This is absolutely amazing, nice work on everything and I have no doubt you'll have a lot of interest. I commend you on this project I really do personally I'm thinking how amazing it would be scaled up lol.
I've been thinking about one powered by a gas ram that launches golf balls, but I can't quite justify the cost to myself :P Nice K'nex trebuchets, by the way.
@@davideade8692 It would be great to see the pressure and shock waves. Maybe contact the 'Slow-mo guys' or The Backyard Scientist.? They have some high-speed cameras.
Congratulations, excellent work. I'd bet that if you start a gofundme page to scale this up, you could come away with a profit. It would be interesting to see a bowling ball break the sound barrier.
Holy smokes! I can't believe the supersonic report out of this little trebuchet! You should really contact the Guiness Book of World Records with this as it is the first supersonic trebuchet in history. I wish I knew what sort of accuracy you could achieve out of this or a slightly more refined supersonic trebuchet at various distances.
@@jamal69jackson77 a trebuchet is traditionally and technically a device which uses a counterweight to propel a projectile. Because the energy is sources from the elastic potential energy as opposed to gravitational, it wouldn't qualify as a trebuchet. I only mention it because of the comment about the Guinness World Record, they wouldn't be able to classify as such and would instead have to classify it as something else. Catapults and ballistas used torsion in twisted ropes as a means for energy delivery, so I'm not sure exactly what this would be classified as to be perfectly honest, but it wouldn't be a trebuchet :)
My son and I made a trebuchet as his "final year" project. For the "object" we threw 600ml coke bottles... until the police arrived and asked that we stopped using the local park as a practice ground... We never did find one of those bottles as it exceeded expectations and went into the trees... Fin is now finishing his final year in aeronautical engineering and I suppose he'll be boasting that he is a "rocket scientist"... but it all started with...
I've always pondered this, figured I'd try it someday... thank you, because I probably never would've, until now. Sub'd, looking forward to your future achievements.
Im having trouble understanding how the rubber retracts fully to its normal state after only one rotation of the arm. It seems the rubber stretches way further than the circumference of the axle, and the rubber would still be taut upon the trigger release. What am i missing?
The rubber is still under a LOT of tension after the shot. It goes from about 4.5x its rest length, to about 3x its rest length. The tension has to be released by backing off the winch later.
Wow! Finally the YT algorithm showed me this masterpiece! I was running simulations to build a supersonic trebuchet around the same time you posted this video, however I found it to be near impossible (I think my simulations used a counterweight), but hearing that sonic boom was insane. Would love to see some high speed footage of this thing launching!
Tom, I wasn't paying attention when I clicked on this from the side bar, and I assumed UA-cam had simply served me your latest video! Took a few seconds of "hey, that's not his voice"
i wonder why le algorithm is bringing this around again now?? i just got it too.. do you think something happened to get the video back into rotation as it were, or is it showing up based purely off of our own search/subscription activity?? i feel like its something internal and unrelated to our actions as users.
Hey Tom! Love your channel. Yeah, this would be really hard using a counterweight at such a small length scale. If I was trying to do that, my first guess would be to increase the angular stroke to some huge number and run it in a vacuum, but it's maybe possible to do with multiple arms in series? Haven't done any serious study of those machines. Triggering would be very tricky of course.
Agree ... i would think that a 12v wench with a battery would be a much safer proposition... but it wouldn't have fit tje budget unless he could scrounge a used one cheap.
Fantastic! I always love seeing engineering used for interesting stuff, and this is it for sure! Nice job! BTW I have a "fancy" high-speed camera but judging by your surroundings and that odd white stuff on the ground, I gather you're not too close to Florida. ;-)
@@davideade8692 Thanks! You know, I traverse two different worlds with a lot of what I do...the world of engineering, science, math, and then the world of GIT 'ER DONE! The latter, the fabricator types, generally have disdain for degreed engineers because most of the ones they meet are "math heads" who can't even change the oil in their car. What you're showing here is extremely valuable in showing that "all them thar numbers" CAN be important, and sometimes crucial to getting a task accomplished! I'm going to spread your video far and wide and I hope to help you inspire future generations of engineers.
@@markserbu Mark confirmed new Bill Nye the Science Guy, since the old one is broken. I’m a random dude, but this is spot on. I’m in construction, and I don’t have a college degree, but I’m shoulders with some dudes with masters degrees who don’t know which way to turn a screw.
Dude I am loving this way too much :D "Turns out its pretty easy" - and continues with the most awesome optimization procedure that I have ever seen for a mechanical design. Now I wish I had had a lecture in mechanical design optization :P I will definitely look into your data. Doing this in three weeks also seems fairly amazing.
Thanks! To be fair, I had certainly worked on catapults before, and already had a simulation tool written from a previous project. Just hadn't investigated the limits of the concept.
I'm really glad you decided to use LaTeX to describe a latex-driven catachet. Super impressive work. I had also recently started to gather supplies to make such a device but was planning on using just a less efficient simple catapult arm and brute-forcing the ratio between amount of rubber and the payload, with a properly tapered arm. Your design (and the process that went into it) is far more elegant, and the tell-tale supersonic crack on the video of the plywood version is unmistakable and very satisfying.
As an aerospace engineer that graduated in 1997, I am jealous that you young un's get to do all this with such great tools. It looks like playing a video game. Calculating this stuff by hand or even a programmable calculator was not nearly as cool. Those were the days of waiting in line to use the computer room.
You should contact either James the Hacksmith he is in Kitchner, Ontario or Destin from Smarter everyday from US. Love this video thank you for showing the engineering process, wouldn't mind seeing the actual build video if you have it.
I actually did contact Destin about it, but he wasn't interested at all. The Hacksmith is an interesting suggestion though, I think I'll follow that up. Thanks! Unfortunately (or perhaps fortunately, given how messy my shop was at the time) I didn't record the build.
Possibly Gav of the Slo-mo guys. The other option is contacting universitys of some form because of the practical application of physics and maths to make somethng quite tangible. Added in it's portability and I can see this easily as an educational tool for people.
"if you can do this with building blocks and office supplies, what can you do with carbon fiber and tatanium?" waste 250,000 dollars getting crushed like ants in a soda can
Well done David. Loved watching this video. Only one thing made me cringe though, when you were cranking up the springs / rubbers, I kept on thinking, “You are standing in front of a loaded weapon”, and I cringed but took solace from the fact the video was produced meaning you survived safely. Cheers, Brian from NZ.
@@davideade8692 Agree with Brian. The smart alternative would be to load after fully energizing the system. Potential for finger/hand mangling, which is decidedly less final than supersonic projectile to the head. Very interesting design process in this project, which I can't recall seeing anywhere else on YT. Real engineering.
Cool video, and a great result, but I share the safety concerns of the other commenters. This is based on my experience designing and testing hang glider tow releases, where I was aware of a famous Canadian instructor who had lost an eye to a towline break because he used overly elastic rope for the towline bridle. My big concern is structural failure while tensioning the system….especially since wood tends to fail catastrophically. A simple plywood shield (or polycarbonate would be even better), shop safety glasses, and /or a helmet would go a long way to reducing the risks.
@@boots7859 One can simply block the arm with a safety pin(like with the knex model), allowing you to span the rubbers without the arm possibly moving.
i love how you go into the proper engineering process instead of oversimplifying everything and jumping straight into the build like a lot of big youtubers who optimize for mass appeal
Yea, I wish this was an advert for an engineering degree, I've never really seen the engineering design process explained like this, or used so effectively! As markserbu said above, sadly the most common encounter with someone who knows those formulae and the process is the least able to apply them or communicate them effectively! I'm sure you will go on to do great things!
