The T-Shirt Cannon Broadside (Part II)

When I last left off with the T-shirt cannon project I had just finished talking about completing the three air cannons. With the air system done we needed a better firing mechanism. As you could probably tell from some of the earlier photos, the wiring job I did hooking the batteries and switch up to the test cannon was pretty sloppy. I called in the aid of my co-worker and friend Justin to help with a new and improved electrical system. In order to make the system safer I wanted to make a control box that could be several feet from the cannons and have a  arming switch for each cannon. The batteries would also need to be beefy (24VDC needed to fire each valve) so that we wouldn't burn them up after a few hours of use. Finally, the control box needed to look sexy... 'cause why not. Justin and I took a trip to Home Depot and got four 12V lantern batteries and speaker wiring. Then to Radio Shack for switches and a project box. After several hours of Dremmel and soldering action we ended up with this guy. We also discovered that a Redhook Beer cardboard six pack carrier worked perfectly as a holder for the four lantern batteries AND gave us an excuse to empty a six pack (Hooray for Beer!).

After the electrical system was done, the next step was to come up with a way to decorate the launchers to look like actual cannons. Fortunately, my roommate Neil was an art major in college. We spent a few days debating the best way to go about making the cannon shells. The original plan I had in mind was to carve a complete cannon body out of sheets of carve-able foam from Michael's Craft Store to make positive molds. With the positive mold we could then make a negative mold in a box using pourable urethane foam. The resulting negative mold would then be used to cast the three cannon shells. After much discussion Neil convinced me that this route was too expensive and fraught with peril, having had many failed molds himself in art classes.

Instead Neil suggested a "mixed media" approach using cardboard tubes and sanded foam rings. The idea being that your typical cannon has a front and rear chunk plus support bands. We could create these chunks by gluing together foam rings of different radii and then sanding the snot out of them. There would be three ring diameters: Small(S), Medium(M), and Large(L). So our cannon ring layout from front to back would be: LLMMS -- S -- S -- SMLLL. As for the main cannon body, I found the perfect cardboard tubes at Home Depot, which were originally meant for cement cylinder castings. For the foam itself, we used that rigid pink insulation foam that comes in 8' x 3' sheets. Anyway, after many painstaking hours of cutting, gluing, and dual-belt-sander-action at Neil's parent's garage we finally ended up with a finished product we were pretty happy with. Incidentally, if you ever have an art project that requires carve-able rigid foam I really recommend that stuff. But be warned YOU WILL GET FOAM PARTICLES EVERYWHERE, even in your eyes, even if you are wearing proper eye protection... just FYI there. Anyway, after the foam pieces were done we liberally applied some wall spray texture and then several coats of glossy black spray paint to give the exterior a pitted iron look. All and all, Neil and I were pretty pleased with how they turned out

While Neil and I had been working on the cannon shells, my boss Rick had been working on a fake ship exterior and base that the cannons would rest on. The ship side had to be simple and disassemble-able for transport. Rick's design called for a wooden base with wheels so the whole assembly could be moved. Two support triangles that fold up from the base then clipped onto a sheet of plywood with three 9"x9" ports cut out for the cannons. The port holes were lined with pipe insulation foam to protect the cannon shells from getting scratched. The audience facing section of the plywood was then decorated with a fake set of waves cut out from another section of wood.

Once all the pieces were in place it was time to assemble the full broadside in all it's glory and do a test firing at work. After lunch, we setup the cannons behind the office and invited everyone down to come and watch. Some of the folks from the content department were kind enough to help load of the cannons while others volunteered to catch shirts. I was a bit nervous demoing to a large group of people because Murphy's Law always seems to strike with an audience. And sure enough Mr. Murphy reared his ugly face. While charging the third cannon it fired the shirt prematurely, so the first round only had two simultaneous shots in it. While I inspected the valve assembly on the third cannon, we fired off a few more single shots. After some fenageling with cannon #3 Justin and I figured out that the quick release switch on the sprinkler valve was popping open when the valve was under pressure, but it was nothing some quick work with duct tape couldn't fix. After the cannon mod we were able to get all three cannons firing simultaneously... and it was awesome. All that was left was to make some touch ups to the exterior. Later that night the Art Department applied their magical painting skills to make the rig look more like the side of a ship by adding assorted detailing like froth to the waves.

Getting the cannons set up at PAX was a bit of a challenge as the we weren't quite sure where the best place for the cannons to be all while trying to get the rest of the booth setup. Our booth layout was a 25'x25' square with computers at the perimeter and a big open area in the middle for staff, t-shirt storage, etc. After some back and forth we settled on one of the corners and pointed the cannons to fire over the opposite corner of the booth into a large crossroads where unsuspecting con attendees could "catch" the shirts. After a few mishaps (like the one seen in the YouTube video where we didn't use enough pressure, or when we hit CCG game players at the Blizzard booth after using too much pressure) we got our routine down. Tim, one of the devs, and Lindsey, one of the artists, both in pirate garb would prep the crowd with some pirate-y theatrics to let people know we were about to fire off a volley.

With all of the craziness I did feel bad for the booths next to us, especially the HotHead Games guys who were trying to do demos of their Penny Arcade Adventures game. It seemed like every time they were starting a demo, you'd here "READY THE CANNONS!" plus assorted yelling from out booth for about a minute. That said, the Privateer Press booth who was down wind of cannons enjoyed them quite a bit. I asked one of the guys working the booth if the cannons were a nuisance and he said, "Oh no we love those things! We actually had you guys fire some of our bandannas out of them earlier." They had been handing out these sweet pirate bandanna's, which paired nicely with our shirts :). He continued, "Oh yeah, you should have seen it earlier. There was this guy dealing cards at the WoW CCG and he was like 'one, two, three, four' then *FWAP* one of your shirts nails him right in side of the head and he pauses stunned for a sec, and then says 'OH SWEET!... five, six, seven...' like nothing happened. It was hilarious."

All in all, I was really pleased with how the whole project turned out. I was extremely fortunate to get all the help I did as it would have been nearly as awesome without it. Big thanks is owed to the following:

• Neil and Micheal for helping with designing, sculpting, and painting the cannon shells.
• Justin for helping me with control box, wiring, and assorted cannon support
• Rick for building the fake ship side
• Troy and Theresa for allowing me to complicate an already complicate booth at PAX
• Tim and Lindsey for their awesome pirate performance
• Bruce and the art department for painting the ship side
• Everyone else at FLS who had a hand in making the booth at PAX a success