Military models are great 3D printing projects, even more so if they are somewhat functional. [Flasutie] took it a step further by engineering a 3D-printed howitzer that doesn’t just sit pretty—it launches shells with a hydrogen-powered bang.
This project’s secret sauce? Oxyhydrogen, aka HHO, the mix of hydrogen born when water endures the electric breakup of electrolysis. [Flasutie] wanted functional “high explosive” (HE) projectiles to pop without turning playtime into emergency room visit, and 30 mm was the magic size, allowing the thin-walled PLA projectile to rupture without causing injury, even when held in the hand. To set off the gaseous fireworks, [Flasutie] designed an impact fuze featuring piezoelectric spark mechanism nestled within a soft TPU tip for good impact sensitivity.
The howitzer itself is like something out of a miniaturized military fantasy—nearly entirely 3D printed. It boasts an interrupted thread breech-locking mechanism and recoil-absorbing mechanism inspired by the real thing. The breechblock isn’t just for show; it snaps open under spring power and ejects spent cartridges like hot brass.
Watch the video after the break for the build, satisfying loading sequence and of course cardboard-defeating “armor piercing” (AP) and HE shells knocking out targets.
Have to agree, but at least this one is actually a hobbyist making a thing and not just a puff piece for the military industrial complex. Those are weird.
Yeah.
Honestly, if they reposted Forgotten Weapons videos in addition to the several youtube channels they scrape, it would contain a lot of inspiration for mechanics, simplicity in engineering, & multifunctionality which have applications far beyond guns. And interesting history lessons to boot.
Explosions can be fun.
https://youtu.be/ZhXb9qXTvzI
Jarvis, upscale schematics by 300% and fire up the lathe
This is Darwin territory.
There’s not a great distance between “satisfying pop” and “laceration-inducing shrapnel” when Brown’s gas (HHO, 2H2O2, etc.) is involved. It doesn’t just burn nicely like (say) gunpowder. Depending on the mixture, pressure, container geometry and size, it can easily transition from a gunpowder-like deflagration to a supersonic detonation, producing destructive shock waves. And even if it stays subsonic, a soccer-ball-size bag of the stuff will blow the window out of a garage. (Yeah, you don’t need to ask how I know that.) I maintain it’s called “Brown’s gas” because that’s the color of the stain in your shorts when it goes a bit sideways.
2H2O2 are two moles of hydrogen peroxide. The reaction equation is written as follows:
2 H2 + O2 → 2 H2O
“Brown’s gas” and “HHO” are terms for oxyhydrogen originating in pseudoscience (according to wikipedia).
Hey, I’m not the marketing wiz who came up with the names for what’s just a near-stoichiometric mixture of hydrogen and oxygen.
And you forgot the most important part of the reaction equation:
2 H2 + O2 → 2 H2O + 484 kJ
It’s that last part that makes the kaboom and blood loss (and also powers the RS-25 and RL-10 steam engines)
I’d wanted to have you for my chemistry teacher!
I forgot nothing in the reaction equation. The thermochemical equation is written separately: ΔH – rxn = – 484 kJ.
The RS-25 and RL-10 are rocket engines, not steam engines.
Of course they are steam engines. Hot water vapor. That’s what produces their thrust. They *run* on steam. Their fuel is hydrogen and oxygen, but the work they do is done by expansion of high pressure steam. They are steam engines.
If you’ve never gotten gunpowder to detonation, you are lame.
For that matter, owning a ballon, a match and an oxyacetylene tank set is fun for all the kids.
Awesome
By that argument so is something like operating a welder, steam engine, table saw… Basically anything that has some chance at serious injury, which is almost everything more than a paperback book…
So yeah, not really a good reason not to do something – it is only if you don’t know how or don’t do the research and/or guided practice before you really try to do it without skilled help on hand it is really darn dangerous. In this case the design seems pretty sound for safe play – There is not much volume of gas to go pop and almost no mass for it throw even if there was and it did go pop rather violently – not exactly can never ever under any contrived circumstance hurt you, but equally safe enough as long as you actually treat it the whole process with a little respect.
This is not a hack. This is a professional model builder making a quasi-functional weapon. Not cool HaD.
So, you’re saying that if a professional makes something it should be removed from these pages?
All those projects and circuit boards made by people with electrical engineering degrees need to be removed. All the 3D prints by people with graphic design degrees. All the university projects that get featured. All the code libraries and projects done by people like me who work in software development.
Honestly, just to be safe, we should remove the few articles that would be left over, since they probably had help from a professional in some way.
A professional doing a project and creating a professional looking result shouldn’t exclude it from eligibility to this site.
I can’t stand the “This is not a hack” anymore. Hacking goes far beyond sticking a few things together with hot glue.
