We should use this amazing mechanism that's inside a grasshopper leg
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Mechanical power amplification is found throughout nature and humas use it in tools and devices.
Dr Bill Heitler's website about the grasshopper: www.st-andrews.ac.uk/~wjh/jum...
Ant Lab's video about the trap jab ant: • Does the snap of a tra...
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00:00 Intro
02:30 Obtaining Skyrim's most broken weapon
08:00 The rest of the video - วิทยาศาสตร์และเทคโนโลยี
Also, the hinge from an overhead cabinet! That's like the last mechanism too.
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What about a ZIF (Zero-insertion force) socket?
a foldable phone also snaps open at a certain point and gets locked
@stevemould Mole grips, or some folks call them locking pliers, use the locking mechanism - an "over-center" cam action.
A kiss is a bit like that, you build up potential energy in your mouth (vacuum) and when you open it the air rushing in makes a "kiss" sound.
Venus Flytrap!
This video is all about storing energy slowly and using it quickly, but there might be interesting instances of the opposite as well. For example, when winding a mechanical clock, you are storing energy quickly and then using it slowly. The purpose there is to allow the energy to be released over the coming week so that you don't need to apply energy continuously to keep it going.
Mechanical watches fascinate me. The escapement mechanism is so clever.
Nice!
The really interesting question here is are there any examples of such a mechanism in the animal kingdom?
@@somitomi interesting question! There are obviously chemical versions like hibernation and such, but I wonder if there are any mechanical ones.
@@somitomi maybe gliding in birds and things like flying fish/squirrels/frogs. Build up gravitational potential to release over a long descent.
Mantis shrimp: offended
Exactly what I was thinking
@@GrayCowMan Same, I was writing the comment before thinking, "wait, pretty sure someone got it covered".
This.
There's some species of planthopper insect that uses a biological gear as a youth to support jumping, before maturing to a form whose exoskeleton lacks the adumbrations
Pistol Shrimp as well.
The mechanism you're describing is an "over-center" one with a spring (or any elastic deformity in one or more of the parts that effectively acts as a spring). The tension or compression can be applied an many ways. An elastically compressible cam shape, or an elastic bit that a solid cam shape rides against, can be made to work.
Vice grip pliers, all manner of electrical switches with a snap action, toggle style latches, ring binders, old-school skeet launchers, some folding sofa-beds, etc. use this type of mechanism.
RING BINDERS! That's what I was thinking of, and I bet it's what Steve was thinking too.
Don't forget butterfly patches on a road case. You see them a lot on mobile sound equipment.
Smarter folk than I: is this the same mechanism the dung beetle takes advantage of while rolling dung?
Each roll starts hard as the beetle pushes with it’s coiled legs against gravity however as it extends it becomes easier once the tipping point is reached.
@@garb7477 In seeking to answer your question, I tried watching a couple of dung beetle videos. No, I do not think they're using a sprung over-center mechanism. I think they're just going from a low lever advantage to a high lever advantage as the pivot points of their legs come closer into alignment.
It's the same thing as standing from a squat position. It's the most difficult at the lowest point, and gets easier as your legs straighten up.
something similar that came to my mind: as kids we used to put rubber bands around pencil boxes with a hinged lid and a latch to hold it close.. the latch gets damaged over time and we used to put rubber band around the box to prevent it from opening while inside the bag.. but when it's time to open the pencil box, we rarely pull the rubber band off and instead stretch the lid open along with the rubber band, and once the lid has opened more than 180 degrees, the rubber band would keep the lid open.. then all you need to do is give it a slight push under the lid and it will slam shut
15:06 "...your arm is QUIVERING holding the bow at full draw."
Good one.
has a modern compound bow that appears to be doing most of the work for him lol
Says calling it a catapult would be confusing and shows a trebuchet. 🤔
I was going to make this same comment.
A trebuchet is a type of catapult.
@@SteveMouldthank you was going to make this comment
@@SteveMould A catapult wishes it could launch a mass of 90kg over 300m!
@@SteveMould for the definition of catapult to be wide enough to include trebuchet, it then also includes slingshots and bows.
The linkage you are thinking of is called an over-center mechanism and they are used everywhere! Some common examples would be vice grip pliers, toggle latches, and clamps.
I think the closest equivalent to what he built would be a clay pigeon throwing machine.
Yes, this. Also, snap switches like common light switches
and of course, firearms. for instance, the Luger's funky look is mainly cuz it uses a toggle to delay the chamber from opening
I believe horses and other prey animals use them to rest standing, so they are always ready to run for their lives
Thank you!
Ballistic Seed Dispersal (ballochory) - cress pods, touch-me-nots and others, tension is stored in a 'just barely stable" state in the pod wall, the smallest disturbance tips the balance and a huge elastic release of force expels the seeds.
Nice. @Steve Mould here is the answer to your question about where this is found in nature.
I saw that bistable switch model before in a Veratasism video called "Why machines that bend are better."
All good electrical switches have a mechanism that stores energy one way or another to make sure the contacts close firmly or open completely. There is always an energy hump as the mechanism goes from one stable state to another, which is why there is a snap action. As the contact points come together, the motion continues just a bit before it stops. This causes a wiping action that cleans the contacts so they work reliably. The handle that you touch and the inner electrical part are connected with a spring, so two bistable parts work together. That way, the handle can be at that state in between the stable points and the electrical part is fully stable.
The last mechanism reminds me of staplers -- when you open them up to refill them, there is a similar mechanism with a hinge and a spring.
Oh yeah!
