modular robot 3d model

Design a physically buildable, modular companion robot chassis that can be upgraded from a prototype into a final version. Known electronics: - ESP32 WROOM-32 Type-C development board - 0.96-inch SSD1306 I2C OLED display used as the robot's face - HC-SR04 ultrasonic distance sensor - TB6612FNG dual motor driver - Single-cell 3.7V 3500mAh LiPo battery, 0.5C - Two small geared DC motors with two drive wheels - One caster wheel Mechanical requirements: - Compact desktop-sized robot - Approximately 18 cm wide × 14 cm deep × 20 cm tall - Two-level internal chassis - Rounded, friendly exterior - Removable panels secured with screws - Dedicated mounting points for every current electronic component - Easy access to the battery and electronics - Internal cable-management channels - Ventilation openings - Strong enough for repeated movement Future upgrade provisions: - Reserved mounting location for a camera - Microphone opening - Speaker chamber - Space for additional sensors - Mounting