Hardware
Stewy is built from a handful of off-the-shelf parts, a few custom circuit boards and some 3D prints.
Check out the CAD assembly in Onshape here or the Build Guide here to see how it all goes together.
If you have any hardware related questions or ideas, please send them to me using the contact form.
Parts in the shop
Every part below is available in the shop. The Build Guide (PDF) lists the parts used in each assembly step.
| Part | What it is | Price |
|---|---|---|
| Current Sensing Base PCB | Base circuit board with current sensing, so Stewy can feel the force in each servo. | $0.00 – $19.00 |
| Head PCB | Custom circuit board for Stewy's head. Hosts the ESP32-C3 Super Mini, the distance sensor and the joystick. | $0.00 – $11.00 |
| Base PCB | Custom circuit board inside Stewy's base. Routes power and signal from the ESP32-S3-Nano to the six servos. | $0.00 – $19.00 |
| ESP32-S3-Nano | Main microcontroller in Stewy's base. | $12.00 – $17.00 |
| ESP32-C3 Super Mini | Microcontroller in Stewy's head. Reads the distance sensor and the joystick. | $6.00 – $11.00 |
| MG90S Servo Motors (Pack of 7) | Micro servo motors. Stewy uses six of them. | $30.00 |
| Ball Joint Hardware Set (Pack of 7) | Hardware for the ball joint connections on each leg. | $15.00 |
| Clevis Joint (Pack of 7) | Linkage hardware that connects each carbon tube to its servo arm. | $16.00 |
| Carbon Fiber Tubes (Pack of 7) | Upper links for Stewy's six legs. | $14.00 |
| MR83 Miniature Ball Bearings (Pack of 7) | 3 x 8 x 3 mm precision ball bearings. | $12.00 |
| HC-SR04 Ultrasonic Distance Sensor | Ultrasonic distance sensor. Lets Stewy see what is in front of it. | $3.00 |
| KY-023 Joystick Module | Analog joystick for controlling Stewy by hand. | $3.00 |
| JST-XH Cable Set | Cables that connect the head's sensor, joystick and power. | $4.00 |
| Rubber Feet (Pack of 7) | Self-adhesive rubber pads for the bottom of Stewy's base. | $2.00 |
| M3 Hardware Set | Screws, lock nuts and heat-set inserts that fasten Stewy together. | $8.00 |