Nerf blasters are fun and all, but they’re limited by the fact they have to be safe for children to play with. [Flasutie] faced no such restrictions when building his giant 40 mm foam dart launcher, and it’s all the better for it.
This thing is sizeable—maybe two to four times bigger than your typical Nerf blaster. But that’s no surprise, given the size of the foam ammunition it fires. [Flasutie] shows us the construction process on how the 3D-printed blaster is assembled, covering everything from the barrel and body assembly to the chunky magazine. Loading each round into the chamber is a manual process, vaguely akin to a bolt-action mechanism, but simplified.
It’s the method of firing that really caught our eye, though. Each round has a cartridge and a foam projectile. Inside the cartridge is a quantity of flammable HHO gas generated, presumably, from water via electrolysis. The blaster itself provides power to a spark gap in the cartridge that ignites the gas, propelling the projectile through the barrel and out of the blaster.
We’ve seen plenty of Nerf blasters and similar builds around these parts, including some with a truly impressive rate of fire. Video after the break.
Nice build. Nice video.
Where are the STLs?
obSafetyNanny: because it uses ignited expanding gas, it would be classified as a firearm in the USA
I see STLs for sale on his Patreon, actually.
Whenever I see one of these videos I’m thoroughly entranced, and slightly concerned. The XXL revolver is also fun. I’m personally not going to mess around with this stuff (though I’m comfortable with actual firearms) but from a legal standpoint, I imagine it would be hard for law enforcement to prove that the little plastic shell casings ever actually HAD hydrogen in them.
“I see STLs for sale on his Patreon, actually.”
Okay, I just watched the video, and didn’t look up his YT info.
In the USA, the line is actually “explosive” propellant.
If it was expanding gas, every bb, pellet, paintball, airsoft, and nail gun would be regulated.
The question, then, is whether HHO counts as an explosive? It doesn’t seem that the ATF covers gaseous mixtures.
The carbide and water (acetylene) canons are legal. Black powder canons are legal. Given the error bars of ATF decisions, an auto-loading gas gun?
That definitely would mess with the potential goofing around and fun that can be had with it.
At least it would be legal to own, since IIRC the US allows for people to make their own firearms. However, it’d make actually using it more likely to cause legal issues.
If this kind of thing does count as a firearm, you’d still have to be extra careful you don’t engineer something which could get into NFA territory. If I recall correctly, they don’t look kindly on semi-automatics which use electrical ignition or any kind of electronic trigger.
Because it uses a stoichiometric mixture of hydrogen and oxygen, I’d worry far more about deflagration to detonation transition.
Maybe by a strict definition you could call it a firearm, but I don’t think a jury would take that very seriously when shown a foam protectile.
Sure, but by that point you are in court, with all the associated time/money/opportunity costs, for making a toy.
Ok, US Law confuse me. Where does that leave a spud gun? That also uses ignited gas?
If it uses fire to accelerate a passive projectile, it’s a firearm. If it’s over .50 caliber with no sporting purposes, it’s a destructive device. (this project fits both)
Electronic ignition also falls in there somewhere. It might be classified as a destructive device or machine gun, I can’t remember.
Compressed gas cannons are not firearms (no ignition, no fire).
Earlier comments implied that black powder and acetylene aren’t classified as firearms, but they’re only partially right.
Black powder firearms fall under ATF control the moment an explosive primer is installed.
If you were to send the design files for this project to the ATF for review, they would classify the project as a firearm, and law enforcement in general would classify it as a “ghost gun”.
Just like how they classified shoestrings as machine guns, and brass wool as a suppressor.
The reason you don’t see the ATF enforce the laws regarding propellant spud guns is largely because of public backlash. If they could, they would.
All of this insanity is brought to you by a law passed to quell civil upheaval shortly before WW2. (national firearms act 1934)
You could mail order a tommy gun as a 16 year old prior to that law.
so many Americans that support our 2nd Amendment PRIVILEGE do not understand that the national firearms act 1934 removed part of the “RIGHT” and gave us a 2nd Amendment PRIVILEGE. In 1968 the gun control act completely removed any and all of the “right” that had not been removed in 1934. A “Right” does not have stipulations or is only available to a specific group of people. A “right” is acquired in full to everyone at birth. A PRIVILEGE is regulated, includes stipulations, limited, and can be removed at any time.
So close to having 3d printed battlemechs, continue the good work
Read headline. Skipped article. Straight to comments- yes. This.
This guy designs awesome stuff! Love his videos. He is a true engineer!
Like PEBKAC alluded to, I wonder how close this is to detonation. Shock front speeds over 3000 m/s, temperatures over 3600 K would be interesting when they encounter a thin bit of 3D printed plastic.
Fortunately (maybe?) the detonation pressure of stoichiometric H2 + O2 at 1 atm is low: around 18 atm. Easily held by a steel bottle. I’m not sure I’d trust a 3D printed containment vessel.
That said, despite its poor energy density it doesn’t take much oxyhydrogen to generate an impressive pressure wave: A small garbage bag full can blow a window out of a garage. No, you don’t need to ask how I know that.
A Li-Ion pouch battery, a small garbage bag with the exact quantity of water to be electrolysed, and a simple tesla-coil-like or piezo for detonator, the whole thin you can slide it under a door, remote start the electrolysis, then detonate it ?
That leaves almost to no traces except the device with its battery…
Fun, reminds me of this bit of video from years ago, a bit long but worth it for the punch line.
https://youtu.be/ib8StpzyxDE