Section outline

  • Design for Robotics – Chassis and Mounts

    When designing a robot, the chassis serves as the backbone. It holds everything together — motors, sensors, battery, and microcontroller. A well-thought-out chassis design can make a robot easier to assemble, more robust, and easier to maintain or modify.

    • 1. What Is a Robot Chassis?

      A chassis is the physical frame that houses and supports all mechanical and electronic components. In robotics, chassis design can vary widely depending on the type of robot — wheeled, tracked, walking, or aerial.

      2. Key Design Principles

      • Stability: Ensure the center of gravity is low and well-balanced.
      • Accessibility: Allow easy access to wiring and components for testing or repairs.
      • Strength: Reinforce areas that will carry motors or heavy loads.
      • Compactness: Avoid unnecessary bulk while keeping enough room for all components.

      3. Mounting Motors and Sensors

      Different components require different types of mounts:

      • Motors: Use motor brackets or integrate slots into the chassis. Ensure the axle and wheel have room to spin freely.
      • Sensors: Ultrasonic sensors typically go in front, line sensors below or near wheels, and IR sensors depending on behavior detection.
      • Batteries: Should be centrally placed to balance weight and minimize tilting.

      4. CAD Case Study – Recreating a Line-Following Robot Frame

      Let’s take an example of a 2-wheel line-following robot and design its chassis using TinkerCAD or Fusion 360.

      • Base: Rectangle plate (120mm x 80mm x 3mm)
      • Motor Mount Slots: On either side of the back to mount two BO motors
      • Sensor Slots: At the front, for 3 IR sensors placed about 2cm apart
      • Battery Holder: In the middle, with slots for cable routing
      • Microcontroller Space: On top layer or center space for Arduino Nano or Uno

      5. Exporting and Printing

      Once the design is complete:

      1. Group all shapes in CAD software.
      2. Export as STL file.
      3. Slice in Cura/PrusaSlicer with medium infill and layer height of 0.2mm.
      4. Estimated print time: 1.5–2 hours with PLA
      Note: Keep holes slightly larger than required to accommodate 3D printer tolerances. For screw-based assembly, plan hole diameters accordingly (e.g., 3.2mm for M3 screws).