Can our kicker leg pass the main frame of the robot while it is kicking??? Because it would be very hard to kick the ball in 3 inches. As we know we can let the kicker out for 2 seconds to kick.
It sounds like you answered your own question in the last sentence. What exactly are you asking?
The kicker can extend outside the frame (but not the bumpers) for 2 seconds, then it must be brought back into the frame.
Yes, you can extend up to the bumper perimeter, but can not exceed the bumper perimeter. The 2 seconds is the amount of time the kicker can be between the robot frame perimeter and bumper perimeter. So you can contact the ball in about a six inch area, 3 inches inside the robot, and 3 inches in the horizontal bumper zone. Hope this helps.
See rule <G30a>
Your kicker can extend to the outer edge of the bumper for the sole purpose of interacting with the ball, for 2 seconds.