--- title: Tom Stanton's supersonic trebuchet breaks sound barrier... description: YouTuber and engineer Tom Stanton achieved a world first by building a gravity-powered trebuchet that broke the sound barrier. Using a 40 kg counterweight, a... canonical: https://daily.dev/posts/tom-stanton-s-supersonic-trebuchet-breaks-sound-barrier-with-gravity-alone-z3lyhhq3b twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone | daily.dev og:description: YouTuber and engineer Tom Stanton achieved a world first by building a gravity-powered trebuchet that broke the sound barrier. Using a 40 kg counterweight, a... og:url: https://daily.dev/posts/tom-stanton-s-supersonic-trebuchet-breaks-sound-barrier-with-gravity-alone-z3lyhhq3b og:image: https://api.daily.dev/og/posts/z3lYHhq3B.png og:image:alt: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone **[Hacker News](https://daily.dev/sources/hn)** · 4 min read · 0 upvotes · 0 comments ## Summary YouTuber and engineer Tom Stanton achieved a world first by building a gravity-powered trebuchet that broke the sound barrier. Using a 40 kg counterweight, a 3:1 pulley system, a 116-gram carbon-fiber arm machined on a homemade CNC mill, and a 4-gram projectile, the machine reached 2,342 RPM and launched the projectile at 776 mph — 9 mph past the speed of sound — confirmed by an audible sonic boom. Key engineering challenges included optimizing the variable-diameter drum for speed multiplication, designing a stress-resistant arm, and perfecting a millisecond-precision mechanical release mechanism. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How fast did Tom Stanton's supersonic trebuchet launch its projectile and how was it achieved? Tom Stanton's trebuchet launched a 4-gram projectile at 776 mph (346.4 m/s), confirmed by a sonic boom. It used a 40 kg counterweight, a 3:1 variable-diameter pulley drum to multiply rotational speed, a 116-gram carbon-fiber arm spinning at 2,342 RPM, and a spring-loaded mechanical release with a window of only a few milliseconds. _Engineers pushing mechanical limits track builds like this on daily.dev alongside the latest in hardware and maker engineering._ ## Community take How the wider developer community reacted, aggregated from 1 discussion and 41 comments across hackernews (as of 2026-08-09). **TL;DR:** Commenters are broadly enthusiastic about Tom Stanton's engineering achievement, praising the clever mechanical design (especially the variable-diameter drum) while debating practical applications and safety considerations — most agree it's a cool feat even if it has no obvious real-world use. **Sentiment:** 72% positive · 20% mixed · 8% skeptical **The case for** - The variable-diameter winding drum is a genuinely clever mechanism for optimizing torque delivery throughout the weight drop. - The system achieved over 40% energy efficiency, which commenters found impressive compared to alternatives like pneumatic launchers. - Safety was handled responsibly: lightweight biodegradable projectiles, incremental testing, and shooting into a 5+ km empty field. - The project is seen as genuinely educational and inspiring, motivating others to build and experiment. **The pushback** - Commenters note it has little practical application as a complete system — it was built to hit an arbitrary goal under arbitrary constraints. - Pneumatic or gas-driven launchers are seen as more compact, reliable, and cost-effective for any real deployment scenario. - One commenter dismissed the achievement as disproportionate effort for a pointless result, comparing it unfavorably to stunt content. **By community** - hackernews (positive): Broadly enthusiastic about the engineering ingenuity, with lively side threads on safety, practical applications, and comparisons to firearms and pneumatic systems, but little genuine skepticism about the core achievement. **Hottest debate:** Whether the trebuchet has any meaningful practical advantage over pneumatic or gas-driven projectile systems, or is purely a cool engineering stunt. **Open questions** - Could the multi-revolution arm and sling-release design be scaled up reliably using traditional construction materials to launch much heavier