What does grains mean in this context?

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.

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.

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.

> without requiring fire-arms training.

You'd need trebuchet training instead, which is probably not better in the long run. I bet there's still lots of ways to kill/mangle yourself with one of these, especially once you've been around them long enough to get casual and sloppy.

> 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.

Or we can just accept it as a cool gimmick, we don't have to kill animals with supersonic trebuchets really

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 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.

Drone defense? :-)

All of these things are thoroughly solved problems with embarrassing levels of cost effectiveness, far from interesting.

Please keep your thinly veiled murder fantasies to yourself

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.

He has fairly specific mechanically timed release control over it — within 0.5 degrees.

But he also used an extremely lightweight ball projectile — a few grams of 3D printed plastic — because he was only interested in the launch speed. And he pointed it in a direction where there were no people for miles.

He explains that the field he is shooting towards is over 5km of empty field. He also started his tests with much lower weight and speed to ensure proper behavior before getting up to full speed.

It's shooting 3d printed balls, I imagine they don't stay supersonic for very long. Significantly less dangerous to others than driving a car.

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

Not only is it a funny name it also appears in my subscriptions list alphabetically right below the main channel.