That's 💯 what I was trying to think of
Spring assisted knives are another example of this, in the other direction: While closed, the spring holds them closed, but if you open them slightly the spring pulls them all the way open.
This was my thought too! But there is also something else it reminds me of, I remember the feeling of playing with something similar as a kid, trying to balance it on the unstable point.
I wonder if there is something like a venus flytrap which makes use of a similar mechanism.
@@QuargCooper I remember having a toy that was a series of wooden blocks connected by elastics that was something like this. there were notches in the blocks for the elastic so you could position the blocks either end to end or at a right angle to each other in a stable state, or if you put the corner of a block into the notch of the next one, you could try to balance it at a 45 degree angle (or 135 if you prefer). Steve's model also had me wondering about what kind of mechanism venus flytraps use!
Okay so never in my entire life have I been able to snap my fingers due to inadequate explanations of what I'm supposed to even be doing and then at the age of 42 a single Steve Mould explanation has me doing it first time. What a world we live in.
Never been able to snap, still can’t. My issue is I just can’t get the right angle and my fingers either slip, or the nails bend and cause extreme pain, then my flesh slips quietly, or the nail breaks, or both…
My soloution? I don’t snap (:
@@chtechindustries4174 Perhaps you understand this, and if so please disregard, but I think a common misconception is around *where* the sound is produced, which leads to confusion around how to produce it. The "snap" we hear is the sound of the finger, having slipped off the other finger, slapping into the fleshy bit at the base of your thumb. The interaction of the fingers with each other is only relevant to the extent that it stores energy to allow one of them to subsequently slap into the bottom of the palm with greater force. To directly address what you said, you WANT your fingers to slip after a moment of friction, and quietly is really the only way they'll ever do so. Moreover, nails shouldn't factor in at all since you're aiming to squeeze flesh against flesh (typically, the fingerprint of your middle finger against the fingerprint of your thumb--this allows more friction than anything involving nails). Because, again, the sound you're trying to produce happens AFTER your fingers have slipped off each other, when the middle finger slams downward and impacts the flesh at the base of your thumb.
So, basically: Lightly curl your pinky and ring finger against your palm. Now, squeeze the flesh of your middle finger against the flesh of your thumb as hard as you can, so that your thumb and middle finger are effectively parallel. Your index finger can either help squeeze the top of the middle finger, or else stay out of the way entirely. Now, while holding this squeeze, gently move your thumb off to the side, as if you were going to make a thumbs-up gesture. In other words, destabilize the squeezy equilibrium you've established. This will "release" the middle finger to slide off and quickly snap downwards (all four fingers should now be resting across the base of your palm with your thumb in a vaguely thumbs-up position). When your middle finger impacts the fleshy base of your thumb, it should produce some kind of sound. The faster you can make it slap downwards, for example by increasing the friction between your finger tips and, commensurately, the squeeze force this allows, the louder and more percussive that sound will be. Any adjustments you may have to make should be with a view to increasing this impact, NOT increasing any sound from your fingertips interacting prior to the actual snap.
YES I JUST FOUND OUT HOW TO DO IT!
i've been rubbing my thumb and index finger togetehr thinking thats what made the sound
bit obvious what you're supposed to do. it's not as wild of a world as you say upon realising you're just not too bright
"inadequate explanations" i think nobody even cared of explaining it since its an intuitive thing to do by observing someone else doing it. I'm only finding out through this coment that there are people that don't know how to do it.
Click or Snapping beetles are a good example of the elator mechanism
You've explained all these concepts in physics better in a 20 minute video than my profs did in a 12 week university course.
Hi Steve. An example of the mechanism you showed can be found in the human body. The "tensor fascia lata" originates from the pelvic bone "the iliac crest" and inserts onto the outer side of the knee. It is a long thick fascial structure that is tightened by a small muscle originating from the pelvis called "the tensor fascia lata". This muscle's function is intriguing, as it spans and controls two major joints -the hip and the knee-, and operates as a joint extensor when these joints are in extension, and a flexor when these joints are at 20 degrees or more of flexion. It effectively operates as a locking mechanism for the hip and knee to allow us to stand without having the spend too much energy through the major muscles -glutes and quads-. Its resistance to motion follows the same pattern of change that you highlighted in your hinged joint with an elastic band, and is least effective at 20 degrees of flexion.
What he said :)
Woah, thats so cool
That's really interesting, thank you!
I didn't get how it helping us to stay without spending too much energy, where I can see this on video or something?
@@user-mc5oh2pl7t Have you ever locked your knees when standing in place? This is what OP is referring to.
I noticed as a kid the best way to catch a grasshopper was to get it right after it landed, as it seemed to take a second or two to get itself ready to jump again. It would then jump half cocked, only going a short distance, making the follow up quite easy.
My family has ducks. They love eating grasshoppers. They almost always forage as a team. One reason is likely that a bug hopping out of the path of one duck will be easy pickings for the next one over.
Also true of the Spotted lanternfly - they jump quickly enough to escape your first attempt, are easier to get on your second attempt, and they're sitting ducks for your third swat (or stomp).
@@JWQweqOPDH (guessing your not in NZ...) we have a sparrow sized bird called a fantail.. basically has a wide fan for a tail it flits around, scaring insects into moving/flying, only to turn 180de in its own body length and catching them...
While throwing plastic at trees (I play Disc Golf) they often flit around your ankles or shoulders if your by a bush, getting the insects you disturb as a freebee... (They aren't very scared of humans.. I've had several momentarily land on a foot/arm then gone again in a flash.
what i like about this channel is how succinctly the information is delivered without any of the pretentiousness that this type of channel always have.
he presents the information extremely smoothly and coherently without trying to make himself the star of the show and that's a quality i sincerely can only wish to strive for...
this is not as hard to understand as it is to explain it in such a clear way!!! Wonderful job!
