Please excuse the terrible image quality, I don't have a better camera (yet).
If you've been lurking around at all, you may have noticed I was building a Guitar Freaks controller.
It's basically done. And here's the big secret:
I made the guitar out of K'Nex.
Full shot of the controller:
Another full shot:
Lateral view of the pick I constructed. It's composed of 45-degree gray connector pieces with a small bungee cord strung through the center holes to give it tension.
Another shot of the pick. God my camera really sucks.
Good shot of the fret buttons. They don't even require screws, they're just snap-in and I was able to make a frame for them out of even more K'Nex pieces. Notice how I added a "reinforcement" to the neck around the buttons here. This was planned but I took the initial pictures before I added that. It is also very necessary to prevent the neck from collapsing on itself as it's very easy to squeeze it while playing hard.
Shot of the body of the controller. You can see the Start and Select buttons; they're just cheap buttons I picked up at Radio Shack and then slipped between some of the connector pieces.
Another shot of the fret buttons, this time from the other side of the neck. It looks like the buttons are floating in the middle of nowhere and it appears flimsy, but trust me, it's not. It's mostly a camera trick.
Materials used:
K'Nex -- Lots and lots of K'Nex. I actually had to dismantle one of my older K'Nex projects to get enough materials to build this. (I'm glad I did, that old thing was an eyesore. But touch my Big Ball Factory and I will cut you.)
3 Sanwa buttons -- Part number OBSF-24KK, color-coded to match the Guitar Freaks fret colors. They are not as tough to push down as the usual GF arcade-style buttons, and a little bit squeaky, but they are the perfect size and shape, plus they snap into place and can be removed at any time.
Tilt sensor -- From a Something Awful forum goon that graciously donated it to my cause. I actually wired this up a little fancy: I jury-rigged my own quick disconnects using wire butt connectors, slipped the ends onto the sensor leads, and wired it up.
Dualshock PCB -- Using a solderless A-series DualShock hack, I was able to map the contacts I wanted to an 8-screw terminal.
Wiring -- Took apart an old CAT5 networking cable, unraveled the wires, and used that to wire everything up. I also used some 24-gauge solid copper wiring for attaching the PCB terminals to the screw terminal for convenience and better quality.
Cable ties -- Bought a crapload of these on sale at Home Depot, and they're colorful (holidaytime bonus) so they blend in with the easily-as-colorful K'Nex pieces.
Strap -- Taken off my Guitar Hero controller for the time being. It's attached with even more K'Nex!
This project also used NO SOLDER! I'm probably going to regret that one day, but I can't be arsed to do it. I'm terrible at soldering.
The biggest question, how did I manage the pick? This one actually took me a while to figure out. I thought I could go with fashioning one from arcade materials, but in the end I decided to just make it out of more K'Nex after I experimented with the feasibility of the idea. The pick functions like so:
The pick's axle has a small spring attached to the bottom; it is wrapped around the axle for a couple loops and then it's hanging straight downward. On both sides of the axle are two stationary bars. I wrapped a tiny piece of foil around the bars on both sides surrounding the spring. I then tied a ground wire into the spring and attached the "Up" controller wire to both pieces of foil. So when the pick is moved just a little bit from center, the spring contacts either piece of foil, closes the connection, and you play a note. Guitar Freaks is notorious for incredibly fast picking (Jordan has NOTHING on songs like Day Dream) but this switch has no problem keeping up with it. With the up and down motion, the spring MUST break contact with one direction before again closing the switch in the other direction. It's simply not possible for the spring to touch both sides at once.
How does it feel? The best I can say is that it feels like the arcade and then again nothing like the arcade. It functions very well and is spot-on with accuracy; just ask my 95% SS on Yamato Nadeshiko (Basic 'cause I still suck). The buttons are more loose because I believe Konami modifies the arcade buttons with stronger springs. I don't want to compare this controller to the arcade experience because that's a different beast. However, if there was a Guitar Freaks machine that still had the old-school PS1 controller ports, I'd bring this to the arcade in a heartbeat just because it's different and weird.
I have to confess that the tilt sensor is a bit iffy. I think I just gave it the wrong orientation when I attached it to the guitar body, but no worries. I'll have that fixed when I get a chance.
So there you go. If my camera phone didn't suck so damn much I'd record a video... I might do it anyway but it would be a very poor quality.
If you have any other questions, just ask... as long as it's not "Can you build me one?" Unless that question is the followed by "I will pay you money." My free time is precious, thanks.
I may clean this up in the future and take better pictures if I ever get a better camera, too. This project is done but that doesn't mean I can't make this thing look nicer and function better!
I made my own Guitar Freaks controller. Why? 'Cause I could. 
