In part 1, I created a cannon barrel out of a concrete forming tube and foam insulation. To finish off the cannon barrel, I added 4 orange LEDs (part number 465-1417-ND) I picked up from Digi-Key. They offer free shipping if you pay with a check or money order, which makes it easier to make smaller orders with them. I wired up the LEDs with a 330 ohm resistor paired with each LED and hooked each LED/resistor pair to a different output pin on a PIC, which means that each such circuit is being powered by 5 volts when each output pin was turned on.
At first, I had difficulty finding a way to make the LEDs provide any significant lighting. Then, instead of shining them towards the muzzle, I tried shining them away from the muzzle. Since there wasn't anything for the light to reflect on in that direction, this didn't work either. Then, I cut a piece of cardboard from a cereal box into a circle slightly smaller than the inside diameter of the barrel, cut a similar size piece of white paper, and glued the paper onto the cardboard. I stuffed this in the barrel not too far from the muzzle (maybe 6 inches). This gave the light from the LEDs something to reflect on and proved to be a much better effect.
Now that I had the barrel of the cannon pretty much done, I needed a carriage for it to rest on. I bought a couple of 2 foot by 4 foot pieces of lauan plywood from Lowes. I cut both of them down from 4 feet to 3 feet. Then, I cut a pattern into each piece that I copied from bastardrat.com. Since the plywood wasn't very thick, I added some framing to it. I used 1"x3" strips at several places along the plywood. I used both wood glue and nails to attach the strips to the plywood, and I used nails to connect the joints. My carpentry skills are not very good, so the sides ended up being not quite square with each other, but it was close enough for my purposes. Here are a couple pictures of the inside of the carriage. Click on either picture to get a larger version.
And, here is the final version. I probably should stain the carriage eventually, so this may not really be the final version, but it's the final version for 2009, anyway.
And, here's a 12 second video of the cannon in action.
Cannon firing (5MB)
Page last modified 11/09/2009