SigmaC@T 2007 represents the beginning of a new design world for Team 108. This year’s design builds on aspects of the very best of Team 108’s robots, for instance the 2005 Curie Division Champion and the 2003 Florida Regional Champion robots both are incorporated into the design. Modularity is once again the basis to our design strategy. For the past two seasons, Team 108 has been designing modular drive trains, where the entire wheel assembly can be removed at a moments notice. This was to cut down on time between maintenance and repairs at competition, and has more than once in the past been a winning element of our design. This year’s robot has a 6 wheel drive system, using 6inch wheels with “Rough Top” on them, we can compete in most pushing matches. The center wheel is lowered only 1/8th of an inch to allow for ease of turning. We are using the BaneBot KOP transmissions.

The arm this year has 4 moving parts, and can extend to nearly 14 feet vertically. The base of the arm is mounted to the back of the frame of the robot, where it telescopes from. The telescoping mechanism is very similar to a design we implemented in 2004 that could lift our entire robot during the final seconds of FIRST Frenzy: Raising The Bar. The telescoping section is powered by a Globe motor and a 4:1 reduction to a rack and pinion gear system to make the linear transfer.

The shoulder this year is of particular importance, as it is the first time Team 108 has implemented a worm-gear drive system. Using a Globe motor mounted inside the telescoping part of the arm, and a 30:1 gear ratio using a 12 pitch worm gear, we were able to effectively and robustly lift our arm around the entire robot. The wrist is powered by a Denso Window motor mounted near the shoulder with a long strand of #25 chain transferring the power. The sprocket reduction is approximately 1:3.25, this allows us to have a high torque wrist, while still allowing for a fast but controllable joint. The gripper mounted at the end of the wrist is opened by a lead screw and closed by spring-loaded hinges. The tension in the hinges can be adjusted for each side of the gripper. The gripper is very powerful and has yet to drop a ringer.

The electrical board this year is a true work of art. This is another aspect of robot design that Team 108 prides itself in. We design our electrical board so that it is entirely modular. Using banana-connectors for all the motors, and running all the power and PWM cables under the board through holes drilled in it, the board stays clean, open, and accessible. Accessibility is key in a successful design, and with 4 thumb screws, the entire board can be removed if an issue is not already accessible.