This offseason our team focused on an offseason competition called BunnyBots! This thread will recap our BunnyBots experience.
Cad links: Main | Drivetrain | Wrist | Shooter/Indexer | Intake
Code link: Bunnybots 2023 GitHub
What is BunnyBots, and what is this year’s game?
BunnyBots is an off-season competition put on by team 1540, The Flaming Chickens, from Portland, Oregon. It uses a different set of rules than an FRC game but is often similar to FRC games.
This year’s game involves picking up stuffed bunnies from standard FRC totes in the middle of the field and scoring them in “home zones” while also picking up 2017 wiffle balls from loading zones and shooting them at targets (5-gallon buckets) mounted above each robot. Stealing bunnies from the opposing alliance’s home zone is also allowed.
Our team uses BunnyBots as a way to train new members and prepare returning members for the upcoming build season.
Our Approach to the Game
We decided on a robot with a wide, wristed intake to pick up bunnies from totes and the ground, as well as a ball indexer and shooter. We opted not to pick up balls from the ground to save on complexity, loading only from the loading zone.
Design
Wrist
Our wrist uses live-axle REV maxspline, which we’ve found offers a great balance of rigidity and mounting flexibility. It rotates inside two 1-⅜” brass bushings from McMaster-carr.
Bunny Intake
Our intake is 23” wide, with two rollers that can move relative to each other on elastics to allow more flexibility in intaking different-sized bunnies.
Ball Indexer
Our indexer has an opening at the back of the robot where our human player will load the balls. From there, flat orange belt brings the ball up to a counter-rotating wheel just under the shooter.
Ball Shooter
Our shooter is located as high as possible with a very flat shot angle. This allows us to hit the buckets at varying ranges without needing an adjustable hood. We 3D printed our shooter hood and attached swerve tread for increased grip, which has been working great.
Major Takeaways
Effective Training and Member Retention
Our lackluster new member retention from previous years’ fall training left us with something to improve this year. To get more involvement from newer members, we introduced BunnyBots soon after the school year began and incorporated the BunnyBots build process into our training modules. This has allowed new members to gain hands-on experience as quickly as possible and has given them something to be excited about early in the year. Overall, this led to us having a much better member retention and a more complete training process for new members. This is the most new member involvement we have had in team history, so we are likely to continue with an early introduction of our off-season build in future years.
Assembly Speed Improvements
After having difficulty meeting assembly deadlines last build season, we wanted to test some organizational improvements during BunnyBots.
Taking inspiration from other teams, we implemented “kitting” for every subsystem on the robot, setting aside storage containers to collect all the parts necessary to build the subsystem before we started assembling it. We coupled this with “kitting documents” created by our CAD team with tables that listed parts and specifications. Additionally, we made a “cut list” that listed all the parts that needed to be cut to length for the robot (shafts, tube, etc). Parts that needed to be cut to length were listed both in their subsystem’s kitting document and the cut list.
These changes allowed us to assemble the robot in about half as many meeting hours as it took us for our Charged Up robot, including the time kitting took. We were able to much more effectively get tasks done in parallel with all of the parts ready, which was huge for both new member involvement and build efficiency.
