Fire and Fetch
For my project this year, I decided to continue my project from last year to add a new launcher feature. Last year, I created a robot that picked up tennis balls. With this, I already have a functioning robot with a front attachment that collects the balls. Initially, I wanted to make an arm that could grip the ball and throw it, but I didn’t have enough time to take on this challenging design, so after some research, I went with my current design because it was something I could accomplish in the allotted time frame. For the wooden launcher attachment, attached to the robot at an angle with two motors, I started off at 400 rpm, then 600 rpm, and finally ended with 1000 rpm, as this was the perfect speed that launched the balls at the perfect speed and angle. I put the motors on opposite sides to keep the rotation the same; otherwise, I would have to switch polarity on the motors to keep the movements aligned. As for the bucket, the design took two tries to accomplish the wooden planks because I had to align the holes with one another to allow a single ball to drop at a time. I had to adjust the sizing of the holes, as well as the bucket hole, because I started with 2 inches and then had to increase to 3 inches to allow the balls to exit the bucket. The bucket motor is a high-torque, low-velocity motor that makes it spin slowly, making it capable of spinning heavy items at a low speed. In addition, the broom is inside the bucket to guide the balls one at a time into the hole, where they would drop down the ramp and into the launcher. For the launcher wheels, I initially started with RC car wheels that didn’t end up working out because the wheels were plastic, so there was no grip to propel the balls. Then, after some research, I discovered flex wheels on a robotics website, which were a success because they had the texture of a #2 pencil, which was enough to grip the balls and propel them outwards.
