Your Fingers Will Never Leave Your Hands with This Firecracker Launcher

Who doesn’t like to ring in the New Year with explosives? But speaking from personal experience – I can neither confirm not deny nearly blowing my hand off once with a small dry-ice grenade – a hands-off way to launch your fireworks can be a plus, in which case you might want to check out this automatic firecracker launcher.

[Valentin]’s build has all the earmarks of an inspired afternoon of hasty hacking. Mostly built of wood and hot glue, there’s a feed ramp for fresh ammo and an elastic-powered sled on a ramp. Fireworks are metered onto the sled with one turn of a small gear motor, the fuse is light by a butane torch, and another gear motor pulls the sled back and launches the firecracker. The launch is somewhat anemic – perhaps some stouter rubber bands or latex tubing would provide a little more oomph. But it’s still a fun build with plenty of potential for improvement – perhaps something along the lines of this automated beer catapult?

25 thoughts on “Your Fingers Will Never Leave Your Hands with This Firecracker Launcher

  1. it’s super cool. would probably wanna protect the electronics incase one rolls off the back end there and onto the arduino. i dont think they’re hardened against fire cracker

  2. That’s a contraption to be proud of.

    But I’m still gonna ask. Are the fireworks being thrown actually powerful enough to warrant this? Could they do any serious damage to the hand, assuming you’re not foolish enough to close your hand around it?

        1. That’s not the part number ;)
          That is the approval number of the German Bundesamt für Materialprüfung (BAM, Federal Institute for Materials Research and Testing).
          Firework in Germany has to be approved by the BAM so that it meets the safety requirements.
          Only approved fireworks are allowed in Germany.

      1. Not with German BAM-Tested fireworks. A burn? Yes. A separated finger? no. Anything powerful enough to separate fingers won’t get the BAM-PII-xxxx tag. The xxxx identifies the manufacturer, BAM-PII-0279 being Class 2 firework made by Comet Feuerwerk GmbH.

    1. Having worked in the medical field for a while I can simply say, yes!
      Generally people are holding the firework between at least two surfaces, index and thumb are common. And lighting the device with the other hand or object. When you go to light or toss the firework the fuse is sometimes too fast for human reaction and the result is instantaneous amputation by explosive force even for small devices. I have yet to see anyone try and light a firecracker with an open hand. Part of the problem is firecrackers generally contain flash powder not black powder or gunpowder and its much more powerful per unit of mass.

      https://en.wikipedia.org/wiki/Flash_powder

      “This makes flash powder dangerous to handle, as it can cause severe hearing damage and amputation injury even when sitting in the open. Self-confinement occurs when the mass of the pile provides sufficient inertia to allow high pressure to build within it as the mixture reacts.” and “Beginners should start with sub-gram quantities,”

      To summarize a small pile open to the air is subject to inertial confinement and will explode with considerable force and report. Thus even having a small pile in your open hand is going to go BOOM not FZZZZ WOMP like black powder. This is why even small devices will remove your valuable appendages.

      1. This is true, and a good description of the difference between deflagration vs. detonation. But it’s still a matter of quantity.

        For example, there’s such a small amount of mercury fulminate in a “bang snap”, that event though it detonates, it’s incapable of causing damage even if sealed tightly between two fingertips. Have done this many times, can’t even feel it.

        And a cheap dime-a-dozen firecrackers can apparently be held in a two-finger pinch without serious damage. Well maybe, at least some of the time. I’ve lit and thrown my share, including for fireworks fights, but still wouldn’t *intentionally* let it go off in my hand like this kid:

        M-80? Nope, I’d never light that in my hand, period. At least in the US, such fireworks are no longer available, and others have been nerfed to near harmlessness.

        I’ve never seen a BAM-PII-0279. It’s hard to judge how powerful it is from the video, but it looks rather weak for its size, and it doesn’t move any dead leaves next to it that I can see. It’s probably better not thrown by hand, but I’m still curious whether an accident would be likely to cause serious injury or not. Even though I don’t plan to risk it, or recommend others do so. A lot of what we do as hackers requires some amount of risk, and being able to properly estimate the risk; so it’s useful to test your estimates more frequently than you actually have to rely on them.

        1. BAM-P2-xxxx is the “tag” of the german Bundesamt für Materialprüfung (BAM, Federal Institute for Materials Research and Testing), saying that this is Class 2 firework, permitted to be used by the general public with no certification for explosives. That thing won’t blow off any appendages, anything that could won’t get the BAM-number.

        2. Quantity, very true, what I was trying to say is that the quality of flash-powder needed to to harm is much less then most people realize especially if you have used black powder or smokeless powders for science projects.

          There was a time in my life I took all of the bang snaps in bag, unrolled them all and put them in a larger bag (usually the bag that held them in the first place) and carefully warped a twist tie around the top of the pile to make a “big” snap out of one box, when I blew a hole in the lawn several inches deep and wide, I decided that was a VERY bad idea, yes 1 bag of snaps, put in a single pile is more then enough to remove body parts as you said its about quantity and we know how exact the Chinese are measuring things when it comes to mass production.

          While making one of the above I tired to use a glass spice jar to temporarily hold the rocks as I used a folded piece of paper like a funnel to pour the unwrapped bits into the bottle a few at a time. As the pile grew in the jar something happened, it spontaneously went off in my lap between my legs. Out of pure luck I still have my genitals and my eyesight. The last thing I saw was a yellow flash, a loud report, and felt a thousands of tiny hot rocks blasting my face, the glass spice jar surprisingly did not shatter as it sat next to both of my femoral arteries, my eye site saved by my glasses that received dozens of scratches, my face was peppered with black pits. In retrospect it must have been a comical sight, while incredibly stupid, I can picture the shotgun effect and flash that must have occurred. Looking in the mirror was a sight! But the end result was that even “safe” fireworks are not always so.

          And now we have YouTube for immortalizing stupidity for all to see.

          1. Ack! Glad you suffered no serious injury from that.

            Yep, the dangerous quantity really is small. I normally don’t mess with explosives, but curiosity got the better of me with ammonium tri-iodide as it’s a unique one which I’d never seen demonstrated in person. So I made what I *thought* was a trivial amount. Trying to trigger a fraction of the batch, I found I was unable to do so, and assumed I’d screwed it up. So it all went in the kitchen trash.

            Turns out that although it was visibly dry, it wasn’t dry enough to explode. It become so in the trash. And when I threw something away the next morning, still half asleep, I got a big surprise! Woke me up for sure, and left my ears ringing for a bit.

    2. An m-80 will take your fingers off and damage your hearing. We never thrown m-80s we set them in a spot or a hole in the ground and light them where they stand and run, This is a wise thing to do since none of your appendages are in contact with the explosive.

    3. A properly made M80 will cause injury (burns, maybe some lacerations) if it decides to go off while you’re still holding it…
      If (for whatever stupid reason) you hold it with your fist clenched around it, serious (surgery necessary) injuries will occur…

  3. Fireworks are illegal in most parts of Australia, but back before the Fun Police took over I was told the way to hold fireworks was: at the base. Pinched between tip of thumb, and tip of forefinger.
    The smallest fireworks of my youth could be held like this until they went off. Larger ones, when lit, were thrown with a flick of the fingers.

    This design looks nice, but for spectacle (and throwing distance) I’d suggest some form of trebuchet. Hand load the firework, then have a mechanism light the fuse while the trebuchet is swinging.

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