CROG
Combat Robotics Group
Skills Advanced: CAD (Onshape), Electronics component selection, Soldering, FDM 3D Printing, CNC Mill & Lathe
Objective: Design, fabricate, and iterate on a 1lb and 3lb combat robot to compete in 3-minute competitive matches against other bots in the same weightclass
The 3lb beetleweight, H-SPIN, is a 2-wheel horizontal spinner designed according to the NHRL League ruleset. I worked alongside 2 other teammates while focusing on the electronics selection/fabrication and armor design. H-SPIN is designed with a hard-hitting, piercing weapon, relying on devastating hits over mobility. We use a 680KV 4208 Brushless motor and a 35A ESC to achieve the desired tip speed just under 250 MPH. For the drivetrain, we use 2 brushless drive motors with custom silicone wheels to maximize grip. The wheels are protected by the side armor of the chassis and protrude from both sides of the bot to allow motion if the robot becomes inverted. All of the electronics are contained within a central 3D printed housing, which mounts between the ⅛” 6061-T6 Aluminum top and bottom plates on hexagonal standoffs, which strengthen the frame. There is also a battery plate that can be removed quickly between matches to switch out the 4S 1300mAh battery. This avoids removing the entire top plate for battery swaps.
The build for this robot has been put on hold while the Combat Robotics Group pursues the 1lb plastic weight category, but will be returned to once the 1lb builds are complete.
This bot has been tested in a lightweight PLA form and handles well. We plan to print a full-weight PETG bot and assemble the final version soon!
The outer perimeter of the robot is surrounded by ablative TPU armor, designed to be removed and replaced quickly between matches. Each piece is held on by the hexagonal standoffs and can simply be slid off and replaced when the top plate is removed.
The 1lb plastic antweight, PK FIRE, was designed as a teaching demo bot for the Combat Robotics Group at Olin College. It is designed entirely out of 3D printed parts, except for fasteners and electronics. I owned the design of everything except the weapon, which was designed by another club member. The electronics kit for this bot was also provided as a starter kit to all of the 1lb teams at Olin. The bot features a 2WD Brushed drivebase and an 1100KV 2822 Brushless weapon motor.
