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Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

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Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#31

Post by hinkley »

thot_experiment wrote: post #23
hinkley wrote: post #12

Earlier quoted context omitted.

You'll shoot your eye out, kid.

It's absurdist to be concerned about this and be okay driving a car from a total harm to society perspective.

Heartily disagree. It's the Frankenstein problem.

As an engineer, if you can't even start a process with sobriety, rigor, and safety in mind, that cavalier attitude only amplifies as you go down the road from experimentation to design to unleashing your ideas onto the public.

It's a harbinger of what is to come if you're being a suicidal idiot during the prototyping phase. If you don't even have respect for your own safety...

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#32

Post by glitchc »

hinkley wrote: post #4

How do you responsibly test something like this? The payload isn't going to follow a ballistic trajectory, it's going to follow an aerodynamic one. You'd probably have to design something special to load into it to aim the damned thing. Which is a road trip to some place very empty in something like a 180º arc. Maybe 225º.

One possibility is to mount the trebuchet on a tiltable platform and tilt it to a suitable elevation, say 45 degrees.

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#33

Post by red_admiral »

bookofjoe wrote: post #18
genewitch wrote: post #13

Earlier quoted context omitted.

the "shot you've been waiting for" was sort of anticlimactic, but the two plywood arm shots after show what it actually sounds like. I think the grass and tree dulled the sound a lot on the metal arm. I actually have a camera that can shoot that at high speed (1200fps), but i'm sure other people have better cameras these days, mine has very low resolution.

Scientific research systems like the SCARF achieve 156.3 trillion fps but at greatly reduced spatial resolutions.

Is that the "nuclear potato cannon" one?

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#34

Post by jijijijij »

MomsAVoxell wrote: post #2

Seems like such an advance in this ancient technology. It would be really cool to see it applied in interesting ways. I really wonder just how effective this could be as a defense system .. the mind wanders with every update Tom makes .. I imagine an aiming/targetting system would make this an effective, easily replenished, low-resource weapon system for some applications. Attacking feral animals, perhaps? How could…

I think the only real advantage of this, compared to gas driven projectiles, is the lack of need for gas sealing and explosion resistance of the projectile. The projectile is accelerated much more gently. You can launch combustible, rather fragile and irregularly shaped projectiles. That said, I don't think there is much need for supersonic exit velocities for most scenarios. Maybe you could use it for impact testing without introducing a gas blast or the need of a gas sealing delivery vehicle. But I don't think you would opt for a gravity powered, purely mechanical device then.

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#35

Post by gcanyon »

gattr wrote: post #9
MomsAVoxell wrote: post #2

Seems like such an advance in this ancient technology. It would be really cool to see it applied in interesting ways. I really wonder just how effective this could be as a defense system .. the mind wanders with every update Tom makes .. I imagine an aiming/targetting system would make this an effective, easily replenished, low-resource weapon system for some applications. Attacking feral animals, perhaps? How could…

I also loved the video. But I'd think if one wanted to deploy "simple" mechanical projectile weapons at scale, pneumatic launchers would be easier, more compact and more reliable (way less cool-looking and operating, though!).

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.

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#37

Post by red_admiral »

MomsAVoxell wrote: post #2

Seems like such an advance in this ancient technology. It would be really cool to see it applied in interesting ways. I really wonder just how effective this could be as a defense system .. the mind wanders with every update Tom makes .. I imagine an aiming/targetting system would make this an effective, easily replenished, low-resource weapon system for some applications. Attacking feral animals, perhaps? How could…

> deal with avalanche conditions

Swiss solution: chuck some explosives out of a helicopter https://www.youtube.com/watch?v=H519qhLnRtM (start at 1:20)

(In the image at https://swisshelicopter.ch/de/aktuelles/721-lawinensprengen-... the explosive pack says "do not eat". I'm not reassured that we need this warning for people allowed to handle that.

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#38

Post by jijijijij »

daemonologist wrote: post #3

Also (mentioned by Tom), this elastic-powered supersonic trebuchet is an excellent video: https://www.youtube.com/watch?v=gdXOS-B0Bus

That device is so much more scary! Both really demonstrate the ridiculous amount of energy stored in a pinch of gun powder. And I presume gun powder is quite inefficient at driving the projectile, too.

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#39

Post by drcongo »

emptybits wrote: post #20

His trebuchet launched a 4 gram projectile at 776 miles per hour. That's obviously extremely lightweight for trebuchet payload, but for comparison, his projectile is approximately 62 grains so approximately twice as heavy as 30 grain high speed 22LR rounds. And approximately 1.5 times as heavy as 40 grain subsonic rounds.

What does grains mean in this context?

Re: Tom Stanton's supersonic trebuchet breaks sound barrier with gravity alone

#40

Post by bjackman »

drcongo wrote: post #39
emptybits wrote: post #20

His trebuchet launched a 4 gram projectile at 776 miles per hour. That's obviously extremely lightweight for trebuchet payload, but for comparison, his projectile is approximately 62 grains so approximately twice as heavy as 30 grain high speed 22LR rounds. And approximately 1.5 times as heavy as 40 grain subsonic rounds.

What does grains mean in this context?

It's a unit of mass used in the firearms world
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