I agree, this isn’t a hack.
It is a good way of getting a visit from the ATF. Or your country’s equivalent.
“… this isn’t a hack.”
Nonsense. Unless this guy just printed someone else’s files, this project is a fantastic example of design, problem solving, and basement tinkering. It’s funny how the definition of “hack” has devolved to “a project that doesn’t offend me.”
The warnings (other comments, elsewhere) about the physical dangers inherent in this kind of project are well-founded. It’s certainly not the kind of thing I’d mess with, and it’s not something I’d recommend others do.
On the other hand the risk of permanent injury, while real, is not really greater than the risk from messing around with 10-watt lasers, 20kv power supplies, or robotic lawn mowers…all of which have graced these pages.
As to your remark about the ATF… I concede you may be right. But your observation says more about the dystopian police state we live in than any menace to society represented by a plastic toy.
Agree
agree 100%. love content like this
Spot on. Don’t let your logical mind muddled with your political view.
Funny how you mentioned the word hack. When I was young”hack” was a guy who did crappy work or was able to use unconventional way to perform something. Like using a matchbook cover to set your points in the distributor.
Mostly used as a bad reference for someone doing crappy work.
Now it seems to mean anytime somebody does anything like using vinegar and salt to clean a penny. Not a hack just plain chemistry.
The term you’re looking for is “field-expedient”.
Most “hacks” on HaD are just making stuff, in the way stuff is typically made by hobbyists using typical tools and processes. There’s rarely anything clever or novel about them, besides the fact that they got it first before the Youtube algorithm suggested you the same video.
I think the way ‘hack’ as a word has evolved recently is kind of interesting in its own right.
Though context is always king as well, same word with different meanings in different fields it the same period of time – most of us probably learned a hack in the computer/electronics (and probably a few other engineering type) context is most likely a sign of real understanding, competence and lateral thinking. So likely considered good/neutral depending on the context that hack is involved in. But in the same era of English ‘a hack’ in just about every other context seems to be the crappy low quality work end.
Where now hack to some extent doesn’t seem to really have a meaning at all, its become more synonymous with the act of doing just about anything. Which perhaps speaks to the need to ‘hack’ and actually think and do stuff for yourself rather than meekly accept the spoonfeeding and doing only what you are ‘allowed’ to…
>is most likely a sign of real understanding, competence and lateral thinking
Or lack of understanding and dumb luck, leading to magical thinking.
E.g. turning your optical mouse upside down and switching on the ceiling fan to generate repeated interrupts and force the CPU to switch tasks (before pre-emptive multitasking was common), because this makes the progress bar on your monitor tick ahead faster. Now THAT is a hack.
In virtually all of the US, it is entirely legal to build your own firearms (where 80% lowers come from), so unless he’s selling completed minatur cannons, he’s in the clear there as well.
Sorry, we ran out of things to install doom on, while 3d printing things might not be a hack, its at least adjacent to the interests of many readers. By the way, there is absolutely nothing illegal in this video, it would be absolutely legal to do this in all 50 states.
I’m a big fan. This is a great build and good fun.
“Weapons” are tools. They serve a useful purpose, like stopping home invaders and occasionally fascism. And like any tool – including the humble screwdriver – they can be abused by bad people.
Thumbs Up
While there is some truth to what you are saying. Screwdrivers don’t kill thousands every year. It’s silly to compare them so concretely.
Well, some folks in the USA say there more deaths from hammers than assault rifles:
https://www.washingtonexaminer.com/opinion/1483986/hammers-are-used-to-kill-more-people-than-assault-weapons-each-year/
@Paul LeBlanc
Totally agree. Bad math + statistics abuse.
I should have added a disclaimer.
Poky stuff is used to kill roughly 1500 a year. Blunt force weapons like hammers and baseball bats over 500 every year. Long guns (so all rifles) roughly 500.
Cars 43,000
Just wondering if the Italian mafia or Russian mafia has ki!!ed more with concrete, with or without screwdriver.
Good hack. Needs rifling or fins.
The barrel is rifled, arbitrarily.
It was rifled, for aesthetics.
3D printed plastic wouldn’t be able to confirm to the rifling anyways.
Why not? The ridges in the projectile could be formed in the printing.
Nothing wrong with covering projects like this. No need to spread hate every time technology or projects remotely related to weaponry is discussed.
This would get you cell time, where I live.
Connecting to the internet would get you cell time, where I live.
I use my cell to connect to the internet all the time.
If I say gaol, some might know what I mean.
Move or stop complaining.
Kids.
You’re triggered by a toy artillery piece?
I wonder if you’ve ever commented negatively on a HAD story with a drone in it…. if not, you’ve clearly not following the Ukraine conflict and the deadly effect to which they’ve been applied there.
