A combustion potato cannon, every kid wants one, not everyone knows how to make one... this two-part video tutorial will show you how to make a standard homemade combustion potato cannon.
These step-by-step instructions will tell you everything you'll need to make this spud launcher that shoots potatoes at a speed of 600 km/h and at a distance of 200 m.
For the spark igniter: search eBay for "electronic spark igniter" sold by Sterling Products.
The fan: the chamber fan can be used for two things; the most important is ventilating your combustion chamber after each shot so you get fresh air into the chamber before stuffing a potato down the barrel. Next is to mix the gas inside the chamber once you have sprayed your combustion gas inside the chamber.
2 ventilation holes: if the mixture of the gas does not ignite or something is wrong, you can ventilate the chamber with something stuffed down the barrel.
Spark patent: the metal/plastic things attached to the wires is called cable shoes or cable rings.