THE KNEE! The mechanism can be found in our knees. The force of the rubber band is the gravitational force on our upper body. This way we don't need much energy standing upright. Also, this is the reason why the toggle mechanism is called 'knee lever' in German :)
Yep. What is the german for 'tension clasp?' The actual device, not literal translation, because that is likewise one.
@@mandowarrior123 You mean Kniehebelspanner (Knee-lever-tensioner)? But yes, that's exactly what I thought of!
this is the one i thought of
and some people's knees can bend further allowing them to stay upright with less effort (but it looks painful and a little unnatural)
I was thinking about folding smartphones
"[...] For example, the soft living actuator of a Venus flytrap leaf (Figure 1A) has two stable equilibrium states, namely, an open convex shape (one stable state) and a closing concave shape (the other stable state). It can switch rapidly between these two stable shapes to achieve fast closure in about 100 ms.[53, 54] It utilizes the so-called bistable snap-through in engineering.[55] Similar bistability is observed in hummingbirds for rapid beak closure in a few milliseconds to eat flying insects (Figure 1B),[56] in the earwig wings to fold and lock their wings[57] (Figure 1C) [...]"
- Chi, Y., Li, Y., Zhao, Y., Hong, Y., Tang, Y., & Yin, J. (2022). Bistable and Multistable Actuators for Soft Robots: Structures, Materials, and Functionalities. Advanced Materials, 34(19), 2110384.
^^^^^^This is the one!
I am pretty sure crocodiles do the same with their mouth.
great citations too. hope he sees it; seems to be exactly what he was looking for
I knew it when I saw it. I think clams might be similar too
I was thinking Venus Flytrap too, although it seems it goes from one equilibrium state to another (convex to concave), so doesn't seem like it stays in that sweet spot between the two. The jumping popper toy seems like an equivalent human invention.
Awesome! I have been thinking about these bows for a long time and wondered if and how these potential movements are possible with levers. Thanks for the visualizations!
Thank u Dr. Bill Heitler for the clear photos.
Also, thank him for the E in his name
The hinge mechanism shown around the 12 minute mark is quite similar to a motorcycle kickstand. It uses a fairly strong spring to keep it in the upright position, as you wouldn't want it coming down while riding. But pushing the kickstand down will eventually find a new stable position where it will stay down all on its own, but give it a little tap backwards and it will release and swing all the way to its upright position. And of course when fully down its actually canted forwards so the weight of the bike also holds it in place securely.
Also, I'm glad you mentioned clicking or snapping your fingers. That was on my mind for some time there, lol
that's what was in my mind during that part. cept bicycle kickstand of course. it was a metal arm and spring that went past the hinge... I just couldn't visualize what it was attached to lol
I agree, I was thinking about one of those over center mechanisms as well like a kickstand or a latch.
Passenger trains where i work on have over center door locks. Used as a safety feature.
Tiddlywinks.
If I'm not completely mistaking, this is the way wild oat seeds 'walk'.
The power of each 'jump' is build up by the seed drying during the daytime, whereas the release is triggered by humidity at dawn.
Nice! I was thinking of those little rubber dome toys that can be inverted and then ping up. The same sort of mechanism is used in venus flytrap leaves, as somebody already mentioned
never heard of these plants seeds. thx, i'll read some more about them
I came here to comment on the seed pods, but will settle up voting your comment.
They don't really use a small and kinda quick force to start that motion, so that's not an example of his idea, but yea thats a cool example in general
Found a very cool video demonstrating this ability of wild seeds from Planet Earth.
Not so sure it'd count for that particular mechanism though; while the sun applies energy and stores it in the fibres, it doesn't take any energy to release it as the water soaking in doesn't contribute any energy as far as I can tell. It's not held past a pivot point and doesn't snap out of its position, but rather unwinds.
I suppose it depends on what you call fast release and whether the whetting of the fibres count as unlatching it. It's at least adjacent to the mechanism mentioned and deserves an honorable mention though.
Either way it was an interesting video to watch so thanks for the suggestion!
When you asked for examples i was going to mention a compound bow. Glad i waited till the end of the video!
I see the work of a masterful brilliant mind when I look at these creatures. Truly amazing. Thank you for the great explanation of the mechanisms.
This kind of release of energy comes up on a small scale in linguistics; there's a whole set of sounds called plosives (say "puh, tuh, cuh, buh, duh, guh") where the sound is made by forming a seal with your lips/tongue, building up air pressure behind it, and then releasing it. Blowing a raspberry or buzzing your lips works the same, only you're holding your lips in such a way that when the seal is broken, it closes again a split second later and the pressure resumes building up, resulting in that oscillating "thppppt" sound.
The vocal folds (aka vocal cords) themselves are another example in the same realm. They open and close rapidly as air is pushed past them. The difference in these examples compared to what Steve is talking about is that the purpose is not force amplification, but sound production.
@@bomafett This is NOT amplification, just force storage and measured release. Steve is simply wrong.
@@protoborg Steve isn't wrong, you just seem to have completely misunderstood what force is. "Force storage" doesn't make any sense, you can't store a force. What you can store is energy, and energy storage can be used for force amplification just like the video explains.
And very similar to this would be coughing.
Yes! Great example, thank you
That footage of the ant flinging itself several times it's body length from its attempt to bite the skin is amazing.
Here in Western Australia we have the "trigger plant".
