[Alan Anderson]

tomy, I'm not sure you understand the way a "drive system" works. Are you expecting to call "TankDrive" once and have the robot switch to tank drive, and later call "ArcadeDrive" once and have the robot switch to arcade drive? That's not what the functions do.

The Drive() functions take joystick inputs and mix them around to control motors. You have to call one of them at least ten times a second in order to keep your robot moving. You can decide which to use every time through your Teleop() loop, and you can change which one you use whenever you want to.

I agree with the suggestion to use the Z-axis "throttle" as the selection between Arcade and Tank drive.