Gifting is one of the 10 principles of Midbun (Israel regional Burning man) and a great way to give a gift is by hand it over with a cannon 🙂 The idea is simple yet impressive: Build an enlarged potato cannon, stuff it with flying/hovering/rotating LEDs and fire it. The LEDs would fly and drop like rain for couple of second and the participants at Midburn will collect it and use it at a night accessory. This is how it looks at the end:
I don’t have a video of it – we forgot to take one because of the excitement of firing it – but I’ll make one soon.
Unfortunately my idea wasn’t ready for Midburn 2015 (lots of projects.. hehehe) but few week later, Itzik Ronen and I managed to do it for Kinnernet 2015. The build log is simple, we used schedule 16 pipes like the one used in pluming for pools with high pressure water. We chose to use this kind of pipes because it need to stand the blast of firing it – when firing a potato cannon, the explosive material that makes it go BOOM is usually hair spray or other kind of spray that contains flammable gas.
The second issue was how to make all the LED copters fire at once from the cannon, in order to achieve that a capsule was build from disposable plastic drinking glass, we created cuts in the plastic in a pizza shape formation. This kind of solution was chosen because the plastic is harmless and disintegrated right after launch because of the launch combustion itself.
Usually the LED copter of LED flare is being shot to the sky using a sling shot:
Here is a look inside the LED cannon just before firing:
The cannon is made from two main parts, combustion chamber and a barrel. The two are connected via an adapter of 2″ to 4″: the 2″ is the barrel and the 4″ is the combustion chamber. At the end of 4″ pipe there is a screw-able cap so we could spray into the 4″ pipe the flammable gas. Special PVC cement was used in order to glue the parts together.
The ignition was made by using spark igniter (like the ones I used for the Spark2Sound project), 2 holes were made using a drill and 2 electrodes where installed inside it in order to create a decent arc-spark that will ignite the flammable gas.
Another picture of the cannon fires after two volleies, you can see the remains of the previous volleies on the tree and the shade top just below the place we were launching from: