47 ms·
Supersonic Trebuchet
- deleted 5y ago[deleted]
- EamonnMR 5y agoHaving to stand downrange of it to windlass it is intimidating.
- jacquesm 5y agoReal Men (tm) stand in the plane of rotation.
- throwaway81523 5y agoCute. It is around 8 feet long and per the comments, it throws tennis balls. Throwing a tennis ball at supersonic speed is nothing to sneeze at, but the really impressive thing about historical and modern trebuchets is how big some of them got. They could throw things like pianos, as in a famous Northern Exposure episode. Doing that supersonically would have really been something ;).
- mlindner 5y ago> per the comments Why are you believing comments over what the content of a video/article is? And you're wrong.
- throwaway81523 5y agoThe article didn't say either way. The comments gave info that I didn't particularly have reason to disbelieve. I didn't have any interest in watching the video once I found the info I wanted. The article could have just said "it throws ball bearings" but it didn't, making it useless.
- InitialLastName 5y agoThe comment you're referring to is about the trebuchet that the commenter built (not the subject of the article). The article itself is blogspam that adds effectively zero content to the video other than to capture some advertising traffic.
- tantalor 5y agoNo, it throws ball bearings.
- pacificmint 5y ago> They could throw things like pianos One example: Trebuchet throws a piano that has been set on fire at Burning Man: https://www.youtube.com/watch?v=SgboQNcRN5w https://www.youtube.com/watch?v=SgboQNcRN5w
- speedgoose 5y agoSuch a dense crowd doesn't seem to be the best environment to throw a burning piano with a trebuchet, but I guess I don't get the point of the burning man.
- Robotbeat 5y agoLiterally just watch the video.
- wscott 5y agoYes he ends up with a cute toy that flings a marble but sounds like a rifle. But in the video he explains the engineering process to start with the desired goal and then optimized and derive the parameters he needed to achieve that result. It was a good example of engineering.
- bee_rider 5y agoInteresting how different his device is, from historical trebuchets. In particular, they seem to maximize arm length, while he seemed to go for the shortest arm he could. I wonder if it is entirely the materials difference, or if his optimization was also much better than theirs. It would be cool to see his design built in period materials.
- Robotbeat 5y agoHe built his arm first out of plywood and I’m pretty sure you could easily build the same design out of a high quality single piece of wood. It really comes down to an extremely well-optimized design.
- ggcdn 5y agoRight, but I think its the high quality elastic bands that would be difficult to replace.
- Robotbeat 5y agoThey could be replaced with either a weight, steel springs, or perhaps rope or sinew cords like the Romans used. Rubber is more effective and compact, but watch the video and you see there’s nothing particularly special about using rubber & he could’ve picked something else. The rubber puller itself does not exceed 10 m/s.
- creato 5y agoI agree he could have used some other spring, but I don't think he could have used a weight. The acceleration of springs/rubber is potentially much greater than a weight (at least one starting at rest).
- deleted 5y ago[deleted]
- mootzville 5y agoThat's pretty awesome. May have to give a whirl. Thanks! I remember years ago seeing some show about weapons seized in jail, and one of them was a crossbow made out of underwear that could shoot a plastic fork through a steel filing cabinet.
- nuccy 5y agoFun fact, you can accelerate an almost-everyday object to supersonic speeds: whip tip [1,2]. 1. https://en.wikipedia.org/wiki/Whipcracking https://en.wikipedia.org/wiki/Whipcracking 2. https://www.youtube.com/watch?v=AnaASTBn_K4 https://www.youtube.com/watch?v=AnaASTBn_K4 (very much recommended)
- system2 5y agoAnyone interested, amazon sells Bullwhips for $23. Almost got one.
- injidup 5y agoI have one at home. They are awesome fun. But you only get a few cracks off before people start poking their heads out of windows. They are easily as loud as a small firearm.