@@trif55 yeah! I really wish I had this guy as one of my professors. the same content is so much less engaging when you're just having formulas read at you
@@MrSurrealKarma simplifying things allows the content to reach a wider audience, which is great in its own right, but i personally enjoy deep dives like this a lot more
A lot of big UA-camrs just guess and do things through trial and error. I'm personally surprised that he did actual engineering and got the results correct on the first try.
It would take me a long time to understand all of this, but I love how you minimized the "hardness" of the design. This is an engineering master's thesis right here. Would love to see what you are working on now.
Now that you've got the object at supersonic speeds how about the more difficult problem of getting it to repeatedly impact a distant stationary object at a precise location?
Yeah, let this guy further develop a military weapon by improving accuracy using shit from your cellar. This sure will come in handy in these times of social revolts and demonstrations….
Slow-Mo Guys, right now! I would love to see that. What a cool project this is, seriously. It sounds like a gunshot almost, or rather, like the crack of a bullet passing at supersonic speed. Amazing work. I'm thinking about building one now.
As a grad student in fluids who's done some control theory, it was incredibly satisfying to see this idea cast as a constrained optimization problem simplified with scaling laws, and to see it work spectacularly. I saw that you even accounted for hysteresis in the rubber! It's awesome to see actual engineering used for this kind of project. Judging by the snow, I'd guess you're not near the LA area, but in case you ever are, I have access to a high speed camera and a small schlieren setup. I'm sure the shockwaves coming off the ball and sling would look incredible during launch
I’m hoping that this was a doctoral thesis. An accredited institution sure as hell should give you credit for this brilliant analysis, modeling and results. Well done!!
Um, this could have been done using high school algebra. OP is just flexing to make his viewers feel dumb. Further: he provides only fuzzy circumstantial evidence of success: no actual measurements. OP is a poor engineer, which is probably why he is chasing YT money instead of, you know, actually working in engineering.
Yeah can you imagine if this could be pulled off in the day without the rubber. The sound alone would make the defenders soil their pants and raise the white flag
As a mechanical engineer myself (thou i oriented towards IoT and automation), this was honestly humiliating. What you have achieved in the given timeframe is pretty respectable!
I think the video doesn't make it clear that I'd already built the model and done a few projects in the trebuchet field before starting this project. Building all that groundwork in a month would be truly ridiculous.
I love how you engineer the engineering. The meta-analysis is great, its like instead of just walking towards a goal (naive approach), or using a map (engineering) rather finding the best tool to select the best map to decide the best way how to get to the goal with the least total effort.
This is amazing! I love how your solution vs. the Smarter Everyday guy's to throwing something over Mach 1 illustrates the difference 10M subscribers make to your design choices.
In fairness to Destin, building one of these to throw a baseball at Mach 1 would cost a fortune. I did a few studies on how scaling affects the cost, and it's essentially linear with the energy. Getting his performance with this design would likely cost $10k or so.
@@Sgrunterundt I expect the linear scaling would break when the parts got large enough to be non-standard sizes, but that happens well above baseball scale.
I'm glad someone else noticed he was being pretty dangerous during the cranking. One thing breaks and his head has a steel ball through it. Cringed the most during the measurement. Like bro if it snaps your hands go bye bye. You can just glue or screw a yard stick to it for measurement.
@@mcfail3450 Well I hate to say it but he's only every posted one video so I hope the worst hasn't happened. It would be 100 times safer to point a gun at yourself while you load it, at least a guns safety mechanism is proven.
@@treOODAI guess you could use a cylinder to load the rubber springs, but not for the final release of energy. It would go too slow. A quick-release energy storage device is necessary, which is basically what those rubber springs are.
THIS IS YOUR ONLY VIDEO ?!!?! I'm honestly so surprised. This has such a good production quality I thought you've been doing this for at least a while. Please post more :D this was awesome and I honestly desire more. Also, if you keep this up, you'll probably eventually get up there in the fun youtube science part along Mykull, Nile, William Osman and his friends and all the big boys
Given the lack of safety controls and the way he kept sticking his hands and face in and around the mechanism, I just assume this thing killed him. My condolences to his family if that's true.
@@arturjogi2667with a firearm, the only thing going a deadly speed is the bullet. Doesn’t mean it’s not deadly. If he had a .22 handgun on the end of the frame pointing towards him while he cranked it up, I think it would be obvious how dangerous that is.
I just got recommended it and if you hit newest comments first you can tell it’s buzzin right now. What I don’t get is what did him and destin collab on? Smarter every day said can’t wait but this guy only has one video and it’s this one from two years ago, and I can’t find anything on SED’s channel.. what gives?
I like the sonic boom. You know positively when Mach is achieved. And a nice deep dive into critical parts before fabrication. And minimal ‘trial and error’.
Amazing how modern engineering allows you to do extraordinary things without using modern materials. It seems to me that something almost as good as this could be built with Renaissance technology, if they'd only known how to design it
Probably, although the efficiency would be much lower, as the sling line would have to be much heavier to work with the fibers they had at the time. The Dyneema string I use for the sling has something like ten times the specific strength of anything that was available in the Renaissance.
@@davideade8692 dyneema is incredible. We use it in high performance sailing and run relatively massive loads on tiny bits of string. Blows my mind on a daily basis.
@@jopo3616 I agree, we need the give the AI the instruction to make it shoot projectiles as fast as possible using any resources it can get it's hands on and of course no robotic laws are implemented ;)
To be honest I was most surprised that the rubber was able to move itself fast enough. Even with such a large motion amplification that the arm and sling give, I somewhat expected the rubber to have too much mass relative to its stored elastic energy. I suppose thats the beauty of the optimization approach - that it quickly guides you to the correct intuition. I am now 100% signing up for the optimization elective at my school!
This was really fun to watch, but it was also nerve wracking. I have a suggestion: When working with a machine that can accelerate a projectile to speeds fast enough to cause injury don't stand in the path of the projectile after it's loaded. For example, I would not load the projectile on the machine until AFTER preloading the rubber bands. Call me a worry wart, but I've seen firearms discharge in all kinds of different situations where they were not supposed to.
Yes higher safety margins are a good idea.. The more times you try it out the more chances for the trebuchet to tip over sideways or timber fastener fail, etc. I'd suggest finding a way to add lateral stability and a way to crank the winch while standing off to the side a few feet. Wonderful work, though!
both he and the camera person clearly exercised some level of caution to not stand directly in the plane of rotation, but I think they got too close to it. the most worrying part in my opinion is the cranking.
It's more dangerous loading it after cause it could rip your hand off. Also the projectile will likely just go over your head and if you watched his head never went directly in front of the projectiles path
For your next assignment, please design a larger version that can cast an object into stationary orbit. We've already seen the big spin, but it's way too expensive. 🙂
Anything you want to launch from the ground into orbit, is like a meteor going into earth at a very bad angle. The projectile itself would burn up, that's the scale of energy to get into orbit BTW
This falls into a huge vat of projects wherein my ambition, and desire, are whelmed over by my impatience, talent, energy, persistence, and other attributes to break the sound barrier. But having spent a month attempting to build trebs and cats, to hurl tennis balls for the pupster to chase and retrieve, I can appreciate the raw awesomeness of your efforts, and final success. As others have noted, the 'thud' is very satisfying. Like an applause from the cosmos.
