A new friend in the 501st Legion is helping to build a very clever booth game for the Star Wars booth at an upcoming ComiCon in my area. He build a Death Star trench using vacuform plastic tiles on top of plywood frames on top of PVC legs – very modular. 2 strands of fishing wire are stretched across the 22 foot length of the trench to allow a modified RC X-Wing toy to “fly” down the trench. The X-Wing has a servo at the bottom that holds a “proton torpedo” (aka LED in a plastic ball) that can be dropped. The whole thing is controlled by a Spektrum DX6i controller. The build is spectacular and he’s been working on it for months. “Most Impressive” – Darth Vader
The target is about 3 inches in diameter. Considerably smaller than a 2-meter womp rat.
When the call went out for help, I jumped at the chance. I ran over and helped do some finishing touches. Overall it looks great, I think kids (and adults) will love it at the con. Best of all, the proceeds that will be charged for attempts will go toward a great charity. The 501st is really good about that kind of thing.
So, being the maker that I am, I left from the build day inspired and wondering what more I could do to help make the build great. I had a few ideas and got to work as soon as I got home. The build was done over a 36 hour period and used scraps I had lying around (zero out-of-pocket cost, or lead time for delivery). It was so fast, in fact, I forgot to take some build pictures 😦 Oh, well – you’ll get the idea.
Because of the perspective of the pilot, some sort of warning would be nice when you’re approaching the drop point. I remembered I have a “learn to solder” kit from Ramsey that is a laser tripwire. Breaking the laser beam will cause a relay to close. It would be cool if it could make something light up or play a sound effect.
Obi Wan Kenobi: “Use the Force Luke, let go…” (encouraging the release of the bomb)
I have a left-over Adafruit Audio FX Sound board that I tried to use with K-9. Unfortunately, the serial connection was not supported in the version I bought, but it still works fine for basic I/O. It has 11 I/O pins so I could play up to 11 sound effects. The laser tripwire could be 1 of those pins. What else could I use?
It would be nice to have a sensor in the “Exhaust Port” to help the booth operators identify a direct hit. Something that makes an explosion sound.
I’ve learned from experience that the “please don’t touch” request is hard for kids, and often ignored. So, what if I could create some control panels that have switches, and buttons and knobs that we could invite the kids to play with. As part of the experience, I could make them look like the inside of an X-Wing cockpit. Some of the momentary switches could be used to trigger other sounds on the FX Sound board.
I’m thinking it might even be fun to convince some of the kids that all the switches are live, and get them to fiddle with them in hopes of getting the settings “just right” in order to achieve the goal and win the prize. If nothing else, it might get a few to come back and try again with different switch combinations. 🙂
So, this was very quick build, but here’s how it went:
- Found a scrap piece of black 1/4″ PVC board (12″ x 12″) from a Plastic Selector Pack from McMaster-Carr (great inexpensive way to see the differences of the different types of plastic they offer). Cut it in half on the bandsaw.
- Visited The MovieWavs Page and downloaded .WAV file clips from Star Wars Episode IV (this site has almost the whole move in small .WAV files) . Loaded them onto the FX Sound Board and tested.
- Dug into my parts bins and found a bunch of left-0ver switches and knobs.
- Used Easel and created a quick design to cut out shapes in the plastic with my X-Carve (after several practice runs on wood to get the size just right).
- Popped the switches and knobs into the board and screwed/glued them down.
- Wired them up, and soldered everything down
- Used some surplus wire to connect the 2 boards together using available connectors for easy dis-assembly. (RJ-45 connector, 4-wire PC connector, etc. – whatever I could find that would only allow the wires to be attached in the correct way)
- Build a small box for the boards out of scrap wood. Sides were 3/4″ pine, bottom was 3/8″ plywood, and the front was a nice piece of 1/2″ Cherry.
- I routed notches in the pine to allow the board to slide in, and rounded the Cherry front for a nice finished look.
- Painted the box white
- Assembled the unit and tested. Everything worked on the first try (I swear, that never happens).
I was in such a rush, I didn’t even take a video to show it in action! I’ll be sure to grab some footage at the con. It’s a bit loud, but at the con, it will sound fine since it is often VERY noisy on the con floors.
Some of the audio clips I used were chatter among the pilots from the scene in the movie where they were attacking the Death Star (Stay on target! Stay on Target!). Others, I had to modify a bit (using Audacity). The sound clip that plays when the target is hit is a set of sound clips:
- Proton Torpedo launch
- Death Star Explosion
- Han Solo “Great shot kid, that was one in a million!”
- Plays the music theme from the medal award ceremony at the end of the movie.
Someone else from the 501st is planning to cast some resin medals and will be giving them away as prizes for those skilled enough to hit the target. So, the music theme was selected to match that prize.
Overall, it turned out great, considering the short time and limited availability of supplies (makes me glad I’m such a pack-rat about these supplies – now I need to go out and buy more). I’m sure it will bring much happiness and earn some money for a worthy cause. I’ll post more pics and videos after the con.
We also built some simple rolling carts for transporting the trench pieces. The trench breaks apart into 6 pieces. Placed bottom-to-bottom, we added some short legs to connect the pair so they can be lifted. One of the 6 wheels on the cart locks to allow safer loading and unloading.
The Laser Tripwire approach was not going to work because the platform was not stable enough and there was too much risk of mis-alignment causing the sound to be triggered repeatedly. Also, the IR sensor was too sensitive and could not be tested in sunlight – we were concerned that the convention hall would have similar issues.
As an alternative, I came up with a quick solution using an Arduino and a Parallax Ping sensor (ultrasonic distance). This will address the issues of mis-alignment and light interference.
The Arduino will be hidden under the platform, and the Ping sensor will be mounted inside the trench. When the X-Wing “flys” by, it will trigger the Ping sensor and close the relay which will trigger the sound clip “Use the force, Luke”.