Our robot, Blue Scorpion, for 2011’s competition Logomotion, is designed to be able to pick up tubes and hang them on the scoring rack efficiently, without losing balance or speed. The wood in the robot is African marine grade plywood.
The chassis is the main body of the robot. It is made with welded aluminum square tubing, with Toughbox Minis gearboxes and Plaction wheels. The robot was intentionally geared for higher torque and lower speed so that the robot will have more “pushing” power.
The robot uses a drop centered wheel (where the middle wheel is dropped lower than the other wheels), which means that only 4 of the 6 wheels are touching at any one point. This allows the robot to be both fast and maneuverable as it reduces sideways friction on the wheels.
The first 15 seconds of a match is the autonomous period. Drivers are not allowed to control the robot while the robot attempts to hang the yellow “ubertube.” Our robot is programmed to track the line to the rack and hang an ubertube on the top row.
The wooden arm is one of the most visible aspects of our robot. Made of spruce and lightweight marine plywood, it functions much like a human arm would; the arm features three joints, a wrist, and a gripper mechanism. There are two belts that allow the first and second joints to move smoothly, a wrist, and a roller mechanism to pick up tubes.
To reduce strain on the window motors powering the “forearm” of the robot, we employed gas lift struts (commonly found on hatchbacks) to preload the “forearm.” The “arm” of the robot is preloaded with bungee cords.
The minibot is deployed from the chassis during the last ten seconds of the match to earn bonus points. It is extremely speedy, as it can climb the pole in 1.5 seconds, and can be deployed in one quarter of a second.
The main structure of our minibot is PVC piping, which holds the Tetrix motors and battery pack in place. When the minibot hits the top of the pole, it flicks off a light switch that shorts the TETRIX motors, which provides a braking action to allowed for a controlled descent.