That was epic, loved it. With a larger budget I'd love to know what the maximum speed possible would be given the current limitations of material science.
I'd love to see you team up with Tom Stanton to make a supersonic flywheel trebuchet and make Spinlaunch look silly. ua-cam.com/video/RVT5i4nhIGs/v-deo.html
Thanks Bob! Yeah, I'd love to see something like what Slow Mo Guys have pointed at it. I bet the shock wave forming around the pouch and then extending down the sling line would look awesome, especially with high humidity. Love your work on Onager, by the way. Glad I finally got to see it in Rantoul last year.
@@davideade8692 : Yeah, I'd love to see this fired on a dark night with a spotlight set up to do shadowgraph imagery of the shock waves, and a good high-speed camera set up to collect the images.
You say "turns out it's pretty easy" and then go completely over my head within the first 2 slides. Thank you for this video David, I loved watching this. Now I need to bust out the Lego and get started on a mini trebuchet :D
Elasticity does not scale proportionally, neither does material strength. So, there are limits on how big you can make it. It's not a trebuchet if you do not use gravity as the force provider, it's really a form of flexion machine. The machine is impressive. What is the mass of the projectile? Is the release of the sling consistent enough to aim and hit a target point consistently? That was an issue for trebuchets and onagers.
exactly, but how long would the arm have to be or is the drop unlimited ,i.e. would you have to dig a pit or elevate it? the weight is going to be falling at 9.81 m/s if it falls straight down. perhaps with an arm of 150m w/ a sling of 240m with a drop of some 30m. one might think the sling motion is chaotic and therefore the projectile would have a large spread pattern great comment
You have a rather soothing voice, a charming personality, and the machine itself looked like a rather outstanding piece of engineering. While I'm about as dumb as a bag of rocks on the design optimisation stuff, it's clear you put in a lot of thought and calculations on the project and the video was a joy to watch as a whole. Excellent content!
This truly fantastic. I too have re-engineered ancient devices (conceptually) to increase efficiency and effect, but what you have created is awe inspiring. I have a couple of suggests/ideas that would make it more powerful and efficient, and I'd be more than happy to share with you if you're interested.
As a fan of siege machinery this is about the coolest one I have seen. Of course watching the guys from Top Gear hurl a car and it presumably destroying a barn was very satisfying as well. 😊. Can’t begin to anywhere understand the math you presented but still very satisfying. Great job! Glad you didn’t take your head off with all the potential energy you produced!!!
Beautiful lesson on how to approach real world optimization problems. Why introduce parameters into a design when one can simply derive them from root constraints like an absolute chad. Great work 👍
That crack is menacing, holy shit! haha Just finished modeling a more traditional trebuchet after I got bored of trying to prototype my design from my Rube Goldberg machine assignment. Think i might use a trebuchet in it, still. But a small one!
Mate this is sooo bloody cool, can't wait to see the collab with you and Destin. Thank you for sharing the drawings/simulations thou, if i were still into making loud noises (use to use a capacitor bank to see how loud I could make components/wire atomically cover the containment box) I'd totally build one 🤣
It's a hybrid of a trebuchet and a catapult Trebuchets are usually powered by a falling weight Catapults by tension springs ( Rope Timber or rubber in modern times ) It's way cool thought
it's so interesting to me how similar the sounds are to a gunshot for what you hear as the sound echoes out. mechanically it's the same factor that causes it, the projectile breaking the sound barrier, but achieved completely differently. you would still then, presumably hear a ballistic snap in the direction the projectile is moving. would love to see a camera put out there to hear it and confirm
I think that a trebuchet, ballista, or mangonel are all catapults, but mangonels are tension and trebuchets are gravity powered. But I would definitely not call this a trebuchet. This machine I would call a mangonel.
@@jamesedwardrichardson2131 I just want to point out that, while you're technically correct that mangonels were tension-powered, it's important to note that, that tension laid in the muscles of the men. Mangonels were not torsion powered, like onagers. They were powered by a group of men, giving the machine a solid pull. Importantly, so were the first trebuchets, the so-called traction trebuchets.
I must always think about how it would have been if this has been around 500-800 years ago, and 25 of these were shooting at high value targets in the army across the field.
Great work! Now that you have proven the concept, the crank effort at the end is another design optimization for scaled production. In industry we always design to 50% engine capacity so that if we have to step outside job parameters we don’t break the system.
I achieved mach2 with nothing but a car inner tube back in 1988. Cut the whole thing into a 1 inch wide strip, tied one end to a power pole and walked the other end about 400m up the road. It was shocking. Less than half a second to get well past the pole. It touched a parked cars wing mirror about 50m past the pole, which exploded into tiny fragments of glass and metal. A hard grade of nylon monofilament works better than rubber as a tension spring. More energy storage per mass, and less hysteresis.
Amazing process to get to an amazing result. I work with computers for a living and it's rewarding in many ways, but not in the visceral 'I could easily land on the 'List of Inventors Killed by Their Own Inventions' page on wikipedia' kind of way. Quick technical question, the release point looked reasonably consistent across all of the force regimes you demonstrated in the video, is it a property of the geometry? Also did you come up with the release mechanism? I thought it was incredibly clever.
Yes! Sort of. Scaling up the puller force by a constant factor does not change the geometry of the throw... in a frictionless vacuum. Gravity doesn't scale, so its contribution becomes less important at higher speed. Air resistance scales properly over a wide range of subsonic speeds, but there's a discontinuity in the trans-sonic regime. The gravity effects are too small to be important here, but the release finger angle must be adjusted slightly when moving between subsonic and supersonic flow regimes. I didn't come up with the concept of the release mechanism, it's one of the standard ways mechanical releases are built. I did come up with this specific implementation. It was designed for a much larger machine, and has a safe holding force of 15kN (FoS=5), which is enormous overkill here.
@@jcims Sorry, there's an important omission in the previous comment. There are two important mechanisms that alter the drag coefficient (and thus ruin scaling). The first is trans-sonic flow, as I mentioned. The second is the onset of turbulence, which for a smooth sphere like we have here causes a sudden drop in drag coefficient around Re = 3*10^5. Coincidentally, because this sphere is fairly small (relative to the dynamic viscosity of air), the drop in drag coefficient doesn't happen before the onset of trans-sonic flow. This effect would be important with a larger sphere.
Range? Edit: gUn cONtRoL 😢😭!!! Three weeks. Dang! It takes me twice that long to build an AR-15 to sell to the Mexican cartel. Ha Ha, I didn't write which cartel so the Feds don't know whether to prosecute me or give me a grant and small business loan.
Reminds me of the old "Fibonacci 540" chunker design (540 for the range of motion in the throw). I think they found it too unpredictable an later returned to a sub-180 degree arm stroke. Very nice job on the engineering!
Longer strokes do hurt repeatability, and this is made worse by the proportionally high drag and compliance in punkin chunkin machines. But this machine would have about 8MJ throw energy if scaled to punkin chunker size, so drag doesn't matter very much here.
If he is using a 3/8 in steel ball - tha's around 3.5 g, at the speed of 450 m/s it has about 350 Joules at launch, for comparison, average 9mm bullet muzzle energy is around 500 J
I don't think it would be useful for hunting pheasants but hey it is a pretty AWESOME work of engineering. Great work! :) You have GOT to get some high speed footage!
