Motor Mounting

Mechanical pic

Stepper Motors

The x-axis and y-axis of the gantry are powered by NEMA-17 stepper motors. They supply 28oz*in of torque in order to rotate the threaded rods and move the gantry cars. The z-axis of our gantry is powered by a HK15138 standard analog servo motor. The motor powers the rack and pinion and moves the gripper up and down in order to pick up and move the checker pieces.

3 Axis Operation

Aluminum Gantry

The gantry frame is a 28”x24”x20” cube made entirely out of 6061 aluminum. Two NEMA-17 stepper motors are bolted onto the frame in order to turn two ½”-10 ACME threaded rods that drive the gantry cars. The gantry also has a mount above it that is designed to hold the Arduino, Raspberry Pi, and Raspberry Pi Camera above the center of the board in order to allow for full computer vision of the board.

Mechanics pic

Universal Gripper

Mechanical pic

Coffee Balloon

We used a universal gripper to pick up the checker pieces. The balloon for the gripper is filled with coffee grounds. When the gripper is pressed down on top of a checker piece, the coffee grounds form around it. The air is then sucked out of the balloon by a vacuum pump forcing the coffee grounds to tighten around the checker piece. The servo motor then lifts the checker piece off the board so it can be moved to a new location.