- fho 5y agoFunny thing: a friend of mine lives in rural Bavaria, with a very old, conservative land-lady. The kind that will call you once you exceed your lawful one hour of instrument practice time per day. Still, she allowed rehearsals in the backyard from what can only be called a music formation comprising accordion ... and bull-whips. Like literally whipping to the beat of the music, hours of staccato whip cracking. I honestly had no idea that that existed. Example: https://www.youtube.com/watch?v=QquXdrDcX7I https://www.youtube.com/watch?v=QquXdrDcX7I
- twic 5y agoAt 5:30 in the video he claims that the problem is infinite-dimensional. How so?
- bunje 5y agoSolutions to differential equations belong to infinite dimensional function spaces unless discretized.
- pharke 5y agoReminds me of the unlikely idea of using a whip crack to send something into orbit[0] maybe SpinLaunch needs to consider adding another joint to their arm. I'd love to see a massive trebuchet launch something into orbit. [0] https://futurism.com/the-byte/amazon-patented-system-whips-stuff-space https://futurism.com/the-byte/amazon-patented-system-whips-s...
- grayrest 5y agoThe idea of using whip cracks for acceleration features fairly prominently in Neal Stephenson's Seveneves. None of the instances in the books are sized for orbital launch but that was the first time I encountered the idea.
- jamestimmins 5y agoIn general, it was fascinating to see how much of Seveneves was devoted to acceleration and orbital mechanics.
- jessaustin 5y agoNot really a surprise, though, after Anathem.
- jamestimmins 5y agoFunny, earlier today I was thinking about how Anathem was fascinating but the least approachable book I've ever read
- jessaustin 5y agoI'll admit I was a bit confused after the first section in which they interview Flec. I read that section again, and then everything made sense. It may have helped that I have read (numerous times) Wolfe's The Shadow of the Torturer, of which the initial chapters of "mathic" life in Anathem are a sort of pastiche. Stephenson gets plenty less approachable. I have tried multiple times to read at least two of the three books in The Baroque Cycle, and every time I have failed to progress.
- chronolitus 5y agoAmazing project! Although, I would probably err on the side of caution and at least wear some safety glasses when hand-loading a supersonic trebuchet.
- orangepenguin 5y agoI had the same thought! Earplugs for the sound might not be a bad idea either.
- kolla 5y agoI think if anything in that machine snaps it would rip right through his body.
- Nomentatus 5y agoNext stop lunar surface! Something like this may be what you need to export lunar materials from the surface, say to the LaGrange point.
- leephillips 5y agoI’d like to suggest linking directly to the video (https://www.youtube.com/watch?v=gdXOS-B0Bus https://www.youtube.com/watch?v=gdXOS-B0Bus) instead of the hackaday page, which doesn’t even pretend to add anything and is largely incoherent besides.
- jacquesm 5y agoHackaday is just blogspam. They happily rip off your work.
- AceJohnny2 5y agoOn the other hand, I would never have heard of any of the cool projects they feature if not for Hackaday. Do you know of better aggregators for such content?
- thesmok 5y agoYou're not accounting for all the high quality content they produce. Like Creating a PCB in Everything, or Logic Noise. https://hackaday.com/tag/logic-noise/ https://hackaday.com/tag/logic-noise/ https://hackaday.com/tag/creating-a-pcb-in-everything/ https://hackaday.com/tag/creating-a-pcb-in-everything/
- agumonkey 5y agothey also have a kind of community website full of maniacs (in the good hacker sense) people making discrete custom CPUs for instance I admit I don't like hackaday a lot but they have some value
- dougmwne 5y agoI know not with what weapons World War III will be fought, but World War IV will be fought with the supersonic trebuchet. Excellent engineering video and it hope it inspires more young engineers than it lands in the ER. Stay safe kids!
- smudgy 5y agoI know a large group of weirdos that are probably flipping their shit with this. Not only the superior siege engine but the supersonic one too.
- JoeAltmaier 5y agoI've always thought the trebuchet cord should be wrapped around a wheel. Then the force would always be rotational - no component of fource would pull against the hub and be wasted.