payloads? - How does the energy efficiency of this gravity-powered system compare to pneumatic launchers when accounting for the full pump-and-discharge cycle? - What would a viable auto-loading mechanism look like for a system like this? **Highlights** > I don’t think this has much practical application as an entire system. Nor is it supposed to. It was built just to achieve and artificial goal with arbitrary constraints. That doesn’t make it any less cool or interesting, but that doesn’t make it useful. Some of the features he used are pretty cool though, like varying the winding drum diameter to vary the delivered torque over the course of the weight drop. > — [nkrisc on hackernews](https://news.ycombinator.com/item?id=49233601) > Very early in the video, he explains that while previous builds used steel ball-bearings, that's not responsible at these energy levels, so he switches to lightweight balls made of biodegradable plastic. There's comparatively little energy in the projectile after release, and it's only supersonic for a few feet. Further, you test in an enormous empty field, as he's doing. > — [myself248 on hackernews](https://news.ycombinator.com/item?id=49233377) > I think the cycle time on this would be far superior to a pneumatic system: cycling this system effectively means lifting ~100 pounds ~8 feet, which a reasonably fit person (who could reach that high) could do several times a minute for extended periods. He got an efficiency over 40% (if memory serves, I watched this video yesterday) -- I wonder between pumping and discharge how efficient a pneumatic system would be, but I can't imagine that it's higher. > — [gcanyon on hackernews](https://news.ycombinator.com/item?id=49234159) > What's extraordinary about this? You can get any amount of energy from gravity and transferring it to a small object doesn't sound like an especially complex feat. It's one of those influencer videos in which someone devotes a disproportionate amount of effort to accomplish something pointless- Mr. Beast does the exact same without any pretense of showing something useful. > — [throw310822 on hackernews · 2 comments](https://news.ycombinator.com/item?id=49234693) > What a sad and pathetic opinion, especially when targeted towards such an incredible contributor as Tom Stanton, a true educator and an energetic and excited engineering mind. > — [WheatMillington on hackernews](https://news.ycombinator.com/item?id=49234811) **Source threads** - [hackernews](https://news.ycombinator.com/item?id=49232110) · 129 points · 41 comments ## Similar posts on daily.dev - [Creating A Supersonic Trebuchet](https://daily.dev/posts/creating-a-supersonic-trebuchet-gui209trr) · Hackaday · 1 upvotes · 0 comments - [Whip-Cracking Machine Reliably Breaks The Sound Barrier](https://daily.dev/posts/whip-cracking-machine-reliably-breaks-the-sound-barrier-avfoc9evl) · Hackaday · 0 upvotes · 0 comments - [Forget rockets — Longshot wants to fire cargo into space from a gun. See it at TechCrunch Disrupt 2026](https://daily.dev/posts/forget-rockets-longshot-wants-to-fire-cargo-into-space-from-a-gun-see-it-at-techcrunch-disrupt-20-8mzjafq81) · TechCrunch · 0 upvotes · 0 comments - [These tiny drones are powered by sound](https://daily.dev/posts/these-tiny-drones-are-powered-by-sound-rqya8ok3t) · Robohub · 0 upvotes · 0 comments --- Tags: [#physics](https://daily.dev/tags/physics), [#mechanical-engineering](https://daily.dev/tags/mechanical-engineering) [View this post on daily.dev](https://daily.dev/posts/tom-stanton-s-supersonic-trebuchet-breaks-sound-barrier-with-gravity-alone-z3lyhhq3b) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone","url":"https://daily.dev/posts/tom-stanton-s-supersonic-trebuchet-breaks-sound-barrier-with-gravity-alone-z3lyhhq3b","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/tom-stanton-s-supersonic-trebuchet-breaks-sound-barrier-with-gravity-alone-z3lyhhq3b"},"datePublished":"2026-08-09T16:47:57.485Z","dateModified":"2026-08-09T19:49:21.664Z","description":"YouTuber and engineer Tom Stanton achieved a world first by building a gravity-powered trebuchet that broke the sound barrier. 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