13 ms·
Supersonic Trebuchet [video]
- arlattimore 2mo agoTom Stanton has a raft of cool videos, I like the engineering iterations he often goes through to find a working prototype.
- kreelman 2mo agoAgree! He has some great videos. I watched this one and was impressed at the calculations, the transparency and the celebration at the end when he reached supersonic speeds.
- Mashimo 2mo agohttps://news.ycombinator.com/item?id=49232110 https://news.ycombinator.com/item?id=49232110
- grahar64 2mo agoAt least this is a direct link to the video and not blog spam
- pino83 2mo agoOr, in other words: There was some text to read and some pictures to look at. For topics in the range of "supersonic trebuchets", I'm absolutely okay with quickly reading some lines of text; dynamically deciding how quickly/thoroughly I read, what paragraphs to skip, etc. What I'll definitely NOT do: Watch a video clip about it.
- grahar64 2mo agoSo you won't support the creator, but support a person who summarizes the creator. You could have just pasted the link into Claude and asked for a summary of the blog post.
- pino83 2mo agoMaybe that's even the same guy?! But I don't know... A thing that I completely don't care about: Supporting some YouTube guys. YouTube "creators", even if they are not basically "influencers" (a.k.a. advertizing), even in the best case, a YouTube guy is for me the same as someone at RTL, DMAX, Fox, or any other random TV station. It might even be that I watch their show every now and then... But I'm not constantly thinking about how I can support these guys. And IF they actually disappear tomorrow, there will be other ones coming up. There is DEFINITELY no scarcity in YouTube guys... PS: The narration inside the community is fundamentally more romantic. But guess what, I don't care. ;) PPS: With all my browser addons (incl. "Sponsor Block" - every YouTube consumer should have it!!!), I'd not be so much of a support anyways. PPPS: The first thing when someone would ask me to consume a YouTube clip would be to ask Claude or whatever service to generate a summary/transcript for me. I reject to constantly burn multiple minutes in order to consume random/funny/pointless content that could be a matter of 10 seconds if provided as text together with four of five images.
- Hugsbox 2mo agoI'd much rather read a blog post about it than watch a video. Maybe that's just my preference, but it's a better format for me.
- londons_explore 2mo agoI suspect that with a little iterative modelling of the whole system with derivatives, efficiency could be bought from ~40% to ~80%, giving you an extra few hundred mph...
- repeekad 2mo agoI wonder if Claude has guardrails against hyper optimizing a trebuchet projectile into a proper bullet
- ezst 2mo agoHow would you even get Claude involved in that? This isn't your git repo that a language model can scrape for textual content.
- bonoboTP 2mo agoIt could make simulations and read the CNC templates and the files for the 3D printed parts.
- ezst 2mo agoAnd then do what? Do you have any evidence that Claud would do anything relevant with those?
- bonoboTP 2mo agoIt could come up with design adjustments and measure their impact in the simulation. But the sim2real gap may be too large.
- ezst 2mo agothere might be several gaps before that, even. From the top of my head: - text description to 3D geometry gap: you can't easily describe complex geometry in a language that's common and convenient to both humans and machines - 3D geometry to physical model gap: material , geometrical constraints induced by manufacturing (machines, tools, costs, …) - physical model to model fit for simulation gap: meshing, constraints, stress modelling, … - simulation outcome to fitness assessment gap: now you have a high-dimensional and numerically heavy simulation to weigh against a non-rigorously defined acceptance criteria - simulation outcome to geometry profiling gap: how do you even start to guide the LLM into the vast space of possible changes to apply to the 3D geometry and reboot that loop? LLMs don't strike me as a particularly relevant technique to apply here, to be honest.
- londons_explore 2mo agoInteresting that his spool goes bigger at the end...? I would think you want it decreasing to near zero to extract all the kinetic energy from the mass, leaving the mass stationary as it hits the ground.
- vanderZwan 2mo agoI think the idea is that at the end the sling starts to unwind too, increasing the effective arm-length (that non-linearity is one of the reasons trebuchets are so efficient to begin with). As a result it's possible that decreasing the spool to near zero is like putting the gears of your car too high. Reducing the spool size ensures there's enough torque left to put more power into the final swing.
- vanderZwan 2mo ago(too late to edit my comment, but I obviously meant increasing the spool size near the end, not reducing)
- drtoboggan 2mo agoReally wondering up to what point I can build a trebuchet in my backyard before the authorities start to complain
- rwmj 2mo agoSurely that depends on the side of your back yard?
- aa-jv 2mo agoMaybe it depends more on the vicinity to others' back yards... ?
- xdertz 2mo agoThere are three issues that arise - structural: There are height and size limits on things you can build without a permit - trespassing: flinging objects onto others people property is illegal - endangerment: any activity that can endanger other people is illegal All of these three depend on how rural you live I guess. So in a suburban neighborhood I would assume they get involved very quickly.
- Tangurena2 2mo agoI suggest having a BBQ with your neighbors. That should minimize the pre-launch problems. If you use a steel ball bearing like he originally thought, that bullet will be the start of your legal problems.
- DiffTheEnder 2mo agoThe key is to live in a place where the authorities are willing to look the other way for some other rewards.
- foo42 2mo agoGreat video. Other trebuchet fans who dream of building one some day may be interested in googling "walking trebuchet" for a surprisingly high complexity/results ratio.
- kitd 2mo agoLove it! But shouldn't that be "high results/complexity ratio"?
