Lost Cause Team Blog: Description of Final Machine

Our machine changed quite a bit throughout the design process even though our strategy remained constant. It consists of three main modules: the toggle arm, the scoring arm, and the cart. Each of these has a specific purpose and is designed to meet that purpose in the least complex way possible. We decided that having a simple machine was the best strategy because we anticipated a lot of robots malfunctioning. We felt that we were justified in our strategy when only 11 teams out of 28 even scored during the unopposed seeding round of the competition.

The first module of our machine is the toggle arm. This arm is driven by a planetary gearbox and a worm gear so that it can swing forward with high torque and lock the flipper without being able to be back driven by another robot. This allows both the scoring arm to push balls into the scoring slot and defends against opponent scoring in the slot.

The second module in our robot was the scoring arm. This arm also extends down into the slot and is driven by a planetary gearbox. It is connected to the motor by a gear train and is secured to its axle by spring pins. In order to ensure that we could keep this arm in the starting zone every time, we attached one end of a Kevlar thread to the end of the arm and wedged the other end under one of the cart’s wheels. The sole purpose of this was to hold the arm up in the air until we could engage the motor to move it.

The final module of our concept is a cart that drives on the top of the table. This cart is used both for offense to score balls in the opposite cone and for defense to stop the opposition from scoring in our cone. As with the other two modules, we worked at making this as simple as possible. This paid off in the competition where many of the carts either were too heavy or complex to move or got stuck because they did not have enough time to practice driving. Our cart base is made of acrylic. On this we mounted the double gearbox, the axles, and an “antenna” that holds up the wiring to the slot module to keep it from tangling. On the front the cart has claws to catch balls and on the back has a wider section that can be used to cover the cone. We used the provided wheels but added rubber bands to the drive wheels to increase traction but left them off non-drive wheels to still allow easy turning.