So where is your threshold of indignation? Hammers? Rocks? All are weapons, I submit. Stalin starved millions, on purpose. It turns out that bread is a weapon, too.
The model is cool but I personally think that I have enough war related content through the normal media channels, I would like HAD use this space to promote other topics, like agricultural hacks, again that is my personal opinion and my personal taste.
Just pretend it’s being used to safely trigger avalanches. If anything that could be used in war were banned, we’d have to get rid of pretty much everything. Definitely none of the drone, radio or imaging hacks for a start.
18 U.S. Code § 921 – Definitions – LII / Legal Information Institute
The term ” firearm ” means (A) any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosive …
… and?
even assuming this creator is in the US, and even assuming this project meets the definition of “weapon”, US federal law still allows the manufacture of firearms for personal use.
(this should not be taken as a criticism toward any other argument about whether this project is/isn’t appropriate, dangerous, or legal in any other context. I personally think it’s interesting enough to belong here and no more dangerous than a lot of other things featured on a regular basis. but I understand why you might disagree.)
This is a great take on the classic potato cannon projects, thanks for the write up Danie!
The shrapnel has me a tad worried after my own irl experiences. I’m not sure what material would be “softer” and less sketchy than PLA yet rigid enough to not jam up. TPU with internal structural ribs?
Pretty cool. Not sure whats up with the commenters above I personally think this sort of stuff is cool. Yes war, weapons woo woo ahh ahh and all that call me whatever you want.
But seeing a guy make a functional model howitzer (with boom flash rounds) is cool as hell regardless.
Not sure whats up with the rest of you weirdos.
“Weapons scary. Boom booms make me scared.” I think you cry babies are a joke. I’d rather take bullet than be sliced to peice by a kitchen knife. Nerds nerding out.
Or have acid splashed in my face
dont be such a rube
You’re going to have an aneurysm if you search the “nerf” tag on hackaday and find a 3D printed dart blaster that shoots 100 darts per second.
This project is an excellent example of designing various parts of a real world system for use in a 3D printed design. The mechanisms, locking lugs, 3d printed gas shocks for dampening, there’s so much cool designing here!
Everybody who says this is going to get your door broken down by the ATF is insane. Do none of you remember potato cannons taking over all maker stuff in the early 2000s? All the automated dart turrets after the release of Portal?
DARPA is looking for a few good men. Looking for a job?
Wow I skipped to the end and saw that the thing managed to blast through three entire pieces of cardboard. Well two and the projectile wedges into the third.
.
What a weapon of war.
.
Definitely worthy of fear
.
Lol
.
I despise war and American gun politics, but my opinion is that guns can be one of the most interesting concepts when it comes to mechanical engineering. And this is certainly a very interesting and well thought out build. I don’t get why we are supposed to drop a very fascinating part of the hacking culture because folks over the pond cant stop shooting each-other?
” I don’t get why we are supposed to drop a very fascinating part of the hacking culture because folks over the pond cant stop shooting each-other? ”
Just curious….. Which side of the pond is the one that can’t stop shooting?
Those who have not swords may still die upon them
What’s funny is that this is probably a couple federal ATF violations (it shouldn’t be)
Honestly it’s funny that this place doesn’t include the most interesting use of 3d printers
Where are the STLs though? I would happily pay some $$, but I googled and clicked around and came up empty :(
30mm is also likely chosen for legal reasons (i.e. “No, officer, this well under the limit and is legally a flare gun and not a grenade launcher.”) I concur with those that don’t think this likely to get ATF attention. Getting municipal trouble, especially in certain Californian cities, maybe (although a slingshot or even a Nerf Gun will accomplish that depending on which legally illiterate bureaucrat or intern you get that day), but likely not federal or state trouble (in the United States anyway, don’t know about any other jurisdictions).
Sorry, but this -> “It is a felony to possess, manufacture, import, keep, offer, or expose for sale, give, or lend any bullet that contains or carries an explosive agent.”
From here:
https://www.ojp.gov/ncjrs/virtual-library/abstracts/when-ammunition-illegal
Not only are you not citing a law, you are citing a 30 year old magazine article. Anyhow, that law refers to California Penal Code 30210.
The ATF considers anything with a propellant charge of under 4 oz to not be a DD.
Thanks for the clarification.
I think you mean under 1/4 (one quarter) oz?
I.e:
https://www.atf.gov/firearms/firearms-guides-importation-verification-firearms-national-firearms-act-definitions-1
Love it, I really wish I could download the plans and print one with a smoothbore and design a sabot round for it!
Checkout the other videos from builder, there are several sabot round (AP*DS) builds:
https://www.youtube.com/@Flasutie/videos