[hw97karbine] has made a pretty cool tennis ball cannon. While making a cannon of this sort is nothing new to us, we were impressed by the effort taken to get a stoichiometrically ideal mixture of 3.2% butane and air in the combustion chamber.
[hw97karbine] filled a syringe with butane and then dosed exact amounts into the chamber using a hole in the back. To control the air mixture he marked lines on the outside of the cylinder with magic marker. Simple but effective.
More rewarding than the methods was the cool slow-mo videography of the explosions in the chamber. You really have to check it out. [hw97karbine] shows clearly the difference between a well-balanced fuel to air mixture and a poorly balanced one. It’s one thing to say that more fuel does not mean better combustion, as we all remember from our personal potato cannon experiences, but it’s another thing entirely to see it.
If your local surplus store is fresh out of supercapacitors but you’re just really in the mood to fire stuff at other stuff, check out [austiwawa]’s step-by-step guide to building a thermal cannon. It shoots whatever will fit into a 1/2″ copper pipe, propelled by cut-up matchheads and lit by a propane torch. [austiwawa] demonstrates it by firing an AA battery at an unsuspecting pumpkin. For what it’s worth, we don’t necessarily condone applying this much heat to alkaline cells.
[austiwawa] used a copper pipe for the barrel because it provides the fastest heat transfer. One end of it is flattened and folded over to form the propellant chamber. A couple of packs worth of match heads are tamped down into the folded end with a paper towel serving as wadding. [austiwawa] tosses in his battery, lights the torch, and then runs away.
This whole dangerous contraption is secured to a wooden base with a u-bolt and a couple of pipe straps, and suspended between more pieces of wood with a length of threaded rod for stability and aiming.
We’ll let the safety-conscious readers do our work for us in the comments, but in the meantime, note that this thing is not safe. As [austiwawa] demonstrates, the copper gets brittle and will split open along the folded edge.
But kudos anyway to [austiwawa] for showing shot after shot of the cannon in action at the end of his video. You know where to find it.
If it’s a stronger, more beautiful barrel you’re after, just machine one by hand.
Continue reading “DIY Matchhead Cannon Brings the Heat”
CNC machine tools are getting ever more affordable for the amateur machinist, and they’re an enabling technology for many projects. But you’ve got to respect the old school approach to turning hunks of metal into finished parts with no computer control. [Ticktock34] shows off his skills on a WWII vintage manual lathe with a photo album of his .75 caliber miniature black powder cannon build. What starts as a 3″ diameter actuator from a front end loader ends up as a beautiful replica of a full-sized cannon, along with a half-filled barrel of nicely blued scrap metal. Particularly impressive is the nicely proportioned ball end, cut by hand with no more instrumentation than a set of calipers. [Ticktock34] also shares a few tips for getting the trunnions exactly squared and aligned.
Good looking, and functional – stay tuned after the break for a video with the impressive blast from a test firing – with only a quarter charge of powder, mind you.
Want something a little safer for the kiddies and less likely to result in a visit from the police? Perhaps this PVC pirate cannon is more your speed.
Continue reading “Miniature Cannon Packs a Punch, Shows off Manual Machining Skills”
This week, [Chris] tips the scales but ultimately fails. He’s on the road, hacking through the Great White North and improvising from a poorly-lit echo chamber that happens to have a vise.
Knowing nothing about firearms (do you believe that?), he decided to build a BB cannon out of pure scrap. Several kinds of sparks fly, starting with a Hitachi drill-as-lathe and ending with a tiny cupcake sparkler. [Chris] proceeds to bore out some redi-rod by eyeballing it and offers helpful tips for course correction should you attempt same. Having centered the cavity, he drills out a tiny hole for a fuse.
His first fuse is of the crushed up match head paste variety. It burns kind of slowly and does not launch the BB. Naturally, Plan B is to make napalm glue to adhere Pyrodex pistol powder to paper. As you might imagine, it worked quite well. The wadding was singed, but still no joy. After packing her full of propellant, it still didn’t explode and merely burned out the blowhole. So, what gives? Insufficient barrel length? Should have used bamboo instead of redi-rod? Didn’t want it badly enough? Give us your fodder below.
Continue reading “Fail of the Week: [Chris] vs. The Gorn”
If you’ve ever found yourself immersed in the wild realm of electronic dance music, then chances are you’ve probably heard [Flux Pavilion]’s dubstep banger ‘Bass Cannon.’ The music video released for the track shows [Flux] and his minion [Doctor P] performing twisted audio experiments on unexpecting research candidates by blasting them in the face with strong waves of sound vibrations, which blew back the hair of the people strapped to the chair. The audio trials took place inside what looks to be a warehouse filled to the brim with speakers, heavy duty subs, and sound boards; making it more like a ‘room of bass’ rather than a bass cannon itself. Yet, it inspired one of Hackaday’s Alum to literally create a bass cannon himself. And as you can see in the video below, his device packs quite a punch.
Most of us know [Adam Munich] as the guy who built this portable x-ray machine that could look through just about anything. He’s also built a nuclear bomb detector and has documented several radiation safety techniques, but every once in a while he decides to make something utterly ridiculous like this! He describes his homemade bass cannon as having a variety of fun and exciting uses including a mobile party on one’s shoulders, a way to frizz your hair, or an electrifying method to scare the neighbors.
Continue reading “Let the Bass Cannon Kick It!!”
Hackaday took a trip to Detroit last weekend for the Red Bull Creation Contest. It was a blast, we had a lot of fun, and we were lucky enough to catch a glimpse at seven teams hacking, grinding, sawing, and soldering their way through the 72 hour buildoff.
Team Detroitus started their build with the idea of building a giant air cannon. The theme of the build was ‘reinventing the wheel’, but they apparently didn’t let that get in the way of building a giant double barrel air cannon, filling it with candy and stuffed animals, and shooting it, point blank, at children. I was wanged by a lemon Starburst, but that’s my favorite flavor anyway.
Continue reading “Red Bull Creation: Giant Cannons Shooting Salt”
A team of mechanical and electrical engineering students at Olin College came up with a very fun semester project — a pneumatic powered marshmallow cannon that can track faces, and aim for the mouth!
The device — dubbed the Confectionery Canon — is an impressive mechanical build which required many of Olin College’s manufacturing resources such as the laser cutter, the mill, and the lathe. The majority of the device was made out of acrylic, which was chosen for easy laser cutting, and affordability. Specific aluminum pieces provide strength and were made using mostly scrap found in the shop.
Four servos, a webcam, a solenoid and an Arduino Uno make up the electrical system, which uses Python and OpenCV to track faces (GitHub). A PVC tank is used as the pneumatic reservoir, charged with a safety release valve at 30PSI. To fire the cannon, a sprinkler valve is controlled by a beefy solenoid. It currently only has a magazine capacity of 4 large marshmallows, but the team is planning on upgrading soon.
They have put together a great website with tons of information on the project, and following the break is a fun promo video they made for the project — they even got the VP of the college to try it!
Continue reading “The Face-Tracking Confectionery Cannon!”