- fragmede 2mo agoDepends on if the journey and not the destination is what's important to you. ;)
- aa-jv 2mo agoEvery time I see a strandbeest[1] on the beach somewhere, I wonder to myself why it hasn't got an array of trebuchet included, also recharged by the wind, to pick up sand balls and throw at people. Just for the fun of it. Pure whimsy. [1] - https://www.strandbeest.com/ https://www.strandbeest.com/
- MomsAVoxell 2mo agoI would love for this to be optimized to the point that its portable and can be carried around, assembled on the side of the mountain, and used as a low-cost, efficient way to throw things from one mountain to another, maybe for avalanche control, or cloud seeding, or indeed for seed bombs intended for re-wilding hard to access places, or something. It just seems like such an obvious tool, rather than a weapon.
- roer 2mo agoYou'd probably be better off using a rail gun if you want a carriable launcher
- MomsAVoxell 2mo agoReally? With the required infrastructure to charge it, also in the backpack, for a few weeks of work too? Is gravity a subscription service in your world?
- roer 2mo agoDepends entirely on the specifics of your usecase what concessions you want to make. One launch location or multiple? What frequency of launch? How heavy are the payloads? How good accuracy? What transport methods are available? How long should it operate without maintenance? Is solar an option if we go electric? Etc.
- MomsAVoxell 2mo agoMultiple locations, thus the need for it to be easily portable. I guess a couple hundred launches a day would be useful for seed-bombing/re-wilding, especially on rugged terrain. Seed-bomb weight: I’d say anywhere from 1-10 grams, maybe? Accuracy - it’s a seed bomb, you want dispersal to happen, so maybe the more interesting question is, how would you design a seed bomb to survive the trebuchet speeds and g-forces while also allowing for directed dispersal in the intended area. Seed-bomb design for impact conditions is also something of interest - some seeds need to be embedded in a layer of soil, some don’t. There are many parameters to optimize in the seed-bomb side of things, too. Transport method: backpack-friendly, I think. I’d hike to an area, set up the trebuchet, and spend the day dispersing in a wide circle around the base. If the terrain is rugged, portability is especially important. Operational time - one thing I think is important is that the trebuchet be resilient for long term use. If Toms’ engineering efforts prove fruitful, I’m sure the material construction will get some optimization such that, perhaps, the only thing that would need to be maintained would be the line - however, this is a known science, see for example the sailing industry, rappel lines, etc. Solar/electric? I think a wind attachment for rewinding might be a bit more productive. The scenario: a team of 5 is off for a month in rugged terrain, with the intent of dispersing targeted seed packages over a wide region. The seed bombs are designed to protect the seeds, the trebuchet is designed to deposit them sufficiently well that they remain viable in their final destination. We hike out there for a couple weeks, do a mass trebuchet dispersal, we come back a year later and observe the results.
- manlymuppet 2mo agoFuckin love this guy
- mywacaday 2mo agoIf you like Tom you will probably also enjoy https://youtube.com/@stuffmadehere https://youtube.com/@stuffmadehere
- manlymuppet 2mo agoI am familiar, and I love that guy too!
- manlymuppet 2mo agoAnother guy to love: https://youtube.com/@SteveMould https://youtube.com/@SteveMould
- vintermann 2mo agoI, too, enjoy competence porn YouTube. But seriously, it's one of those things we had preciously little of before online video became a thing.
- matthewpick 2mo agoYou’ll also enjoy superfastmatt - he mostly does car projects.
- roomey 2mo agoThinking this approach out, could someone correct me if I have this wrong. So he gradually increases the energy transfer from the weight to the arm over the course of the drop. But that arm swinging around must have a lot of energy loss due to friction and air resistance. This loss will rise exponentially with the speed increase right? So in a sense he is holding his energy budget in a very inefficient phase, with high losses. Two things support this. A) he spent a lot of time trying to make the arm more arodynamic. B) The spool widening at the end, which is essentially changing back down gears, applying more torque, right at the end when you want speed. An alternative would be to drop the weight, and let it fall unrestricted until it gets to it's highest speed (this would minimise friction and air resistance) and only at the end of its fall, transfer the energy into the arm. In this case the arm would only need to rotate 180 degrees or whatever, and not waste energy rotating right? And then, to take this a step further to make this work there would need to be some flexibility or elasticity in the system to take energy from the high speed falling weight to the arm. And what you have ended up with is something that looks like.... A whip!
- fooqux 2mo agoIf I'm picturing what you're explaining correctly, I think this would be difficult. Suddenly accelerating the arm from zero to hundreds of mph would put immense stress on the arm, not to mention whatever you're planning on using to transfer that energy (you kinda hand waved that bit). I think your assessment is correct about the energy losses. I'm just not sure about the fix.
- roomey 2mo agoI think the fix is essentially a whip, that's what I meant by elasticity and flexibility. If you want to accelerate a weight quickly in a single swipe, (simplified) gradually reducing the mass along the length of the whip imparts more kenetic energy at the end (the whip crack). So the arm would no longer be rigid, although you can see in the OPs video it isn't actually fully rigid.
- lovlar 2mo ago
- arielpetit 2mo agoInteresting
- cubefox 2mo ago107 more comments here: https://news.ycombinator.com/item?id=49232110 https://news.ycombinator.com/item?id=49232110
- chakintosh 2mo agoSpinLaunch: https://www.thebrighterside.news/post/spinlaunch-looks-to-slingshot-satellites-into-space/ https://www.thebrighterside.news/post/spinlaunch-looks-to-sl...
- oflannabhra 2mo agoTom is an amazing engineer. His journey in incrementally engineering a plane powered by compressed air has been awesome, both to see the iteration, but also to see his skills grow.
- Ancalagon 2mo agoagreed I love following this guys stuff!
- user205738 2mo agohttps://youtu.be/gdXOS-B0Bus https://youtu.be/gdXOS-B0Bus