You may want to consider heavier duty cords for coat rack duty). It'd be a nice conversation piece for house guests.

I wonder if this could be used to build taller buildings that are lighter. Concrete compression beams and steel cables for tension like a suspension bridge.

"This is a complex structure with three rigid members" Hang on I thought I was on RU-vid...

Would be a nice showpiece.

Maybe use magnets and coils and have it wiggle in the wind and generate electricity

Bimbling about with the ropes building up the tower really makes you appreciate that big ass needle tower. The actual art in there might just be the ability to build it at that size and weight

hang it up side down and work down

Video: Theres more than impossible tables. Me: Impossible chair?

love the structure ! one question , they are all spinning CCW , what happens if you alternate CCW and CW ? or other pattern ? does it impact the bouncyness ? does it look good ? ok it is more than one question :X :D

This is just waiting to be turned into a Christmas tree

Pretty cool

do you think your structure would make for a good vibrational dampener?

Amazing

Just made a tensegrity table 👊🏽

Nylon is actually pretty stretchy. Try a polyester line or maybe even dyneema. You probably done need so many extra connections with dyneema

Can you use magnetic force as a form of tension?

Listen guys, you gotta have an equalibrium going on. If there is no equalibrium, your rigid members will touch and we do not want that to happen.

It would make an interesting christmass tree

Color-coded rubber bands would have been very helpful when illustrating how to construct the thing.

every time he says rigid members i die

What if you had transparent tubes with lights in them and the tubes received power through the cables.

Do you have instructions on how to make dis step by step?

You can save a lot of filament with tree supports

I would like to see your take on a tensegrity rover!

Anyone else find it ironic that such a masterful robotic engineer with a 3d printer and hundreds of motors lying around is doing his photo shoots rotating a platform by hand?

Name: **Impression of a blue police box that displaces through space over time**

A Tensegrity Christmas Tree 🎄

The Needle Tower and horizontal Dragon sculptural forms are the foremost extensions of Snelson's artistic engineering concepts, but I find sparse information about the actual methods of tensioning, and measured forces involved - some of which seem very high, given the angles of intersection, and height or length of extension in 60 or more feet, where many thousands of pounds of force would be demanded of each cable. Though the forms are far lighter than rigid structures, the basics of construction cranes, with open spans of rigid beams with triangular reinforcements, and sometimes additional cable spans to bear loads at longer horizontal spans, has proven utilitarian, where rigidity makes members strong in both tension and compression, and torsion as well. The gimmick, of tensegrity structures, overall, is an inherent visual paradox viewers cannot fully accommodate, rather than satisfying a deeper aesthetic appeal. The fascination with the open forms, repeated, still seems lacking in some quality needed to elevate the concept to a more fully artistic realization, despite Snelson's commitment. Perhaps the coldly abstract tubes and cables are unrelatable as artistic materials; his experiments with bamboo are akin to the construction scaffolds used in Asia, where the materials are organic, and a bit contradictory to their engineering applications, which actually makes them more appealing somehow.

the bot like to see is 1 of your endcaps self attach and pull it self up and down the cable so that no cutting and self tighening

... why didn't you simply count the beads?

that structure is soo tense

I would have turned it into a coat rack adding a heavy base plate to avoid it tipping over when a jacket was hung

Thankyou

I wonder if it would be practical to make a building using this technique

If that would be more conical form then can mimic the Christmas Tree :)

Im sure this video will be shown at technical universities

9:26 "So now i just need to find a practical use for it" implying that being awesome isnt a practical use.

ART (A Radiant Tensegrity)