Why there's more to Tensegrity than 'Impossible Tables'
Вставка
- Опубліковано 31 січ 2021
- I wanted to explore Tensegrity as an engineering concept. Quite a few other UA-cam channels have made 'impossible tables' which in reality use Tensegrity - the combination of rigid members, and tensioned cords' to support themselves. However there are many other structures that can be made using Tensegrity.
Get the CAD from: github.com/XRobots/Tensegrity
You can support me on Patreon or buy my Merchandise:
***************************
Patreon: / xrobots
Merchandise: teespring.com/stores/james-br...
***************************
Affiliate links - I will get some money of you use them to sign up or buy something:
***************************
Matterhackers 3D printing supplies: www.matterhackers.com?aff=7500
Music for your UA-cam videos: share.epidemicsound.com/xrobots
***************************
Other socials:
***************************
Instagram: / xrobotsuk
Facebook: / xrobotsuk
Twitter: / xrobotsuk
***************************
CAD and Code for my projects: github.com/XRobots
Huge thanks to my Patrons, without whom my standard of living would drastically decline. Like, inside out-Farm Foods bag decline. Plus a very special shoutout to Lulzbot, Inc who keep me in LulzBot 3D printers and support me via Patreon.
HARDWARE/SOFTWARE
Below you can also find a lot of the typical tools, equipment and supplies used in my projects:
Filament from: www.3dfuel.com/
Lulzbot 3D Printers: bit.ly/2Sj6nil
Lincoln Electric Welder: bit.ly/2Rqhqos
CNC Router: bit.ly/2QdsNjt
Ryobi Tools: bit.ly/2RhArcD
Axminster Micro Lathe: bit.ly/2Sj6eeN
3D Printer Filament: bit.ly/2PdcdUu
Soldering Iron: bit.ly/2DrNWDR
Vectric CNC Software: bit.ly/2zxpZqv
Why not join my community, who are mostly made up of actual geniuses. There’s a Facebook group and everything: / 287089964833488
XROBOTS
Former toy designer, current UA-cam maker and general robotics, electrical and mechanical engineer, I’m a fan of doing it yourself and innovation by trial and error. My channel is where I share some of my useful and not-so-useful inventions, designs and maker advice. Iron Man is my go-to cosplay, and 3D printing can solve most issues - broken bolts, missing parts, world hunger, you name it.
XRobots is the community around my content where you can get in touch, share tips and advice, and more build FAQs, schematics and designs are also available. - Наука та технологія
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 UA-cam Channel Members have next week's video already!
Build a Tensegrity robot! ;:D
I was hoping that you'd made a tensegrity robot. :-(
Hi James! Love your channel. My research is actually IN the application of tensegrity structures. There are a TON of benefits to replacing rigid bodies with tensegrity structures including weight reduction, energy absorption, and locomotion. Let me know if you have more questions on tensegrity!
Try building a tensegrity quatruped with flexible spin pls
Your end caps look great! They sure make ball chain easier to work with.
Muscle wires!
Cool idea!
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 ;)
I'd really like to do a robot based around this, but wait for the next video...!
Holy moly that would be insane
@@jamesbruton Getting a fully articulated hand will be very interesting.
@@evannibbe9375 for a stiff member
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?
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).
As a bonus - a photo of my tensegrity christmas tree :)
www.deviantart.com/beezqp2/art/Tensegrity-christmas-tree-500622733
@@bzqp2 Nice. Was it symmetrical? It's hard to tell. Tensegrity structures always look like a bit of a jumbled mess in still photos and only when you see them rotating (or see them in person, I suppose) does all the symmetry become apparent.
@@nagualdesign yea, each segment was centrally symmetric
A tensegrity robot covered in green screen cloth, would be an amazing semi-practical effect for a Blob sequel/reboot.
Or even a pneumatic bladder thing, there's a robot for it already, but it very small.
1:52 - You always want to make sure the rigid members don't touch.
that would be gay
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 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!
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 think you just invented the tent!
⠀
⠀⠀⠀T⠀⠀E⠀⠀N⠀⠀T⠀⠀S⠀⠀E⠀⠀G⠀⠀R⠀⠀I⠀⠀T⠀⠀Y⠀
⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ camping redefined
⠀
The EXACT video I was looking for. I have been searching FOREVER for any kind of UA-cam 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.
My problem with these is that it sort of makes sense that the rubber bands keep things pulled together tight. With the 'gimicky physics desk toys', you can build them so that string or fishing line holds them together, making it harder to understand why the structure does not collapse, especially when supported with only a few lines. Taught science forever and I love the 'how and why' of science. These kinds of structures have many applications, however and I am starting to work on some of the simpler ones.
"furniture grade pvc" - learn something every day. (That, and that cords too) fascinating
"So now I just need to find a practical use for it." Ad immediately plays. Well done.
This is great, you are obviously one of the smartest guys on UA-cam. It's nice to have a video less complex and something we could follow along with at home.
Loved it... This is as you say the most opposite of designs and builds you have created. Bravo, simply brilliant!
1:35 Exactly how many rigid members does one man need?!
Great video as always👍
Thanks for sharing your experience with all of us👍😀
Thanks, I'm pretty sure there's more to this type of structure with some moving parts.
Awesome break from the typical content. The music cracked me up, haha. Great Job!
Awesome! Really enjoy all the explanations you give
Looks so cool. Another creative project by James.
Great job! This seems like the ideal building method for big structures in space.
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.
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.
I really want to combine it with next weeks concept piece which is an alternative robot idea.
The nasa one is nice. It's springy and it was meant to land on Mars without airbags. I kinda want to fool around and build one too, but the kinematics to get motion and the actuation looks really difficult to do.