Evolved to trap insects for pollination or some species for consumption.
The stamen and style of the flower are fused into a column, which can look like a club.
The column is slowly pulled back under the flower and "locks in place, when a insect lands on the flower and touches the trigger hairs the column is released and strikes the insect where it is stunned and releases previously collected pollen for fertilization or trapped to be slowly dissolved for food.
The strike is one of the fastest movements in the plant kingdom, taking as little as 15 milliseconds.
Some plants launch their seeds with a mechanism in which a plant tissue dries out slowly, building up potential energy until the latch mechanism that holds the seed pod closed is overcome, then the pod opens and seeds are launched outward. Examples are Oxalis stricta and Oxalis corniculata (both are types of clover), witch hazel, and jewelweed. There might be an over-center mechanism involved. Not a botanist, so I don't know.
Really common man-made over-center mechanisms include the latches on tackle boxes and tool boxes. Luggage also has over-center mechanisms that allow you to over-stuff your suitcase and still keep it closed on long, bumpy trips.
Enjoyed this video. Make a part 2!
2:56 The irony of saying that calling a slingshot a catapult is a little confusing when showing a trebuchet and calling it a catapult is too rich. Love your videos.
I thought the same thing xD
@@Globss Same I was just about to comment this xD
A trebuchet is a catapult. What most people call a "catapult" is technically called a 'mangonel' or 'onager'.
Slingshot? Let me show you its features!
Right. So we're using a planet's gravitational mass to change our trajectory then...
12:35 Light switches function almost identically to this mechanism to initiate contact quickly. It's why they have the "snap" sound effect (thank you Technology Connections) and why you can balance a light switch between On and Off positions.
The funny thing about this, is that while Steve was trying to think of good examples he probably used a light switch multiple times lol. Sometimes a good example is so mundane you just don't see it!
Lol I was thinking the same thing. Light switches, and all kinds of rocker switches use this. Because if you turn it slowly with a load the contacts will arc, the over center mechanism snaps quickly between open & closed to prevent the majority of the arc. Circuit breakers actually work alot like his compliant mechanism with the stop on it, where it's easier internally for it to trip and turn off than on
@@danemoeckel2518yeah, circuit breaker was another thing that came to mind when he described the mechanism at play. Definitely fulfills the "minor force -> major force" requirement.
Over center mechanism. Great example.
Vice grips use over center mechanism to both provide (function of tangent) force multiplier a past center latch.
i was going to say flicking and i didn't even think about snapping until you mentioned it, i love your channel and all the work you do for your videos. they truly are entertaining:) thank you
Amazing amazing amazing explanation and visuals. Thank you!👏👏👏👏
"I want to get this ball moving fast enough to-" I gotcha, gunpowder!
As soon as we evolve gun hands, we're golden.
h/t _Harry Potter_
“There is an object in the distance that I would like to puncture a hole in”
He’s got a bit of American in him
My exact thought the moment he explained his issue, I was already listening to the eagles outside and the national anthem
Just call it a chemical spring and you are good to go.
Please. He's talking about naturally occurring mechanisms. Try and keep it realistic?
...
**Bombardier Beetle has entered the chat**
Fun bit of new information
the plant hopper was recently found to have GEARS in its hips so that when it jumps both legs are forced to move with the same speed and power, keeping its jump straight
Awesome video again, I love how you show the usage of those mechanisms, where you never think about :D.
14mins in.. this arrangement used a metal catch on wooden box lid to keep it shut. Or sometimes used as principle mechanism of a "Toggle clamp" to hold down wood working pieces.
If you can make a functional example of the saddle shaped spring and mechanism of a mantis shrimp club I'll be the first to click. That would be so cool to see mechanized.
Can't believe the mantis shrimp wasn't mentioned in this video!
You won't beat me. I have a mantis shrimp ready to click the mouse for me. (and a replacement mouse for after)
@nighthawkinlight Harvard Robotics has you covered : th-cam.com/video/If4IURa2Joo/w-d-xo.html
what im learning from a LOT of your videos is that springs were a very important invention
I don't know if you've ever done physics or mechanics before but the world is basically springs and dampers :)
@@jeanrazier2439wheels and seals?
They're what got me hooked on the channel!
ah ah ah noooo springs
@@Monkey_D_Luffy56I’d argue we couldn’t use wheels to their fullest before we invented springs. So both equally important imo.
I love your videos bro!
Keep that super spirit you got man, I really admire your work 😉
Very interesting piece. Well delivered and thoroughly researched.
Thank you.
The over centre mechanism you're looking for in nature can be found in the snipefish.
It has a 4 bar linkage mechanism where the hyoid bone goes over centre, just waiting to be released to capture its prey.
Some nice diagrams in Sarah J. Longo's "Extremely fast feeding strikes are powered by elastic recoil in a seahorse relative, the snipefish, Macroramphosus scolopax" (July 2018 Proceedings of the Royal Society B )
Thank you
STEVE! I am a mechanical engineer who has competed in powerlifting and strongman. I still go to the gym every day, and I can’t tell you how many times I’ve tried to explain these things in the gym! Thank you for continuing to explain awesome principles better than I can.
"...and what things interest you dear child? What do you want to work with when you get older?"
"LEVERAGE!!!"
Hi Steve, the linkage you made reminded me of the stopper on some bottles that use a wire contraption to hold the seal down. It is hard to close at first and gets easier near the end! Great video thank you!
The spring loaded pivots on a hide-away sofa bed extend until the hinge just passes 180° and then hold themselves open. Also the spring loaded switch in a circuit breaker operate the same way.
