Disclaimer: I would NEVER EVER recommend that anyone use a motorized mountainboard with straps. If you're wondering why I am saying this, it's because it was only after riding it for a while that I realized why everyone feared so much for my safety. You'd have to be insane to want to build this and ride it! I felt comfortable knowing I have years of experience in skateboarding, snowboarding, skimboarding, and surfing to really give me control of the board, but I never underestimated what I built nor did I ever forget about Murphy's Law. Heck, even all my board experience wasn't enough for the 4 second delay that came from the PlayStation 2 controller when I was trying to stop the board. I ended up cleaning the pavement a few feet with my leg, as you can see in the picture below. In anything you do, always be careful, be willing to accept the consequences for whatever you do and when something happens, you have no one to blame but yourself. So let me repeat this: I am not and will never be liable for anything that happens to you.
Now that we have that out of the way, let my project show you that when you follow your dreams, ignore the naysayers, and push yourself to your full potential, you achieve things that you had never imagined. People far too often underestimate their own strengths and skills, and many brilliant ideas end up just being an idea and nothing more. I want my project to show everyone that they can make anything a reality if they go for it. When I first started the project, I didn't really know about motors and I had to refresh my memory on some of the topics I learned in my classes. If you have the motivation, you can learn everything about a certain topic, as well as master it, and make it your own. Don't ever let anyone tell you that you can't do something if you truly believe in what you are shooting for. All that being said, I'll leave you with what renowned Irish playwright George Bernard Shaw once said: "You see things; and you say, 'Why?' But I dream things that never were; and I say, 'Why not?'"
By the way, here is a link to a video of my board in action just in case you're interested: http://www.youtube.com/watch?v=686oJ7bNFIU
Step 1: Materials
Brushless Outrunner Motor
-RimFire 1.2: http://www.electrifly.com/motors/gpmg4505.html
Brushless Motor Controller
+Can't find the exact one that I used, but I'm pretty sure this should do
Lithium Iron Phosphate Battery
SparkFun Flex Sensors
SparkFun NRF2401A Transceiver
I bought my board on eBay, and I think it's an MBX mountainboard. The rest of the materials were either purchased at Home Depot (thick gauge wires), made from the ECE Machine Shop (casing for my battery, casing for the motor, and gears), or given to me from the ECE Service Shop (buttons, small wires, LEDs, op-amp). Some of the board was also built in the ECE Machine Shop.