Great video!! Thanks!
Beautiful ideas
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.
That's so cool. Even though I know how it works now, it still blows my mind.
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.
When you said I see they sell really similar things on amazon I was not expecting those kinds of beads... hahaha
I really like it. I'm thinking of building one in my garden and letting vines climb up it.
Really Cool!!!
My Pal Ollie has just finished a PhD mostly looking at how we can use tensegrity principles to transmit torque from kites.
serveros + tengserity + arduino = sick robot
Steve Mould just made a fun video about this too
This type of structure is also super good at absorbing falling shocks!
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
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.
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.
I suggest orange lights. Alternatively, green tubes plus gold chains and many lights... and you’ve got a surrogate Xmas tree
Yep, this technique is quite nice for a christmas tree!
www.deviantart.com/beezqp2/art/Tensegrity-christmas-tree-500622733
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.
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.
Pretty cool
Amazing
"why there's more to tensegrity then tables" almost makes a table
The most widely used tensegrity structures are microphone fixtures nowadays (for vibration insulation).
Slightly transparent tubes with lights in and the wire used for tensioning might be good :)
I would like to see your take on a tensegrity rover!
After seeing you fiddle around with the tubes and wires, I guess constructing the Needle Tower must have been an absolute nightmare. 🤯
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.
I've only got one rigid member but it still appears to defy gravity.
Technically a cantilever.
@@Confuseddave That's what she said.
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
First unique tensigrity design
You made a tensegrity christmas tree!
Thank you for amazing content and inspiring me to do engineering
Do an arch with that design
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?
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.
The truth is that his ideas are more democratic, and therefore less appealing to the shapers of society who will always be conservative due to the nature of their self-interest. Bucky envisioned a world of industrial Harmony with 10 billion well-fed citizens each with a home and mode of transport, sufficient for their comfort, prosperity, and recreation. His designs were not necessarily the most efficient ever conceived but they were at a level to demonstrate the validity of his proposed concepts, each to be further developed as it engaged more and more realistically with the practical world. To achieve a similar economy of scale and efficiency of industrial vision, a strong government would need to subsidize it's systems and implementation. Impossible in a political system powered solely by social friction. He may not have invented all the wild concepts that he promoted, but he recognized their sophistication, utility, and curated them into a coherent vision for a future society that would not destroy the Earth even out past a burgeoning population of over 10 billion citizens. If one produces an industrial economy of scale for the sustenance of the human population, it intrinsically reduces the quantity of profit taken in by those that would fleece us with unlimited goods and services, each billed separately, while we transport ourselves and live in constructs of planned obsolescence which fuel the debt economy.
So yeah maybe his inventions were a little bit boring, but like for instance the telegraph itself is fairly boring, the reason for the utility of a rubber tire itself is fairly boring, the pure engineering concept of rigidity is kind of boring but the sheer quantity of work that these things get done for humankind is incredible and those are the types of concepts that Buckminster focused on.
This has A Lot of uses for acoustic coupling. Since they act like springs but are also very controllable so the use of tensigrity structures for loudspeaker isolation as the mechanical oscillation travels poorly through the structure (same as springs) however unlike springs, they look cool. However as far as I know there isn't any comertial offerings only research based papers
Nice ! Could you 3dprint a piece to press inthe top middle of the structure to demonstrate its compression ?
Would be a nice showpiece.
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!
Video: Theres more than impossible tables.
Me: Impossible chair?
"This is a complex structure with three rigid members"
Hang on I thought I was on UA-cam...
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.
Speaking of conversation pieces, if I had my way, I would have a tensegrity piece on EVERY flat surface in my house where visitors might see them. Wish I had know about them when I taught science. Great for teaching concepts, how and why thinking, etc.
Congrats, you made a Christmas tree!! ))
This is just waiting to be turned into a Christmas tree
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".
Just made a tensegrity table 👊🏽
Thankyou
Next Christmas you should make a tensegrity Christmas tree.
Yep, should have been a Christmas project really.
hang it up side down and work down
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.
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.
It would make an interesting christmass tree
Nice
every time he says rigid members i die
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
If that would be more conical form then can mimic the Christmas Tree :)
Name: **Impression of a blue police box that displaces through space over time**
You can save a lot of filament with tree supports
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.
Could you make a retractable springy robot arm that collapsed/expanded by loosening and tensioning vertical strings?
nice
A Tensegrity Christmas Tree 🎄
that structure is soo tense
LOL :-}
Maybe use magnets and coils and have it wiggle in the wind and generate electricity
excellent idea, and engineer it so it gives out a different frequency or waveform at different windspeeds and direction; a windspeed/direction meter that generates its own power for its output!
@@ozzymandius666 Just stick with the current models of wind generators. They are more efficient, unless you just want to attract attention to your generator. "Hey everybody, look at my tensegrity generator!" LOL
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
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?
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.
Yes, this is easily miniaturized. Apparently, at micro scales, we can see tensegrity structures in biology. Due to each rod/string being in perfect compression/tension (respectively), tensegrity structures apparently can have remarkably high stiffness to weight ratios (which actually means that it is actually pretty useful in space, where each gram comes at a premium).
Nylon is actually pretty stretchy. Try a polyester line or maybe even dyneema. You probably done need so many extra connections with dyneema
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 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
What would the weight limit be if one were to make a table out of a structure like the one made here?
do you think your structure would make for a good vibrational dampener?
Can you use magnetic force as a form of tension?
I would have turned it into a coat rack adding a heavy base plate to avoid it tipping over when a jacket was hung
Do you have instructions on how to make dis step by step?
Color-coded rubber bands would have been very helpful when illustrating how to construct the thing.
Nice music
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.