I found it!!! The Goblin Shark launches its jaw at its prey and uses two of those in tandem. From the 2 minutes of jaw research I just did, it is in the same shape as the green test object you used. It pushes its jaw forward and snaps it down. However, it does not keep the mouth portion in the 'open' position, and instead uses the energy to open it and then snap quickly. This is in conjunction with the alternate mechanism behind it, being always in the 'open' position, ready to snap!!
BIG😊
Sad this didn't get attention though
STEVE THIS GUY FOUND IT LOOK
BUMP
@Langorithmic I'm hoping he sees this as well! :)
i think the mechanism you are talking about is called an "over center mechanism". its also used in vice grips or any storage box latch.
i think teaching tech once did a video on 3d printed examples.
I knew someone would have pointed it out. Over center mechanisms!
Yes, Vise-Grip tools came to mind immediately.
Steve, I'm pretty sure that the principals behind this are similar to why the ball link chains fall with he upward arc over the lip of the container they start in. The first bead pops upward after the lateral force overcomes the friction against the lip and it pushes the bead up allowing the potential to release upward and it finds a balance. Its like a force multiplier at the end of the day!
It's so wild to me how so many of these forces are so deeply interconnected.
It's really cool how the body accomplishes movement in all angles and directions by pulling something.
Best savvy gold rush trick. A tiny bit off topic. The Chinese were chased off Australian gold fields so they set up bath houses and laundries. They sold the miners cheep baths with free laundry. All the miners would get clean and the Chinese would get their gold. Tiny amounts of gold would get trapped in clothing, hair and on the skin. It was too small for the miners to see. The wash water was panned and processed in the night.
The Chinese were also banned from sending the gold back to china so they developed some amazing smuggling tricks. Gold dust in the ink in calligraphy, gold coated with pewter statuettes and containers. One sent eucalyptus oil in one of these disguised gold containers only to get a message back from his herbalist uncle, "Forget the gold send more eucalyptus its worth more". That family got very rich.
Interesting!
Sounds like an obscure fairytale.
@@jayytee8062 Its Australia. even our fairy are new, 1913-20's. Search May Gibbs gum nut babies. But the gold rush reports are very well documented. Sadly one of the rich Chinese families went back to Nanking China days before the Japanese invasion arrived.
as an Australian, this seems fishy. Like the kind of story my dad would tell, except my dad is the sort of bastard who would not use the word "chinese" because he has the racism brainrot. The amount of gold you'd get from this would be absolutely miniscule, surely. Panning an entire miner, no matter how hairy, cannot possibly be a plausible way to get an income and I'm pretty sure that there were other, equally distasteful, yet far far more practical methods of getting money to live by in the i n c r e d i b l y xenophobic colonies
Also, the chinese were more often used as forced labour on our aussie goldfields. Google is giving me no reputable sources on this story so I'm calling bull until proven otherwise.
It's an over center latch. You'll find it in all sorts of mechanisms. Usually, whatever its latching provides the "spring" effect over a very short distance. The effect is used everywhere in nature, but not to create sudden movement like you suggest. Humans use it in the knee joint in order to stand without wasting energy.
The over-centre mechanism is used in a lot of stuff. The example i've been most exposed to is dry powder inhalers. If you crack one of those open you'll find multiple instances of this kind of mechanism coupled with gears, springs, sliders and a lot more!
This is how it is with a chain binder for chaining loads down to lorry beds. It's a lever and it can be quite hard to tighten the chain without using an extension, but once you're almost all the way tight, it gets easier to apply the force as it goes over-center and holds itself into position. Releasing the the binder can be done without leverage fairly easily.
Immediately thought of the "swing top" or "flip top" used on glass bottles! (the little wire mechanism with a plug and rubber gasket used in resealable beer bottles + glass bottles used to serve tap water at restaurants)
No joke, that is used on glass maple syrup bottles here in Canada ;)
The human knee is an example of that bi - stable mechanism. Think about how it stabilizes when you lock your knees, you know that thing they tell you not to do. It allows us to stand requiring very little energy while quickly being able to shift into a more athletic configuration
I came to the comments to see whether anybody else had already brought up this example. Steve gave an open request for this example at about 15:20
This is isn't related, moving your knee into the straight/extended position doesn't require or store any energy.
@@mju135 yes it does, the flexor tendons in your legs are stretched and then very slightly slackened as you extend your legs into that "over center"/"locked" position. This is much more apparent in the legs of ruminants, especially horses, who take advantage of the "locking" effect to rest while standing.
@@mju135 It stores the potential energy of your body weight, try standing with your knees bent at 90 degrees for any length of time. Remember the schoolboy prank of "unlocking" someone else's legs by bumping the back of their knees and having them buckle as that potential energy is released?
The locked knee is an example of an 'over center lock', something also used in some aircraft landing gear. When on the ground, the weight of the aircraft stabilizes the gear, but once airborne, easily overcome by hydraulic or mechanical means. In the video at ~12 minutes, allowing the device to rotate just a few degrees beyond flat would make such a lock.
@stevemould the animal I think uses the stored energy as per your requested example would be the click beetle. It seems to store energy in the neutral state but allows it to be used when needed.
I know a bow hunter and immediately thought if the compound bow. It’s very nice being able to hold draw while waiting for a deer to turn just the right way.
Office Stapler seems like the most directly analogous object that exactly matches the device he was looking for.
Came here to say this. Definitely the office stapler. The spring makes it harder to open until it's completely open and then it stabilizes. Once you start closing it again, it snaps shut.