The design optimization study is great to see and the musings on the creakines of wood just wonderful, thank you for this magnificent video and design, it is inspiring to say the least.
Hey, any pointers where can I read up on thinking behind these dimensionless groups, building the unknown function, the scaling tricks? I'd like to learn about these "modern engineering concepts" that my university never told me about.
Hmm... well, I learned about the Pi theorem in a 2nd year fluid dynamics course, the scaling tricks probably came from a first year physics course. The rest is just putting them together, and the only modern part is using a computer to run the experiments. Get strong with the fundamentals. When they become an integral part of your mental toolkit, you'll be able to start combining them like this.
I think this would be a "catapult" by WCPCA rules. Trebuchets are gravity/weight powered just by definition. That's just semantics though, still an awesome catapult!
Yeah the WCPCA would call it an Unlimited Catapult, I believe. Mine is a Traction Treb. This one could be as well, even though they are still unlimited catapults in the wcpca.
Well done David! Hope you are working in a capacity that allows you utilized your talents. Reminds me of when I was a young engineer contemplating a supersonic RC airplane. Didn’t have the technology to pull that off at home, but did get to work on a Mach 10 hypersonic vehicle at work.
How did you get the rubber for this, that’s my biggest obstacle right now, started developing my own one of these for a larger projectile, but I must be a decent engineer, because I arrived at a very similar arm geometry to yours, it’s convenient as I can just look at how you did the frame, but I can’t for the life of me figure out how to get enough elastic for the force I need. My aim is to throw around 60g at 130m/s
Very well done! Should the need ever arrive, it's possible to replace the rubber bands with an electric motor with a gearbox and a variable cam to maintain a strong and steady yet accelerating pull on the arm.
That's insane. I would expect a mechanical device to barely break the sound barrier, not going nearly 100m/s over the speed of sound. Your work is truly impressive.
Uh... purely mechanical whips have been breaking the sound barrier for at least centuries. Possibly millennia? I wouldn't be surprised if you could attach a small ball bearing to the end of a bullwhip and have it break free at supersonic speeds. Kinda simplify this whole thing.
*THIS is very cute.* The video is amateurish, but the lad is adorable, he is doing a good job. But WHERE his protective gear, when he is working with high tensions? A failure could have easily maimed or killed the lad.
![[UA] NAVI проти G2 Esports | Blast Premier Fall Final](http://i.ytimg.com/vi/QWlIm4FGESQ/mqdefault.jpg)
This is going to be fun. Looking forward to working with you.
Looking forward to seeing the video!
@@moldy_banana5015 Beware the foreskin walker 😳🚬 It took my dog 🐕
Heck yes supersonic trebuchet vs supersonic baseball needs to happen!
How fun!
Can't wait for the vid!
This is awesome. I remember building a ~2 foot tall trebuchet out of KNEX back in the 90's as a kid. This is pure nostalgia right here
Nice! I spent so much time with KNEX as a kid.
the knex got me lol as a 90's kid
'90s *
This is absolutely amazing, nice work on everything and I have no doubt you'll have a lot of interest. I commend you on this project I really do personally I'm thinking how amazing it would be scaled up lol.
I've been thinking about one powered by a gas ram that launches golf balls, but I can't quite justify the cost to myself :P Nice K'nex trebuchets, by the way.
@@davideade8692 It would be great to see the pressure and shock waves. Maybe contact the 'Slow-mo guys' or The Backyard Scientist.? They have some high-speed cameras.
Amazing. So very well explained and boy, how well articulated. Props for that and thank you!
Why your channel have just 1 video
Mankind need more of your works
Congratulations, excellent work. I'd bet that if you start a gofundme page to scale this up, you could come away with a profit. It would be interesting to see a bowling ball break the sound barrier.
In all my life I never thought I'd hear a piece of metal fly as fast as a firearm only using rubber bands.
Holy smokes! I can't believe the supersonic report out of this little trebuchet! You should really contact the Guiness Book of World Records with this as it is the first supersonic trebuchet in history. I wish I knew what sort of accuracy you could achieve out of this or a slightly more refined supersonic trebuchet at various distances.
if only it were actually a trebuchet...
@@JamesManukonga well it certainly seems to be one, I don't know what you consider makes it "not a trebuchet".
@@jamal69jackson77 a trebuchet is traditionally and technically a device which uses a counterweight to propel a projectile. Because the energy is sources from the elastic potential energy as opposed to gravitational, it wouldn't qualify as a trebuchet. I only mention it because of the comment about the Guinness World Record, they wouldn't be able to classify as such and would instead have to classify it as something else. Catapults and ballistas used torsion in twisted ropes as a means for energy delivery, so I'm not sure exactly what this would be classified as to be perfectly honest, but it wouldn't be a trebuchet :)
@@JamesManukonga thanks for the explanation, I understand now.
If only I had stayed awake during that math class.
This dude is like the styropyro of classical mechanics
My son and I made a trebuchet as his "final year" project. For the "object" we threw 600ml coke bottles... until the police arrived and asked that we stopped using the local park as a practice ground... We never did find one of those bottles as it exceeded expectations and went into the trees... Fin is now finishing his final year in aeronautical engineering and I suppose he'll be boasting that he is a "rocket scientist"... but it all started with...
I've always pondered this, figured I'd try it someday... thank you, because I probably never would've, until now.
Sub'd, looking forward to your future achievements.
Great job, great idea 👍
If only the medieval period had this type of machine.
absolutely brilliant. except for the missing eye protection next to the tensioned rubber (and loaded/strained trebuchet!) ;-)
I'm curious if there might be a way to speed up the winding process without sacrificing much.
An entirely rubber powered machine capable of throwing a .50" steel ball faster than the speed of sound. I wonder when this will be regulated.
Okay now make a Hypersonic Trebuchet.
Exactly what I was saying
Im having trouble understanding how the rubber retracts fully to its normal state after only one rotation of the arm. It seems the rubber stretches way further than the circumference of the axle, and the rubber would still be taut upon the trigger release. What am i missing?
The rubber is still under a LOT of tension after the shot. It goes from about 4.5x its rest length, to about 3x its rest length. The tension has to be released by backing off the winch later.
Subbed, great video !!
Wow! Finally the YT algorithm showed me this masterpiece! I was running simulations to build a supersonic trebuchet around the same time you posted this video, however I found it to be near impossible (I think my simulations used a counterweight), but hearing that sonic boom was insane. Would love to see some high speed footage of this thing launching!
Love your content Tom, thanks for putting out quality content!
Tom, I wasn't paying attention when I clicked on this from the side bar, and I assumed UA-cam had simply served me your latest video! Took a few seconds of "hey, that's not his voice"
i wonder why le algorithm is bringing this around again now?? i just got it too.. do you think something happened to get the video back into rotation as it were, or is it showing up based purely off of our own search/subscription activity??
i feel like its something internal and unrelated to our actions as users.
@@snarevox Just found this today and super glad
Hey Tom! Love your channel. Yeah, this would be really hard using a counterweight at such a small length scale. If I was trying to do that, my first guess would be to increase the angular stroke to some huge number and run it in a vacuum, but it's maybe possible to do with multiple arms in series? Haven't done any serious study of those machines. Triggering would be very tricky of course.
Can't believe I'm just seeing this. This is rad. The crack when it fires is wild
same
looks like there was another wave of recommendations of this video, really glad I came across it because it's a masterpiece
Do a video togetther that would be so cool
so cool to see you seeing this
Yknow, whem math is mathing
"An exciting new way to convert time and money into heat and noise" is a really outstanding phrase
Ah so this is how it was before supersonic missiles was invented
Like Bitcoin
time stamp?
