How to build Bob The Hexapod
18-DoF six-legged walker · Advanced
Build Bob The Hexapod, an MIT-licensed six-legged robot with 18 SG90 servos, a Raspberry Pi Pico, a custom PCB and Bluetooth control from an Android phone.
Many actuators, custom wiring and real tuning work.
Our estimate, part-time
No total is published; the repo lists parts only
MIT
What is Bob The Hexapod?
Bob is a budget hexapod by Papouc that sticks to cheap, easy-to-find parts. Each of the six legs has three SG90 micro servos, so there are 18 joints in total.
A Raspberry Pi Pico runs the inverse kinematics. Most of the electronics live on one custom two-layer PCB, which keeps the wiring tidy, and a homemade 2S Li-ion pack supplies power.
The repo has STEP CAD, Gerbers, a BOM and PlatformIO firmware, all under MIT. You drive it over Bluetooth from an Android app.
Bob The Hexapod specifications
- DoF
- 18 (3 per leg)
- Servos
- SG90 micro servos
- Controller
- Raspberry Pi Pico (RP2040)
- Radio
- HC-05 Bluetooth
- Power
- 2S 18650 pack with XL4015 buck
Figures as published by the project. See Sources below.
Bill of materials
| Part | Qty | Notes |
|---|---|---|
| SG90 micro servo | 18 | |
| Raspberry Pi Pico | 1 | |
| HC-05 Bluetooth module | 1 | |
| Custom 2-layer control PCB + components | 1 | Gerbers and BOM in repo |
| 2S pack (2× Sony VTC5 18650) with BMS | 1 | |
| 3D-printed parts | — | 58 FDM parts; PLA+ upstream |
Where's the full bill of materials?
The full BOM, with exact quantities and vendors, lives in the project's own files. Prices change often, so treat Not published as a ballpark. Start at the project repository.
Tools you'll need
- FDM printer
- Soldering iron
- Small screwdrivers
- PlatformIO
Step-by-step build overview
Electronics & wiring overview
All 18 servo headers are on the custom PCB, which takes power from the 2S pack through the XL4015 step-down stage. The HC-05 connects to a Pico UART.
Software
PlatformIO firmware on the Pico handles gait and inverse kinematics and takes commands over Bluetooth serial.
Tips from the bench
- ☕ SG90s run near their torque limit on a hexapod, so keep the body light.
- ☕ Put a fuse or a protected BMS on the homemade pack.
Bob The Hexapod FAQ
How many servos does Bob use?
Eighteen SG90s, three per leg.
What controls it?
A Raspberry Pi Pico, driven over Bluetooth from an Android phone.
Sources
Written by Bots n' Beans from the project's own documentation. Check the sources for the latest revision before you buy parts.
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