For the green hinge you printed, the perfect real life example of that mechanism is a flip phone! as you pull the phone open, it resists you up until it is almost all the way open, before finally clicking into the stable open configuration. Then it only takes a tiny amount of pressure applied to the back of the phone before it snaps all the way closed again. It's also basically exactly the same form factor as the little hinge you printed as an example.
came here lookin for this. watching him open and close the thing that looked exactly the shape of a flip phone and opens/closes exactly the same as a flip phone and yelling at the screen "FLIP PHONE"
I thought he was being sarcastic when he nearly held the flip phone looking device up to his ear. "Now where have I seen this mechanism before?" /S
Allways a joy watching your channel
Hi Steve The point of balance you were referring to is generally referred to as being "over-centre". The 'Vice' grips in your tool box in the back shed uses this princple to apply a large force and hold it indefinitely. Cheers
The mechanism with the rubber band is essentially working like an over-center mechanism. A natural example of this can be seen when a weightlifter locks their elbows to hold a barbell over their heads.
Or even just the human knee when standing? Or not?
@@freezingDaniel Yes, any "locked" joint is an example of an over center linkage. The restoring force (the rubber band in Steve's example) is usually gravity (weight of your body over your knee joint, or weight of the weightlifter's weights over the elbow joint).
A bear trap uses this same mechanism. Once something steps on it, it pushed the pivot point below the stable spring point and thus pushes both claws up.
Nope. The trigger plate in the center of a bear trap merely releases the latch which allows the springs to slam the jaws of the trap shut. Without the latch, the trap would simply not stay open. Further, the trap does not store large amounts of force. It simply uses very large springs. It functions exactly like a mouse trap, genius.
@@protoborgYou right, mate? Might want to ease up a bit there
@@protoborg "the trap does not store large amounts of force". OK. "It simply uses very large springs". To do what? Springs store force. That's all they do. Perhaps you can clarify that, genius.
Shot put and other throwing feats are fantastic shows of us storing and utilizing rotational forces.
So you're telling me there is a god...intelligent design. Amazing, thank you so much for going into such great detail as usual, very informative Steve!
3:01 People... trebuchets, onagers, mangonels, and ballistas are *all* types of *CATAPULTS.* The first uses gravity, and the other three use torsion, but they are all *catapults.*
Seriously, wtf is wrong with people!
@@MrDogfish83are you commenting on this comment, or the state of the general public?
Catapult is a very versatile word. A catapult catapults a catapult's missile.
Look, I played Civ V a bunch and they were clearly different things, so, 😝
What about bows, they are basically the same thing, just different shape of the projectile.
Your green folding thing immediately reminded me of a similar mechanism as well. I was once working on an engineering project where we needed a bistable hinge. A small door was open, we needed it to fully snap shut after only nudging it in that direction. In prototyping the design, we ended up tearing apart a lot of eye glasses cases to steal the hinges out of them. As I recall, that's exactly how we sourced the part even for our final build.
Glasses case hinges use a different mechanism than the rubber band on the side of your widget, but they accomplish the same thing. Relatively slow to open, but kind of snaps into its final position, and very quickly releases that energy when you start to close it. I'm surprised I haven't seen anyone else mention it yet! I bet you'd have some fun tearing apart a glasses case to see how that hinge is designed.
I’m happy for you. ;)
Oh yea glasses cases might be it, I haven't seen those in at least a decade, even though I still wear glasses... I just got used to the fact glasses sit on my nose 24/7 unless I'm sleeping, so with every new prescription, I tell the guy to keep the case because I don't need it.
Nice example!
I was reminded a little of setting up a tent where there's a elastic wire that keeps the sticks together. I recognize these mechanics in a lot of products that are "set it up yourself"-type.
The item you have designed at 11:30 exists in nature, all over the place. It is in every compound joint. Look at your knees, if you squat with your femurs are parallel to the ground, it is difficult you can only stay there for a short point of time, but as you get to fully upright, it is easier. Once standing you just need small relatively weak muscles to bend the knee forward to walk.
A super common example: Mason jars. That little snap-down lock on the lid uses this kind of resistance-redirection mechanism.
I feel like the most intuitive example of this I can think of is flicking something with your finger! You build up the pressure of your index finger against your thumb, and then release it suddenly, right?
Yes exactly what I was thinking of!
I was about to make this comment.
Or "popping" your tongue by using suction to hold the tongue to the roof of your mouth until the down force overcomes the suction and releases the stored energy
Also snapping.
That is NOT building pressure. That is overcoming friction. It is much the same way lighting a match works.
Vice grips are the immediate thing I thought of for an example of your mechanism. They can produce tremendous amounts of clamping force because as you squeeze the handles the mechanical advantage skyrockets as it approaches the final clamped position.
The toggle lock on a Luger pistol utilizes some properties of the mechanism you show, although not to the same end. Instead of a difference in force required at different stages of the toggle to store energy, it utilizes the difference in force applied to the toggle based on direction, with a light upwards force being able to unlock it, but any force in the direction of the muzzle forcing it shut even stronger.
There are two animals you need to know about. As impressive as the speeds in air are, moving fast underwater is even more difficult.
Pistol Shrimp - Able to kill small fish with a jet of cavitating water fired out of a specialized claw. This is so fast it produces shrimpoluminescence.
Mantis Shrimp - Similar to the pistol shrimp, except the mechanism of energy storage is a hyperbolic/saddle shaped plate. They also have uniquely high color vision.