I can’t get over how dangerous being at the business end of this thing cranking up that much potential energy is.
I know! where are the safety squints!
Then he touches it lol.
Loaded it before cranking too. 5he c4ank should maybe be at the other end lolol
Agree ... i would think that a 12v wench with a battery would be a much safer proposition... but it wouldn't have fit tje budget unless he could scrounge a used one cheap.
"12 volt wench"? So that's what they call those now...
Hey David! We specialize in capturing super-sonic object with our high-speed cameras. We'd be happy to get some incredible footage of this!
Hurray! Have been waiting for this ever since @davideade8692 posted the video first.
Let's go guys! Make this happen 💪🏻🙌🏻@@johnsimons92
Love your channel guys!
So incredible that it's powered by rubber! JoergSprave would be proud!
I immediately produced a deep belly laugh when I heard that first supersonic crack.
AAHA HA HA HA!
let me show you its features
So I added a bunch of pulleys here, and bualah hOAHOAHOAHOA WE GOT HUAHUAHOA A 9MM SPEED COMPARABLE handheld trebuchet legolini
Joerg, we would like one with a magazine and a pull back to reload mechanism please
Maybe a sight for targeting high value targets on the battle field
Fantastic! I always love seeing engineering used for interesting stuff, and this is it for sure! Nice job! BTW I have a "fancy" high-speed camera but judging by your surroundings and that odd white stuff on the ground, I gather you're not too close to Florida. ;-)
Thanks Mark! Love your work, by the way. Unfortunately, you're correct about the white stuff - I'm a long way from Florida.
@@davideade8692 Thanks! You know, I traverse two different worlds with a lot of what I do...the world of engineering, science, math, and then the world of GIT 'ER DONE! The latter, the fabricator types, generally have disdain for degreed engineers because most of the ones they meet are "math heads" who can't even change the oil in their car. What you're showing here is extremely valuable in showing that "all them thar numbers" CAN be important, and sometimes crucial to getting a task accomplished! I'm going to spread your video far and wide and I hope to help you inspire future generations of engineers.
@@markserbu Mark confirmed new Bill Nye the Science Guy, since the old one is broken.
I’m a random dude, but this is spot on. I’m in construction, and I don’t have a college degree, but I’m shoulders with some dudes with masters degrees who don’t know which way to turn a screw.
I'm in Florida, but I have nothing interesting to film. Unless you want to film various fruits being shot with a pellet gun lol
A compliment from Mark Serbu - *Nicholas Cage Voice* Thats high praise 😎
Dude I am loving this way too much :D "Turns out its pretty easy" - and continues with the most awesome optimization procedure that I have ever seen for a mechanical design. Now I wish I had had a lecture in mechanical design optization :P I will definitely look into your data. Doing this in three weeks also seems fairly amazing.
Thanks! To be fair, I had certainly worked on catapults before, and already had a simulation tool written from a previous project. Just hadn't investigated the limits of the concept.
@@davideade8692 That sounds realistic. Still amazing work!
I'm really glad you decided to use LaTeX to describe a latex-driven catachet. Super impressive work. I had also recently started to gather supplies to make such a device but was planning on using just a less efficient simple catapult arm and brute-forcing the ratio between amount of rubber and the payload, with a properly tapered arm. Your design (and the process that went into it) is far more elegant, and the tell-tale supersonic crack on the video of the plywood version is unmistakable and very satisfying.
As an aerospace engineer that graduated in 1997, I am jealous that you young un's get to do all this with such great tools. It looks like playing a video game. Calculating this stuff by hand or even a programmable calculator was not nearly as cool. Those were the days of waiting in line to use the computer room.
You should contact either James the Hacksmith he is in Kitchner, Ontario or Destin from Smarter everyday from US. Love this video thank you for showing the engineering process, wouldn't mind seeing the actual build video if you have it.
I second the Destin recommendation
I actually did contact Destin about it, but he wasn't interested at all. The Hacksmith is an interesting suggestion though, I think I'll follow that up. Thanks!
Unfortunately (or perhaps fortunately, given how messy my shop was at the time) I didn't record the build.
Possibly Gav of the Slo-mo guys.
The other option is contacting universitys of some form because of the practical application of physics and maths to make somethng quite tangible. Added in it's portability and I can see this easily as an educational tool for people.
Definately contact Smarter Everyday!
Superb work, absolutely. Maths and design, you got brilliant future where ever you wanna build it. Go for it!
The Slingshot Channel needs to see this one!
"if you can do this with building blocks and office supplies, what can you do with carbon fiber and tatanium?" waste 250,000 dollars getting crushed like ants in a soda can
Well done David. Loved watching this video.
Only one thing made me cringe though, when you were cranking up the springs / rubbers, I kept on thinking, “You are standing in front of a loaded weapon”, and I cringed but took solace from the fact the video was produced meaning you survived safely.
Cheers, Brian from NZ.
IRL plot armor
Thank you for a civil comment about a real safety concern. The issue is rather nuanced, but I support your recommendation not to do it this way.
@@davideade8692 Agree with Brian. The smart alternative would be to load after fully energizing the system. Potential for finger/hand mangling, which is decidedly less final than supersonic projectile to the head. Very interesting design process in this project, which I can't recall seeing anywhere else on YT. Real engineering.
Cool video, and a great result, but I share the safety concerns of the other commenters.
This is based on my experience designing and testing hang glider tow releases, where I was aware of a famous Canadian instructor who had lost an eye to a towline break because he used overly elastic rope for the towline bridle.
My big concern is structural failure while tensioning the system….especially since wood tends to fail catastrophically.
A simple plywood shield (or polycarbonate would be even better), shop safety glasses, and /or a helmet would go a long way to reducing the risks.
@@boots7859 One can simply block the arm with a safety pin(like with the knex model), allowing you to span the rubbers without the arm possibly moving.
i love how you go into the proper engineering process instead of oversimplifying everything and jumping straight into the build like a lot of big youtubers who optimize for mass appeal
Yea, I wish this was an advert for an engineering degree, I've never really seen the engineering design process explained like this, or used so effectively! As markserbu said above, sadly the most common encounter with someone who knows those formulae and the process is the least able to apply them or communicate them effectively! I'm sure you will go on to do great things!
@@trif55 yeah! I really wish I had this guy as one of my professors. the same content is so much less engaging when you're just having formulas read at you
You're kinda making that sound like a bad thing, the simplification.
@@MrSurrealKarma simplifying things allows the content to reach a wider audience, which is great in its own right, but i personally enjoy deep dives like this a lot more
A lot of big UA-camrs just guess and do things through trial and error. I'm personally surprised that he did actual engineering and got the results correct on the first try.
It would take me a long time to understand all of this, but I love how you minimized the "hardness" of the design. This is an engineering master's thesis right here. Would love to see what you are working on now.
Now that you've got the object at supersonic speeds how about the more difficult problem of getting it to repeatedly impact a distant stationary object at a precise location?
i like that idea!
lol
Yeah, let this guy further develop a military weapon by improving accuracy using shit from your cellar. This sure will come in handy in these times of social revolts and demonstrations….
@@JoseRodriguez-go5do Shut up "Jose Rodriguez"
mate.... a gun is cheaper and more effective. This would have 0 impact on the issues you named.
