State Of The Art Defense
Leave the guard dog inside because this guy is on the forefront of meeting all of your surveillance and defensive needs.  Kids will have a blast with this high-powered, ball-launching robot that can take down the baddies before they get to close.
Another cool ability is that it can spin on a dime to give 360° of protection.  The Ultrasonic Sensor up front can spot anything that moves and then launch into a program that will flash a warning light before launching a ball.
How does it work?
Three motors work together to keep the Tower Defense Bot running smoothly. The lowest motor on the tower works to rotate the base. This keeps the bot on a swivel and guards us against sneak attacks. The middle motor raises and lowers the ball launcher. Intruders beware! When that launcher is raised, you better stand clear or face the tower’s wrath. The top motor powers the mechanism that fires the ball launcher and teams up with the Ultrasonic Sensor in a really cool way: If the Ultrasonic Sensor detects an enemy coming in close, it triggers the top motor to fire!
Pictures