*shrimpoluminescence* Hah, funny. But it is the *shock wave of the water hitting itself* in the final stage of cavitation collapse that produce the light. That process is called *sonoluminescence* because of the connection to sound... Which @ConceptualQuanta probably knew, but any others not familiar with the field might be confused and believe "shrimpoluminescence" was a real term.
as a fellow mantis shrimp fan, I must give you the unfortunate news that Mantis Shrimp cannot, in fact, see more colors than us. While they have 12 different types of photoreceptors (4x as many as humans), they use each of these to detect a different color, while human brains can take how red and how green an object is and say "this is yellow."
@@VoidDustMuffin - Some humans have FOUR different kinds of photoreceptors for colors, a condition known as *tetrachromacy* which enables them to see _many more colors_ than normal. But tetrachromacy only occurs in human females, and only if their fathers had red-green color blindness. Once such female is Mila Kunis. All strange, and all true.
@@VoidDustMuffin Would love a source paper for this. While I don't expect the range of colors to be significantly distinct from other animals (NIR to UVA), having the extra sensitivity to specific frequencies allows for the disambiguation of multiple combinations of source colors yielding what we would perceive as a single color. For example
1. Red+Blue is purple, but their average frequency or wavelength would be green, which implies we encode the chord as distinct. There's no reason for me to believe that more color channels does not yield new bitwise color compositions like this with a type of receptor per channel. I also am not implying they perceive only on or off, because neurons are comfortably analog.
2. Most people see two versions of orange light as identical: Orange (single frequency) vs Orange (Red + Yellow). With sufficient distinct receptor spectra profiles within the same region, these could be distinguished.
@@YodaWhatSonoluminescence is the physical process. Shrimpo... refers to shrimp doing it.
Happy to say it's not a term I made up.
See Shrimpoluminescence, American Physical Society, 54th Annual Meeting of the Division of Fluid Dynamics, November 18-20, 2001, Bibcode 2001APS..DFD.EA009V
This is exactly the mechanism of the “worlds highest jumping robot” , the one veritasium made a video about, storing energy with rubber bands and accumulating energy with a small motor
about 12:20 - i think any furniture door has this to stay either open or close while pulling/pushing while in the middle-state. it's more just supportive to opening or closing.
What a great insight! I have discovered from this video that Nature is not only an expert in science but also engineering. The video shows how smartly Nature uses engineering to overcome the physical limitations imposed by science. This video simply opens a door to infinite mysteries of Nature. Not only science, but engineering also needs be learnt from Nature. I think there is more engineering than science in Nature.
A trebuchet is a type of catapult.
I can’t tell if this was a ingenuous ploy for engagement, knowing that people would take to the comments to ‘correct’ him. But either way I’m glad you’re going to get more comments on this video Steve. Great vid
Either it is, *OR* catapults are explicitly bolt throwing crossbows as opposed to ballista which fire balls but are otherwise the same. If onagers are catapults so are mangonels, including trebuchets.
@@mandowarrior123 it is, it wasn’t a sarcastic comment. Apologies if it came across that way. But yes a trebuchet is a catapult, also interestingly a mangonel is a type of trebuchet.
Definitely was :)
But is a revolver a type of pistol then?
@@VikingTeddy Yes
Your common household light/plug socket switch has such a mechanism. The fast action prevents electrical arcing.
yep! 1st thing that came into my mind also. Because I repaired one last Saturday
Thank you for this fascinating comment! I had never even considered before why light and socket switches have such a "harsh" click between on and off
13:43 i have something similar on trailer latch. It's leaver with 2 turning points that are offset. One closer to end gate is pivot for handle (the leaver) and one bit further is pivot for eye that catches the hook on the end gate. It gets harder and harder to pull the leaver until certain point where the points are in line, and then it shuts close as leaver pivot is also offset a bit away from frame, so second stabile position holds it shut. I saw same thing on some jars and other things too.
Another example of that side quest mechanism is used in the office stapler - when you open the handle all the way back to refill the staples into the magazine.
The quick-release levers on bicycle wheels use an over-center cam mecanism.
Another example of the spring-loaded mechanism as found in the piezo lighter is the automatic center punch. It allows you to make dents without a hammer so your drill doesn’t wander.
That's what I was trying to think of! My bicycle pump has an over-centre clasp on it. I'm sure I've also got some gardening or electrical tools almost the exact shape of the demo in the video.
An OTF automatic knife too.
Or spring loaded flight case catches.
there are plants that shoot seeds with all sorts of fun ways they use mechanisms to spread their seeds
most examples of the last mechanism can be considered an over-center linkage. super commonly used concept. I used one in a claw on a competition robot and it held up 25 or so pounds with only 10-15 pounds being applied by a pneumatic cylinder. It was gripping a vertical 2" sch40 pvc pipe for reference
Regarding your "Sidequest" mechanism, which becomes very light at the end and then locks into a stable position that quickly collapses again, think of your own knee. When you introduced the mechanism, it was immediately clear to me. (It came to mind immediately from sports medicine) What I honestly find very funny is that you have not found an example of the mechanism that we use ourselves (sorry for the Bad English)
I'm glad that you brought up compliant mechanisms, I was going to say how awesome it was that the grasshopper's exoskeleton is basically a biological compliant mechanism!
9:14 - The other neat thing about the angle of the (blue) extensor muscle is that it's *perfectly* aligned to prime the spring. I love the double purpose of (1) priming the spring strongly while (2) extending the leg weakly enough for the flexor to hold it.
The mechanical effect you're looking for examples of is present in light switches too. It takes some force to push them up/down until you reach the midway point, then it snaps into place on its own.
That mechanism you are describing reminds me of many things: bicycle stands, power switches for your light or other electric devices.