That's pretty amazing
No u
Hey bobby love the videos
@@zenddoor ?
Slow-Mo Guys, right now! I would love to see that. What a cool project this is, seriously. It sounds like a gunshot almost, or rather, like the crack of a bullet passing at supersonic speed. Amazing work. I'm thinking about building one now.
As a grad student in fluids who's done some control theory, it was incredibly satisfying to see this idea cast as a constrained optimization problem simplified with scaling laws, and to see it work spectacularly. I saw that you even accounted for hysteresis in the rubber! It's awesome to see actual engineering used for this kind of project. Judging by the snow, I'd guess you're not near the LA area, but in case you ever are, I have access to a high speed camera and a small schlieren setup. I'm sure the shockwaves coming off the ball and sling would look incredible during launch
Maybe you could make your own trebuchet and shoot a slow motion video. Would love to see that if you ever have a chance.
Seeing that iron ring in his right-hand pinky, I'm guessing he's in Canada. (en.wikipedia.org/wiki/Iron_Ring)
Thanks! I'm quite far from LA, as Pascal correctly inferred, but I'll keep you in mind if the opportunity comes up.
I’m hoping that this was a doctoral thesis. An accredited institution sure as hell should give you credit for this brilliant analysis, modeling and results. Well done!!
Um, this could have been done using high school algebra. OP is just flexing to make his viewers feel dumb. Further: he provides only fuzzy circumstantial evidence of success: no actual measurements. OP is a poor engineer, which is probably why he is chasing YT money instead of, you know, actually working in engineering.
@@railgap Columbus faced the same naysayers when he stood an egg on its end.. who else has built a supersonic trebuchet?
A doctoral thesis? More like a bachelors. Maybe a masters but i doubt it.
@@test5093 Trolls. Keeping the Internet entertaining since 1995.
@@Kayaz48 I'm quite serious. Do you have a degree?
Wow the way it breaks the sound barrier is incredible. Thank you for building this!
It sounds like a small cannon. Powered by a rubber band.
Brings a whole new meaning to "You'll shoot your eye out."
Yeah can you imagine if this could be pulled off in the day without the rubber. The sound alone would make the defenders soil their pants and raise the white flag
As a mechanical engineer myself (thou i oriented towards IoT and automation), this was honestly humiliating. What you have achieved in the given timeframe is pretty respectable!
I think the video doesn't make it clear that I'd already built the model and done a few projects in the trebuchet field before starting this project. Building all that groundwork in a month would be truly ridiculous.
I love how you engineer the engineering. The meta-analysis is great, its like instead of just walking towards a goal (naive approach), or using a map (engineering) rather finding the best tool to select the best map to decide the best way how to get to the goal with the least total effort.
That sounds like more work lol
Work smart, not hard 😉
@@PeanutPirate1 Do neither. That gets you into Elon Musk territory. Trust me.
That is some PROPER engineering. Fantastic job.
I know it's been a while, but I'm sure the Slow-Mo Guys would love something like this!
Came here to say the same thing this would be perfect.
This is amazing! I love how your solution vs. the Smarter Everyday guy's to throwing something over Mach 1 illustrates the difference 10M subscribers make to your design choices.
In fairness to Destin, building one of these to throw a baseball at Mach 1 would cost a fortune. I did a few studies on how scaling affects the cost, and it's essentially linear with the energy. Getting his performance with this design would likely cost $10k or so.
I wonder if Destin would be available to use his equipment to film your machine... Anyone know how to ask him?
@@davideade8692 looking at his contraption this would be cheaper
@@davideade8692 Only linear with energy? I'd expect much worse.
@@Sgrunterundt I expect the linear scaling would break when the parts got large enough to be non-standard sizes, but that happens well above baseball scale.
Loved this! Buy yourself a blast shield and some safety goggles, then make more videos! I'd happily watch.
I'm glad someone else noticed he was being pretty dangerous during the cranking. One thing breaks and his head has a steel ball through it. Cringed the most during the measurement. Like bro if it snaps your hands go bye bye. You can just glue or screw a yard stick to it for measurement.
@@mcfail3450 Well I hate to say it but he's only every posted one video so I hope the worst hasn't happened. It would be 100 times safer to point a gun at yourself while you load it, at least a guns safety mechanism is proven.
As a student of ballistics for 30 years, I had no idea that was possible. Great explanation of the math application.
Consider that when someone cracks a whip, it's breaking the sound barrier.
"I like to shoot things and math with squiggly lines impresses me"
I wonder if you could use a hydraulic cylinder to leverage the same output..
No wonder you're still a student
@@treOODAI guess you could use a cylinder to load the rubber springs, but not for the final release of energy. It would go too slow. A quick-release energy storage device is necessary, which is basically what those rubber springs are.
This is the old youtube quality in more modern times. Love it
THIS IS YOUR ONLY VIDEO ?!!?!
I'm honestly so surprised. This has such a good production quality I thought you've been doing this for at least a while. Please post more :D this was awesome and I honestly desire more. Also, if you keep this up, you'll probably eventually get up there in the fun youtube science part along Mykull, Nile, William Osman and his friends and all the big boys
Given the lack of safety controls and the way he kept sticking his hands and face in and around the mechanism, I just assume this thing killed him. My condolences to his family if that's true.
@@speedweasel Wohin Corporation
@@speedweasel ye i was anxious watching him touch that ball in armed supersonic trebuchet
It's a trebuchet. The only part going a deadly speed is the ball and string
@@arturjogi2667with a firearm, the only thing going a deadly speed is the bullet. Doesn’t mean it’s not deadly.
If he had a .22 handgun on the end of the frame pointing towards him while he cranked it up, I think it would be obvious how dangerous that is.
How on Earth, has this video not taken off as fast and hard as those shots? Brilliantly done!
ive been getting some banger engineering vids recently on reccomended
I just got recommended it and if you hit newest comments first you can tell it’s buzzin right now. What I don’t get is what did him and destin collab on? Smarter every day said can’t wait but this guy only has one video and it’s this one from two years ago, and I can’t find anything on SED’s channel.. what gives?
@@agentmueller The SED collab is still in the works. It's a big project. I guarantee you'll like it.
@@davideade8692 Can't wait! Destin is an awesome guy, really hope your channel can grown even more with his help
@@davideade8692 Can't wait!
I like the sonic boom. You know positively when Mach is achieved.
And a nice deep dive into critical parts before fabrication. And minimal ‘trial and error’.
Amazing how modern engineering allows you to do extraordinary things without using modern materials. It seems to me that something almost as good as this could be built with Renaissance technology, if they'd only known how to design it
Probably, although the efficiency would be much lower, as the sling line would have to be much heavier to work with the fibers they had at the time. The Dyneema string I use for the sling has something like ten times the specific strength of anything that was available in the Renaissance.
Design a Supersonic Trebuchet with Renaissance materials? Sounds like a problem only a super AI could solve.
@@davideade8692 dyneema is incredible. We use it in high performance sailing and run relatively massive loads on tiny bits of string. Blows my mind on a daily basis.
@@jopo3616 I agree, we need the give the AI the instruction to make it shoot projectiles as fast as possible using any resources it can get it's hands on and of course no robotic laws are implemented ;)
@@davideade8692 what sort of forces are experienced by the line?
0:05 Not a trebuchet. That is a mangonel. A trebuchet uses a weight to provide energy, not a tortionary material.
