by United Robotics
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Build Instructions (Version 2)

Before you start

  • Skill level: beginner-friendly if you can 3D print + use a screwdriver.
  • Time: first build usually takes a weekend.
  • Goal: assemble + run the first motion test safely.

Rule #1: don’t force-fit parts. If it doesn’t fit, trim/sand gently.

1) Parts you’ll need (BOM)

Grab these parts before you start the build. Equivalent alternatives are fine as long as the specs match.

Part Qty Buy link
ST3020 serial bus servos (arm servos)
8 total — 4 per arm
 x8
Waveshare →
ST3215-HS 30kg serial bus servos (neck + torso)
3 total — 2 neck, 1 torso
 x3
Waveshare →
VSPRO high-speed camera (USB)
Used for tracking + higher FPS recording.
 x1
eBay →
7.5V 10A Power Supply Adapter
Stable 7.5V supply with current headroom.
 x1
Amazon →
M3 countersunk machine screws (assortment)
Self-tap into printed holes (~2.8mm). No nut traps needed.
 x1 kit
Amazon →
20 AWG electrical wire
For power distribution runs.
 x1
Amazon →

Tip: buy the parts first, then do servo centering before assembly.

2) Setup — Set Servo ID's and center your servos first (do this BEFORE printing/assembly)

Mandatory. Center and ID servos before you install them.

Nova Desktop servo ID map (neck, arms, torso)

If a horn can’t be perfectly straight because of spline steps: choose the closest, then correct later.

3) Servo driver setup (ESP32) — upload code + Wi-Fi details

Configure your ESP32 boards early so the rest of the build is smooth.

  1. Open the ESP32 code in the Arduino IDE
  2. Install the SCServo library (FT&WS) in Arduino IDE
    Go to Sketch → Include Library → Manage Libraries…
    Search for SCServo and install “SCServo by FT&WS”.
    Important: don’t add the library to the sketch manually — once installed via Library Manager, Arduino will include it automatically.
  3. Set your Wi-Fi SSID + password
  4. Set your PC/laptop IP address for UDP (Windows: ipconfig → IPv4)
  5. Upload sketches to each ESP32 (arms + torso/neck)
  6. Confirm Wi-Fi status LED (white dot flashes when connected)

Tip: keep rear door open during setup so you can access boards.

4) Build Order (Recommended Sequence)

  1. Print base
  2. Print torso
  3. Mount servo drivers on rear door (arm driver top, torso/neck bottom)
  4. Attach rear door (leave open) until all servo cables are connected
  5. Print + assemble arms and neck, then slot into torso and connect

5) Arm Build

  1. Print arm parts and test-fit
  2. Install centered servos building outward (shoulder → forearm)
  3. Route cables as you go (avoid pinch points)
  4. Mount arms into torso, then plug into arm driver

6) Neck Build

  1. Print neck parts
  2. Assemble with centered servos
  3. Route cables with slack
  4. Mount neck into torso, then plug into torso/neck driver

7) Camera fitment (VSPRO)

Fit the camera mount and route USB with slack for full motion.

  1. Print camera brackets and clean supports
  2. Mount camera securely
  3. Route USB cable to avoid snagging during motion

8) Next: Software installation

Move onto the software installation guide.