Desktop Siege Weapon: Fireball Cannon

Looking for a harmless way to really step up your office warfare game? Why not build a nitrocellulose desktop cannon!?

On of our favorite science DIY YouTube channels, [NightHawkInLight] shows us how he made this awesome cannon — with interchangeable cannon cartridges! It even has a bit of a steampunk feel to it.

Nitrocellulose, or flash cotton as it’s more commonly known, is used by magicians for fireball magic tricks. Similar to flash paper, it burns up very fast and leaves almost no ash or residue. Creating the fireball effect is as simple as igniting it inside a tube — expanding gases take care of launching it out quite violently.

All the action is in the 3/4″ copper tube cartridges that come complete with home-made glow-plugs made from nichrome wire harvested from a broken hairdryer. These interchangeable cartridges allow [NightHawkInLight] to load up ahead of time and fire them off in quick succession.

Alternatively you can make a wrist launcher for these too — it’s a bit safer than an all-out-flamethrower…

16 thoughts on “Desktop Siege Weapon: Fireball Cannon

  1. my concern would be someone putting something in the cartridge after the nitrocellulose. At best you have an expected projectile at worst the cartridge could fail. I think this might warrant some testing :)

    1. Yes. If you put “something” in the cartridge after the nitrocellulose, then that something is what we call a “bullet”, and what you’ve got here is what we call a firearm. There’s a reason nitrocellulose in this form is usually called “guncotton”.

      1. The problem being that thin walled copper pipe doesn’t handle pressure as well as a much thicker wall of steel and confined nitrocellulose makes scary pressures easily, so loading a bullet can turn this thing into a pipe bomb :P

        1. Actually drawn copper can have a higher failure point than some mild steels, but what will fail are the solder joints, epoxy and “stuff” that holds it together, which at that point we call “directed shrapnel”.

          Experiments conducted in the 1960s with firecrackers and soldered tubing proved that after several shots the structure would suffer catastrophic failure, dissuading the experimental staff from futher firearms development at least until they got out of middle school.

  2. Could you make a rig that holds maybe six of these “cartridges” in a ring that can rotate, so that a number of shots can be done in rapid succession before having to reload? That would be even cooler.

  3. Radio Shack used to give away a five D-cell metal flashlight for free with a coupon found in the Sunday newspaper back in the 70’s. In subsequent years, RS got cheap and changed out the metal flashlights for plastic ones.

    These coupons were available in abundance because two of us (not me) delivered newspapers door to door, and would appropriate as many Radio Shack Sunday ad inserts as possible to obtain a stockpile of flashlights.

    We would unscrew and remove the reflector assembly and toss it in the trash. We kept the plastic screw ring simply for cosmetics.

    On the back end, in the vicinity near the lip of the metal endcap that gets removed to insert the batteries, a tiny hole was drilled into the barrel.

    A firecracker is inserted into the base of the flashlight with the fuse exiting the tiny hole. The endcap is then screwed back on. A ping pong ball is dropped into the open end of the flashlight, rolling down to rest atop the firecracker. .

    Ignite the fuse and take aim.

    Anyone standing twenty to thirty feet away wound up having welts after being struck ‘through clothing’ by the cannon ping pong ball.

    Oh, those were the days!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.