[James], aka [Turbo Conquering Mega Eagle], is not your typical Hackaday poster boy. Most of his builds have a “Junkyard Wars” vibe, and he’d clearly be a good man to have around in a zombie apocalypse. Especially if the undead start driving tanks around, for which purpose his current anti-tank compound crossbow is apparently being developed.
At its present prototype phase, [James]’ weapon o’ doom looks more fearsome than it actually is. But that’s OK — we’re all about iterative development here. Using leaf springs from a Toyota Hi-Lux truck, this crossbow can store a lot of energy, which is amplified by ludicrously large aluminum cams. [James] put a lot of effort into designing a stock that can deal with these forces, ending up with a composite design of laminated wood and metal. He put a lot of care into the trigger mechanism too, and the receiver sports not only a custom pistol grip cast from aluminum from his fire extinguisher foundry, but a hand-made Picatinny rail for mounting optics. Test shots near the end of the video below give a hint at the power this fully armed and operational crossbow will eventually have. The goal is to disable a running car by penetrating the engine block, and we’re looking forward to that snuff film.
If rubber band-powered crossbows are more your speed, take you pick — fully automatic, 3D-printed, or human-launching.
Fun fact: even toy crossbows are banned in Poland thanks to our amazing ‘weapons and ammunition act’ (‘ustawa o broni i amunicji’). This thing would easily get you 10 years in jail.
Glad I don’t live in Poland! Nothing against Poland whatsoever, I just happen to be a gun enthusiast.
Funnier fact, black powder guns made before 1885 and their replicas are fully legal in Poland without any need of licensing and registration (registration is optional) but if you want to buy black powder you need an european firearm pass. Even funnier, some guy won a court case and owning a fully operational XVI century cannon is also legal in Poland :v
Think that’s bad? Here in the great nanny-state of Australia, anything that projects any sort of projectile using compressed air, no matter how slow the velocity or how low the air pressure is (even if compressed by hand), is classified as a firearm. And getting a firearms license over here isn’t exactly easy. Here is an example of a small children’s toy that fell under our firearms classification and had to have a special exception made for it: https://www.police.vic.gov.au/content.asp?a=internetBridgingPage&Media_ID=78688
And the Australian media keeps on drumming how safe Australia is without guns.
Meanwhile crims are shot dead in public parks … with guns …
No way that’s getting through an engine block. Cool build though.
Does anyone else naturally look away when someone is welding even in a video ?.
No, of course not. That would be silly.
I’ve never, ever done that too. ;- )
Probably a good reflex to have, I don’t feel foolish about it.
The guy is an idiot.. angle grinder, face up close and no eye or face protection. He will be blind soon.
How do you know he isn’t wearing fully covering protective contact lenses?
Just don’t keep the rotational plane of the cutting disc from intersecting your face and you are good, rust and sparks might still get in your eyes, but that’s just a nuisance that seldom is serious. 30 years of angle grinding without glasses and disc guard only sent me twice to the ER with stuff needing to be picked out of my eyes.
Wow, you didn’t get the hint after the first trip?
Well, safety glasses would have meant that you would have had to go to the ER… 0 times.
I ended up in the ER after grinding WHILE wearing glasses. They aren’t perfect. (Spark bounced off my cheek and managed to find the very small gap between my cheeks and the safety glasses and straight into my eye. Luckily it didn’t have enough energy at that point to penetrate and only left a small crated and a heck of a lot of irritation)
I had one get through the vent holes and into my eyes. From that point on I only used the vented cap goggles.
His response to that :
https://www.youtube.com/watch?v=JGJQNTTbMeo
Cheers Mike!
20mm cannon vs engine block:-
https://youtu.be/V8FzzEyegJQ?t=112
Cams are waaaay too beefy…weight of those cams has a very significant impact on crossbow performance, you want them as light as possible…
The mechanics of this are either too complex (slowing down acceleration of the bolt to increase accuracy?) or they’re not – it would be interesting to compare power against a simple leaf-spring setup.
Very cool! Still needs work, but that doesn’t kill the cool factor.
Almost makes me wish for a zombie apocalypse just to see what this guy comes up with. Also, youtube’s curated selection of followup videos is hilarious. I never knew there was so much slingshot porn out there.
You may want to check out Jorg Sprave’s old videos.
Thanks for the awesome write up, glad you appreciated it, I’ll let you know when I destroy the car!