Head

Head
	Side View This is the gearing that we used in the head. The off centered axle in the 40-tooth gear allows the jaw to open and close without having the motor reverse direction. The gear ratio of 5:1 provides enough torque to support the upper jaw.
	Back View The two orange wires connect colored lights to one of the crickets. When Grendel sensed that he had a Dane in his claws, his eyes would turn on or change colors (depending on the variation of the code). Eventually we traded the cricket lights for an LED, this allowed us to free up a port on the cricket.
	Front View From this angle it is easy to see that the 40-tooth gear is attached to the upper jaw and the 24-tooth gear is attached to the lower jaw. This means that Grendel's mouth is attached together only my the black connected at the very back of the long blue legos. It also means that gravity is what is holding the 40-tooth and 24-tooth gears together. As a result, the timing and power of the motor is crucial for keeping the mouth from flinging open, as is the placement of the upper axle. Interestingly, the placement of the upper axle allows the gears to connect together diagonally, which is not a common feature of lego gearing.
This front view also displays a magnet in the bottom of the jaw. The placement of the magnet was intended to help attract Danes into the jaw. Later, a switch was added to the inside of the jaw to allow the motor to know when to stop closing the upper jaw.