- mleonhard 5y agoThe arm is just a large wheel and a small wheel on the same axle, with the unnecessary parts cut away. Round (not-cut-away) wheels will capture more of the energy as rotational inertia, leaving less for the projectile.
- JoeAltmaier 5y agoSort of. A light-weight wheel compared to the load etc is negligible. And an arm is definitely not a wheel - the rope doesn't always pull completely tangential to the rotation, not at all. Nowhere near. That's the point.
- yetihehe 5y agoYou can use that to your advantage building flywheel trebuchet: https://www.youtube.com/watch?v=RVT5i4nhIGs https://www.youtube.com/watch?v=RVT5i4nhIGs
- mgsouth 5y agoThe most striking aspect is that he was explicitly optimizing for project difficulty. I smiled when he said, in effect, 'let's mathematically calculate How Hard Can it Be'. Sure kid... But that's what he did. Fantastic job determining the criticial criteria and engineering to it. 3 weeks total project time. Kid's got a future...
- jacquesm 5y agoAt 13:12 in that video notice the tension in the frame and how the main spars are getting out of alignment with the part the winch is mounted on. I wonder how much spare strength there still is but it can't be much. Pretty scary machine!
- tempestn 5y agoYep, that was pretty terrifying to watch.
- jacquesm 5y agoIndeed, I wasn't comfortable watching it until I realized that he was the one that posted the video. But instant desintegration was definitely on the menu there and once stuff comes apart and starts flying it's impossible to predict trajectories. That's a very large amount of energy on what looks to be two run-of-the-mill boards, they're fortunately under compression but the joint at the bottom looks (far) less than ideal for this, especially with the holes drilled in line with each other (that's a definite 'no' if you want to avoid splitting the beams). A++ for the theory, but the implementation is not something I'd want to be near when it is in operation, it is just too unsafe judging by my somewhat experienced DIY eye.
- deleted 5y ago[deleted]
- naikrovek 5y agoI'm sure the guy is aware of how much stress he's putting the wood under, and about how much it can withstand. when I was a kid, my dad made an engine hoist frame out of wood. that thing creaked out some scary sounds when he lifted whole diesel trucks with it when load testing, and it didn't even faze the hoist frame at all. it sounded like it was going to explode into a billion supersonic toothpicks and didn't even visibly move. we painted red lines across joints to see stress movement more easily and nothing ever moved. his material of choice? 4x4 construction lumber. it is amazing what wood can withstand when you understand what you're asking it to do, and design so that material properties are fully exploited. my point: loud creaking is not necessarily indicative of impending failure.
- thomasfromcdnjs 5y agoHow far does the projectile go?
- cwkoss 5y agoI'd be very impressed if they were able to find any of the projectiles after firing
- dredmorbius 5y agoWait for snow. Smear bearings with orange grease. Look for the orange smear. (A drone would help here.) A friend's father used to build and test rockets using this principle, though he'd smear the outside of the rocket casing. During the Cold War. Up north. That earned the family a visit from an air force colonel one day, apparently after pilots had put together the sighting of high contrails, orange snow smears, and the lone figure seen trudging toward the smear.
- cwkoss 5y agoAh, that's a good trick. I bet if he greased a dozen ballbearings in snow, could probably find at least a few. I'd imagine these projectiles are going thousands of feet, would still be tough to find them all.
- jacquesm 5y agoDepends very much on the launch angle, anywhere from a few hundred meters to well over a kilometer. You can play around with this: https://www.omnicalculator.com/physics/range-projectile-motion https://www.omnicalculator.com/physics/range-projectile-moti... Note that it does not take projectile shape (and so drag) into account and that's the largest factor.
- pjkundert 5y agoThis is a perfect illustration of why I chuckle when people claim to be able to "ban guns". He is projecting a 3/8" (.375 caliber) round steel projectile at ~3x the maximum velocity limit for an unrestricted air rifle in Canada. Using a crank and some hefty rubber bands.