To be honest I was most surprised that the rubber was able to move itself fast enough. Even with such a large motion amplification that the arm and sling give, I somewhat expected the rubber to have too much mass relative to its stored elastic energy. I suppose thats the beauty of the optimization approach - that it quickly guides you to the correct intuition. I am now 100% signing up for the optimization elective at my school!
You can get double the speed from the rubber by using a pulley system
@@ddexter8723can you quadruple it with a double pulley?
@@williamchamberlain2263 if you set up a quad pulley... noble peace prize right there. truly the peak of all engineering feats.
@@derekgross7852 Who was it that said there is nothing as practical as a good theory?
why would u be surprised? small rubber balloons pop with supersonic speed without any engineering.
This is remarkable. The report is even better!
This was really fun to watch, but it was also nerve wracking. I have a suggestion: When working with a machine that can accelerate a projectile to speeds fast enough to cause injury don't stand in the path of the projectile after it's loaded. For example, I would not load the projectile on the machine until AFTER preloading the rubber bands. Call me a worry wart, but I've seen firearms discharge in all kinds of different situations where they were not supposed to.
Yes, a ball like that has more "muzzle" energy than many pistol bullets.
Yes higher safety margins are a good idea.. The more times you try it out the more chances for the trebuchet to tip over sideways or timber fastener fail, etc. I'd suggest finding a way to add lateral stability and a way to crank the winch while standing off to the side a few feet. Wonderful work, though!
both he and the camera person clearly exercised some level of caution to not stand directly in the plane of rotation, but I think they got too close to it. the most worrying part in my opinion is the cranking.
I've honestly been watching carefully and saw that he was off the axis of the trebuchet at all times when it was loaded, but the criticism is fair.
It's more dangerous loading it after cause it could rip your hand off. Also the projectile will likely just go over your head and if you watched his head never went directly in front of the projectiles path
I love the fact that you actually talk about the math behind it, too few engineering youtubers do that
Never thought of optimizing an engineering problem with a difficulty function. Beautiful modelling work!
Great engineering feat. Would love to see some slo-mo and impacts of the projectile.
I'm guessing it is not relatively accurate over long distances.
For your next assignment, please design a larger version that can cast an object into stationary orbit. We've already seen the big spin, but it's way too expensive. 🙂
You need a secondary push from orbit so a Trebuchet shooting a Trebuchet shooting a payload
@@EnderRobber101 I bet you could get funding from elon musk if it launched a tesla into space.
@@alexCh-ln2gw basically the concept of spin lauch
Imagine seeing a thousand people cranking a huge wheel to toss a rocket into orbit 🤣
Anything you want to launch from the ground into orbit, is like a meteor going into earth at a very bad angle. The projectile itself would burn up, that's the scale of energy to get into orbit BTW
This falls into a huge vat of projects wherein my ambition, and desire, are whelmed over by my impatience, talent, energy, persistence, and other attributes to break the sound barrier. But having spent a month attempting to build trebs and cats, to hurl tennis balls for the pupster to chase and retrieve, I can appreciate the raw awesomeness of your efforts, and final success. As others have noted, the 'thud' is very satisfying. Like an applause from the cosmos.
The first time I read this I thought you were hurling cats. I'd pay to see that.
This is fantastic. The trebuchet community will be very excited. Thanks!
That was epic, loved it. With a larger budget I'd love to know what the maximum speed possible would be given the current limitations of material science.
I'd love to see you team up with Tom Stanton to make a supersonic flywheel trebuchet and make Spinlaunch look silly.
ua-cam.com/video/RVT5i4nhIGs/v-deo.html
Impressive! It would be cool to view with super high speed video. I wonder how far the shots went.
Thanks Bob! Yeah, I'd love to see something like what Slow Mo Guys have pointed at it. I bet the shock wave forming around the pouch and then extending down the sling line would look awesome, especially with high humidity. Love your work on Onager, by the way. Glad I finally got to see it in Rantoul last year.
@@davideade8692 : Yeah, I'd love to see this fired on a dark night with a spotlight set up to do shadowgraph imagery of the shock waves, and a good high-speed camera set up to collect the images.
You say "turns out it's pretty easy" and then go completely over my head within the first 2 slides. Thank you for this video David, I loved watching this.
Now I need to bust out the Lego and get started on a mini trebuchet :D
I got completely nerd sniped by your design process. Absolutely love that parametric optimisation design approach.
Elasticity does not scale proportionally, neither does material strength. So, there are limits on how big you can make it. It's not a trebuchet if you do not use gravity as the force provider, it's really a form of flexion machine. The machine is impressive. What is the mass of the projectile? Is the release of the sling consistent enough to aim and hit a target point consistently? That was an issue for trebuchets and onagers.
exactly, but how long would the arm have to be or is the drop unlimited ,i.e. would you have to dig a pit or elevate it? the weight is going to be falling at 9.81 m/s if it falls straight down. perhaps with an arm of 150m w/ a sling of 240m with a drop of some 30m.
one might think the sling motion is chaotic and therefore the projectile would have a large spread pattern
great comment
@@nickg8424 The answers are far too detailed for a you tube comment. Look for catapult message boards on Redit or Facebook.
@@DARIVSARCHITECTVS thx
Trebuchets, onagers and ballistas are all just different types of catapult.
You have a rather soothing voice, a charming personality, and the machine itself looked like a rather outstanding piece of engineering. While I'm about as dumb as a bag of rocks on the design optimisation stuff, it's clear you put in a lot of thought and calculations on the project and the video was a joy to watch as a whole. Excellent content!
This truly fantastic.
I too have re-engineered ancient devices (conceptually) to increase efficiency and effect, but what you have created is awe inspiring. I have a couple of suggests/ideas that would make it more powerful and efficient, and I'd be more than happy to share with you if you're interested.
As a fan of siege machinery this is about the coolest one I have seen. Of course watching the guys from Top Gear hurl a car and it presumably destroying a barn was very satisfying as well. 😊. Can’t begin to anywhere understand the math you presented but still very satisfying. Great job! Glad you didn’t take your head off with all the potential energy you produced!!!
Beautiful lesson on how to approach real world optimization problems. Why introduce parameters into a design when one can simply derive them from root constraints like an absolute chad.
Great work 👍
That crack is menacing, holy shit! haha
Just finished modeling a more traditional trebuchet after I got bored of trying to prototype my design from my Rube Goldberg machine assignment. Think i might use a trebuchet in it, still. But a small one!
Mate this is sooo bloody cool, can't wait to see the collab with you and Destin.
Thank you for sharing the drawings/simulations thou, if i were still into making loud noises (use to use a capacitor bank to see how loud I could make components/wire atomically cover the containment box) I'd totally build one 🤣
Funny you mention this, as I'm working on refurbishing my old pulsed power system at the moment. 25kJ at 16kV :D
@@davideade8692 Man, here I was thinking my 1.5kJ 1kV capacitor bank was loud, I'll bet that thing could make you go deaf! 25kJ, good lord...
It's a hybrid of a trebuchet and a catapult
Trebuchets are usually powered by a falling weight
Catapults by tension springs ( Rope Timber or rubber in modern times )
It's way cool thought
it's so interesting to me how similar the sounds are to a gunshot for what you hear as the sound echoes out. mechanically it's the same factor that causes it, the projectile breaking the sound barrier, but achieved completely differently. you would still then, presumably hear a ballistic snap in the direction the projectile is moving. would love to see a camera put out there to hear it and confirm
Technically, I suppose that wood is carbon fiber.