There actually are crossbows where the latch moves forward to catch the string and is only afterwards forced rearwards to tension it. (One example is the so called "assassin" crossbows where after moving the latch forward to catch the string you use a screw mechanism to draw the latch and string backwards -- Todd Cutler has some good video on those)
The plants that explode for seed dispersal is another example of slowly stored energy released quickly, and is a non-animal but still biologic example. It apparently even uses a cellular hinge mechanism.
"The Energy is stored slowly, delivered quickly"
I like that!
@SteveMould One example of a mechanism like the one at 12:12 you might have been thinking about is the latch of a lidded jar. The ones with a glass lid and a hinge and latch made of wire. The latch flexes while putting pressure on the seal and crosses a point where it holds itself in place.
The beginning of this video made me want you to breakdown the mechanics of baseball pitching so bad!!! It's so incredible, watching it in slow motion -- and also, pitchers are currently facing an injury crisis, the more they optimize for velocity and spin
That's the first thing that came to mind: professional pitchers (baseball and, probably, cricket players as well) have been refining their motion to apply as much force to the ball as possible, for the longest time possible. Your rotator cuff can take a beating if you aren't careful.
The "over center" mechanism you refer to is called "toggle". These are used in suitcase latches, fire sprinklers, some large clamping presses, keyboard switches.
The thing you totally miss in this video is the inertia problem. The reason you can't throw the small marble fast is that the inertia of your own arm/hand is so much more than the marble. Most of the energy you expend is accelerating your own arm. Put that marble on the end of a long lever, you can throw the marble fast despite muscle reaction speed. The grasshopper has all the massive parts (muscle & spring) close to the axis of rotation. Effective inertia is proportional to the SQUARE of the distance from the axis. Only the small leg mass at the tip moves as fast as the working load. For the bow-arrow, only the center of the string moves at arrow speed. The leverage ratio approaches infinity at the moment of arrow release.
Aside from being wrong about suitcase latches (that's more spring tension than an overcenter), fire sprinklers (that's a small glass tube that applies pressure until it is shattered by the heat), and keyboard switches (they don't toggle), you are correct.
@@protoborg I am NOT wrong about some suitcase latches, nor fire sprinklers either. The latches I am referring to are the ones that go over center such as this one:
www.google.com/search?q=tobble+latches&rlz=1CAIEIT_enUS807&oq=tobble+latches&aqs=chrome..69i57.3087j0j7&sourceid=chrome&ie=UTF-8#vhid=vt%3D16/prds%3Dcatalogid:4897673629388163995,gpcid:8491858234117819194,headlineOfferDocid:-5038498684872209881,imageDocid:7171287479730224857,mid:576462452498884126,mno:3,pvo:3,pvt:hg,query:dG9nZ2xlIGxhdGNoZXM,rds:/vs%3D0&vssid=uvpv-713
Look at this image of fire sprinkler heads
www.radfiresprinklers.com/wp-content/uploads/2017/07/Grinnell-sprinkler-heads.jpg
The "1919Niagra" & the "1956 CSB" & others in the photo have toggle mechanisms. The 3 points of the lever are ALMOST in line, so a weak fusible alloy in shear can hold the valve plate shut. Like the grasshopper leg, the toggle is never allowed to go over center.
Regarding keyboard switches (not the cheap "silent" crap that is sold now-days, I'm talking about REAL IBM keyboard), it uses an "over-center" mechanism, like the Cherry switch shown in this video:
th-cam.com/video/3xcJ7m96_aA/w-d-xo.html
The spring tension crosses over the fulcrum point, causing the mechanical advantage to switch signs, just like the suitcase latch I reference. This introduces hysteresis into the mechanism. Instead of contact, the mover is conductive plastic. It gets closer to conductor on circuit board where difference of capacitance is sensed, so there are no contact to get dirty.
@@protoborg You are wrong again. The spring tension of a suitcase latch is held in place specifically because it is an over-center mechanism. An over-center mechanism always involves some kind of tension (a spring) which holds itself in place when the two halves are folded past center, causing the line of force of the tension to be "over center".
Why do you insist on "correcting" everyone so strongly when you are so often wrong in your correction?
Some animals such as horses stand while sleeping by aligning their legs and locking their knees thanks to the tension of their tendons.
I would say it is exactly the same mechanism as described.
For the answer to the bi-stable configuration in nature, look up Venus fly trap mechanics. it uses turgor pressure to slowly build the pressure to reach one state and the bug triggers a reaction that builds a tiny counter pressure to send the state over the energy hump required to snap into the other stable (closed) state!
3:00 "a slingshot, actually a catapult" *shows a trebuchet* | If this was actually intentional I'm impressed!!!
I was about to come say this lmfao. beat me to it
and made me think how a slingshot is actually more of a catapult than a trebuchet is.
I choose to believe that's intentional, because I'm quite bothered by the "mistake" and have to complain about it here in some way.
Engagement?
It has to be. There's no way this man doesn't know the difference.
He's trolling us to get you in the comments, and it worked.
@@AnthonyHarrisTechrat who's trolling who - the creator who correctly depicted a catapult, or the comments that don't know that a trebuchet is a catapult
You might be thinking of the wrist snap bands. They are flat, then you give it a little tap on your wrist, it springs close around it.
Hair clips too.
@@OzAndyify Wrong.
Nope. That uses the resistance to bending of the curve to hold it flat in the perpendicular direction. The metal is also pre-flexed in such a way that it prefers to curl around the long axis. Thus, when it curls along the short axis it is prevented from returning to its natural state. THAT is how a slap bracelet (that's what they are called) works.
Impressive video, sir! Respect