- bfung 5y agoSure, but this project isn’t really hand held and mobile and reloadable in a small amount of time. It took some smart enough person to operate as well. Some nuance and differentiation still appropriate; this is as close to an air rifle as vacuum tubes are to SoC.
- pjkundert 5y ago"Sure, Mr. Wright, but the craft isn't reliable and easy to fly..."
- muglug 5y agoI'm not sure what point you're trying to make... that machine is not particularly mobile. It takes him 5 minutes to load a projectile. The UK has banned guns. People there generally don't build trebuchets to compensate. Murder rate in the US is 18x higher than in the UK, and 23x higher than in Canada. Edit: there are obviously other ways to murder someone, knives being the most common in the UK. If you're a good aim, guns are a lot less messy, and I think that makes a big difference to would-be murderers.
- jrexilius 5y agoYour statistics are wildly off: UK Homicide rate 2018: 1.20/100k US Homicide rate 2018: 4.96/100k And making something illegal is not the key factor in comparing countries: UK Drug Overdose Deaths 2020: 7.6/100k. US Drug Overdose Deaths 2020: 28.1/100k.
- penteract 5y agoYou're right. There is a difference between murder and intentional homicide, but the factor of 18 appears to be using the raw numbers of murders rather than murders per person.
- spir 5y agoI'm curious, could this be a realistic and cost-effective weapon for, for example, militias in third-world countries?
- FetusP 5y agoI can't imagine so. Even if it was somehow accurate, it wouldn't be very mobile or quick.. I'd imagine one person with a pistol could take out a good sized group of people shooting marble trebuchets
- rpmisms 5y agoThat heavily depends on range, pistols are not known for accuracy at range.
- bluGill 5y agoStill pistols have some barrel so they should be vastly more accurate at range. I forget the ranges they are good for, but I think within 100 meters you can still hit your target most of the time. Though if this is a real war I'll take a real rifle. The ar15 (m16) and ak47 are the staples of modern armies for good reason, and they have much better sniper rifles that in the right hands are amazing.
- SV_BubbleTime 5y ago> Still pistols have some barrel so they should be vastly more accurate at range. Way misguided here. Pistol accuracy has almost nothing to do with the barrel. Not in the sense that you think. Accuracy is repeatability. That means tolerances. The bore, rifling, the chamber dimension, the jump distance from the bullet to the rifling in the chamber, the natural resonances… but then just or more importantly is your ammo. You have you ogive (“oh-jive”) of the bullet, the sectional density, the tail shape, it’s ballistic coefficient (actual, not G1 or G7 artillery guesses), your powder burn rate, consistency of the powder, amount obviously, the case neck tension and length, primer hole and primer consistency… Then you get into dwell time of the action and all the user variables you can’t account for without bolting the gun to a frame. … so as to pistol accuracy, you can have the world’s most accurate pistol and barrel ever made, and still have shit long distance accuracy. A barrel isn’t going to help you. Pistol bullets are bricks compared to rifle bullets. A ballistic coefficient of .1 is just never going to be very consistent because at distance it’s dumped so much of it’s speed via air resistance that it’s supersonic time is limited and will enter transonic and subsonic quickly. This isn’t what pistol rounds are designed for. You want bricks with high sectional density for shooting things up close.
- beckerdo 5y agoIt is interesting to me how many engineers hop from English ("3 inches to go on the rubber band") to the metric system ("400 meters per second"). Andy Weir touches on this in his book "Hail Mary".
- durnygbur 5y agoStill missing the "football fields" unit of measurement.
- mlindner 5y agoExcept this person isn't American, as he lives on Manitoulin Island, which is in Canada.
- elliottkember 5y agoI am from NZ and find myself doing this. The difference is whether something is estimated or measured. If it’s a rough estimate, and the value doesn’t matter at all, I use inches. So “six inches” is more of a way of describing “about this much”. It’s deliberately imprecise.
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- worldvoyageur 5y agoHere is the local newspaper's coverage of the supersonic trebuchet (Manitoulin Island, northern Lake Huron in Canada): https://www.manitoulin.com/island-engineer-designs-supersonic-siege-engine/ https://www.manitoulin.com/island-engineer-designs-supersoni...
