I am also a Robocup Junior competitor,
My High school's robotic club is working on designing a robot for the Robocup Junior soccer competitions http://rcj.robocup.org/soccer.html
But this is our first year, so we have a lot of questions, and I'm confident you guys will be able to help.
you came to the right place
First off, is there any place where we can buy sheets of aluminum or carbon fiber, which will serve as chassis for our robot, or would we have to buy it and cut it?
Is there an easier way?
Well unless you want to build a lego chassis, then there isn't really an easier way
you have to buy the aluminum, carbon-fiber yourself, and then cut it.
I know that these guys sell carbon-fiber:http://www.robotmarketplace.com/store.html
but otherwise I recommend using plastics, or Plexiglas, which is much better/ lighter.
Also, is anyone familiar with the kicker and dribbler system robots use to capture and kick the ball?
That's our biggest hurdle so far :\
the best type of kicker is a solenoid, or if you want a REALLY good kick, look into pneumatic systems.
the dribbler is just one or two smaller motors with a rubber wheel attached to them, nothing fancy.
On the other hand, doing some research, we've noticed teams using a pair of photo-resistors//photo-transitors that signal when the ball is captured in the dribbling system.
Does anyone know, how that actually works?
Thanks guys, that's all for now!!
yes that is a very common way to see if the ball is captured, it basically works as a tripwire.
when the photo-transistor can't see the Ir light from the emitter then you know there is something in the way,
(not always the ball)
but also remember you need to use photo transistors for ball sensing,
i recommend just using 2 tactical switches, or any touch sensitive sensor, and putting it in the ball capture area
that way you will have a better idea if the ball is there.