I love that you go more in depth with the math and modeling than most build channels on youtube! Good way to stand out!
if im not mistaken trebuchets are powered by gravity via a counterweight, and catapults are powered via tension. Great video either way!
Thank you! I though I was the only person that caught that detail.
I think that a trebuchet, ballista, or mangonel are all catapults, but mangonels are tension and trebuchets are gravity powered. But I would definitely not call this a trebuchet. This machine I would call a mangonel.
@@jamesedwardrichardson2131 I just want to point out that, while you're technically correct that mangonels were tension-powered, it's important to note that, that tension laid in the muscles of the men. Mangonels were not torsion powered, like onagers. They were powered by a group of men, giving the machine a solid pull. Importantly, so were the first trebuchets, the so-called traction trebuchets.
I must always think about how it would have been if this has been around 500-800 years ago, and 25 of these were shooting at high value targets in the army across the field.
They would all miss.
First you have to invent the rubber band...
Great work!
Now that you have proven the concept, the crank effort at the end is another design optimization for scaled production.
In industry we always design to 50% engine capacity so that if we have to step outside job parameters we don’t break the system.
Time for a mini Lego version with motors
How is this your only video? It feels like a well established channel that has tons of uploads and really good videos
I achieved mach2 with nothing but a car inner tube back in 1988. Cut the whole thing into a 1 inch wide strip, tied one end to a power pole and walked the other end about 400m up the road.
It was shocking. Less than half a second to get well past the pole. It touched a parked cars wing mirror about 50m past the pole, which exploded into tiny fragments of glass and metal.
A hard grade of nylon monofilament works better than rubber as a tension spring. More energy storage per mass, and less hysteresis.
Well, it is my first time editing a video. Had I had the faintest idea of its eventual spread, I probably would've put in a bit more effort.
Destin from SmarterEveryDay might be interested in a colab, have you seen his supersonic baseball canon?
I’d wear some safety glasses
Amazing process to get to an amazing result. I work with computers for a living and it's rewarding in many ways, but not in the visceral 'I could easily land on the 'List of Inventors Killed by Their Own Inventions' page on wikipedia' kind of way. Quick technical question, the release point looked reasonably consistent across all of the force regimes you demonstrated in the video, is it a property of the geometry? Also did you come up with the release mechanism? I thought it was incredibly clever.
Yes! Sort of. Scaling up the puller force by a constant factor does not change the geometry of the throw... in a frictionless vacuum. Gravity doesn't scale, so its contribution becomes less important at higher speed. Air resistance scales properly over a wide range of subsonic speeds, but there's a discontinuity in the trans-sonic regime. The gravity effects are too small to be important here, but the release finger angle must be adjusted slightly when moving between subsonic and supersonic flow regimes.
I didn't come up with the concept of the release mechanism, it's one of the standard ways mechanical releases are built. I did come up with this specific implementation. It was designed for a much larger machine, and has a safe holding force of 15kN (FoS=5), which is enormous overkill here.
@@davideade8692 Whoa, lots of factors! Thanks for the additional info, really enjoyed this one!
@@jcims Sorry, there's an important omission in the previous comment. There are two important mechanisms that alter the drag coefficient (and thus ruin scaling). The first is trans-sonic flow, as I mentioned. The second is the onset of turbulence, which for a smooth sphere like we have here causes a sudden drop in drag coefficient around Re = 3*10^5. Coincidentally, because this sphere is fairly small (relative to the dynamic viscosity of air), the drop in drag coefficient doesn't happen before the onset of trans-sonic flow. This effect would be important with a larger sphere.
Range?
Edit: gUn cONtRoL 😢😭!!!
Three weeks. Dang! It takes me twice that long to build an AR-15 to sell to the Mexican cartel. Ha Ha, I didn't write which cartel so the Feds don't know whether to prosecute me or give me a grant and small business loan.
Reminds me of the old "Fibonacci 540" chunker design (540 for the range of motion in the throw). I think they found it too unpredictable an later returned to a sub-180 degree arm stroke. Very nice job on the engineering!
Longer strokes do hurt repeatability, and this is made worse by the proportionally high drag and compliance in punkin chunkin machines. But this machine would have about 8MJ throw energy if scaled to punkin chunker size, so drag doesn't matter very much here.
@@davideade8692 "8MJ throw energy" You know there's artillery cannons with lower muzzle energy than that...
341 foot pounds of energy carried by that 3/8 steel ball. I’d love to see some terminal ballistics of that projectile…
If he is using a 3/8 in steel ball - tha's around 3.5 g, at the speed of 450 m/s it has about 350 Joules at launch, for comparison, average 9mm bullet muzzle energy is around 500 J
So, it has some sting.
@@Gaius_Cassius - Damn. Gunpowder wins again. Back to the shop.
I don't think it would be useful for hunting pheasants but hey it is a pretty AWESOME work of engineering. Great work! :) You have GOT to get some high speed footage!
The design optimization study is great to see and the musings on the creakines of wood just wonderful, thank you for this magnificent video and design, it is inspiring to say the least.
Hey, any pointers where can I read up on thinking behind these dimensionless groups, building the unknown function, the scaling tricks? I'd like to learn about these "modern engineering concepts" that my university never told me about.
Hmm... well, I learned about the Pi theorem in a 2nd year fluid dynamics course, the scaling tricks probably came from a first year physics course. The rest is just putting them together, and the only modern part is using a computer to run the experiments. Get strong with the fundamentals. When they become an integral part of your mental toolkit, you'll be able to start combining them like this.
I think this would be a "catapult" by WCPCA rules. Trebuchets are gravity/weight powered just by definition. That's just semantics though, still an awesome catapult!
Yeah the WCPCA would call it an Unlimited Catapult, I believe. Mine is a Traction Treb. This one could be as well, even though they are still unlimited catapults in the wcpca.
Well done David! Hope you are working in a capacity that allows you utilized your talents. Reminds me of when I was a young engineer contemplating a supersonic RC airplane. Didn’t have the technology to pull that off at home, but did get to work on a Mach 10 hypersonic vehicle at work.
How did you get the rubber for this, that’s my biggest obstacle right now, started developing my own one of these for a larger projectile, but I must be a decent engineer, because I arrived at a very similar arm geometry to yours, it’s convenient as I can just look at how you did the frame, but I can’t for the life of me figure out how to get enough elastic for the force I need.
My aim is to throw around 60g at 130m/s
Very well done! Should the need ever arrive, it's possible to replace the rubber bands with an electric motor with a gearbox and a variable cam to maintain a strong and steady yet accelerating pull on the arm.
Throwing motion here happens in around 30ms, puts in 500J... 17kW. You know, that would be interesting to look into. Thanks!
That's insane. I would expect a mechanical device to barely break the sound barrier, not going nearly 100m/s over the speed of sound. Your work is truly impressive.
The next question is how hard is hypersonic
Uh... purely mechanical whips have been breaking the sound barrier for at least centuries. Possibly millennia? I wouldn't be surprised if you could attach a small ball bearing to the end of a bullwhip and have it break free at supersonic speeds. Kinda simplify this whole thing.
@@htomerif😂 it’s a bit more complicated than that
@@ludovicoch3997 oh, why don't you tell me how its "more complicated than that"?
*THIS is very cute.*
The video is amateurish, but the lad is adorable, he is doing a good job. But WHERE his protective gear, when he is working with high tensions? A failure could have easily maimed or killed the lad.