- cushychicken 5y agoI have two words for this dude, and they are safety glasses.
- Taniwha 5y agoI'm not sure that there exist 'safety' glasses that would actually be safer in this situation
- cushychicken 5y agoI'd be less concerned about him shooting his eye out than I would be about something unexpectedly breaking and sending debris flying.
- benlivengood 5y agoIf you build one of these then practice better range safety than this guy. He apparently has the trebuchet loaded while tensioning the rubber bands downrange of the release point. Excellent engineering work though.
- deleted 5y ago[deleted]
- lifeisstillgood 5y agoThis is a perfect example of engineering. He says it at the end - its not something that could ever be arrived at by accident. (And I suspect its not feasible to launch sizeable weights (bowling balls) at near mach 1. The Ancient Romans would have been disappointed :-)
- sillysaurusx 5y agoHmm. I'm not so sure about the bowling ball. It seems almost straightforward to scale this up as far as you want. You wouldn't be able to use wood, and the hard part would be to find a winch that won't snap, but it seems like one must exist.
- hoseja 5y agoThe limiting factor seems to be the arm, which would probably become impossible even with modern materials pretty soon as you increase weight.
- clarkmoody 5y agoThe SpinLaunch[1] folks are betting on being able to do it. [1]: https://www.spinlaunch.com/ https://www.spinlaunch.com/
- lifeisstillgood 5y agoWait what. Seriously no they cannot mean it. Surely that's just Jules Verne's big gun in Florida? Is this for real?
- yutyut 5y agoThis post prompted me to google "last time trebuchet used in combat". The answer appears to be 2013/14 by Syrian Rebels fighting against the Syrian Army. https://www.quora.com/Warfare-When-was-the-last-time-a-catapult-or-trebuchet-was-used-in-a-battle https://www.quora.com/Warfare-When-was-the-last-time-a-catap...
- alg_fun 5y agoThere was also a trebuchet appearance during Ukranian riots in 2014: https://www.youtube.com/watch?v=IEY4WG7P0NQ https://www.youtube.com/watch?v=IEY4WG7P0NQ
- CoastalCoder 5y agoI really hope he gets to partner up with Smarter Every Day or with The Slo Mo guys, for high-speed recording. I'd love to see how the trebuchet parts bend/vibrate during a prep/launch.
- deleted 5y ago[deleted]
- westcort 5y agoMissed the opportunity to use the Trebuchet MS font: https://en.m.wikipedia.org/wiki/Trebuchet_MS https://en.m.wikipedia.org/wiki/Trebuchet_MS
- DeathArrow 5y agoUS will impose a ban on rubber exports for Iran and North Korea. :D
- eCa 5y agoOff topic: What’s up with the ”[Name]” quoting style they’re using? I’ve only ever seen it when changing names/words inside quotes[1], but here it is being used outside of quotes. [1] Which I don’t mind when used within reason.
- mrguyorama 5y agoIt's just a long time habit of Hackaday. They've been doing it since I started reading in like 2008. Just be glad they decided to move beyond black and white pictures!
- boringg 5y agoBuilt at trebuchet for physics high school class eons ago. This is that same project after completing an engineering degree and dosing it with steroids. Well done. Kind of wish I had gone back to my trebuchet post engineering program.
- egberts1 5y agoInstead of torsion-applied force for his videoed trebuchet, he could have gone with a set of spiral gears to obtain the progressively increasing speed using just the original gravity-based counterweight method. Something like toroidal continuously variable transmission (CVT) in today’s automobile. https://en.m.wikipedia.org/wiki/Continuously_variable_transmission https://en.m.wikipedia.org/wiki/Continuously_variable_transm...
- CRConrad 5y agoCool, hadn't heard of this guy before. Judging from the headline, I would have assumed it was Tom Stanton, or even more probably, Jörg Sprave. (Or, dammit, what's the name of that English guy who builds and sells medieval weapons?)