Otto DIY is a small, 3D-printed walking robot with four micro servos (two hips, two ankles) and an Arduino Nano, popular in schools and maker clubs. It walks, dances, plays sounds and avoids obstacles with an ultrasonic sensor, and can be programmed in Arduino or the block-based Otto Blockly.
At a glance
| Parts cost | $60–$70 estimated How Estimated for this page from current retail prices (2026-10-02) of the parts in the project parts list source ↗ Build priced Classic Otto DIY biped (Printables model 31955 parts list): Arduino Nano + I/O shield, 4 micro servos, HC-SR04, passive buzzer, 16340 battery with booster Not included 3D printing, tools, shipping, tax; laptop for programming (assumed owned) |
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| Difficulty | 1/5 Beginner · Four servos, jumper wires and an Arduino, with no soldering and a short print. |
| Build time | About 4 to 5.5 hours of printing for one set of parts (about 100 g of PLA) source ↗ |
| Tools needed | 3D printer (about 100 g PLA, no supports), small Phillips screwdriver, no soldering |
| Motors | 4 micro servos (plastic gears) |
| Controller | Arduino Nano with an I/O shield |
| Sensors | HC-SR04 ultrasonic sensor, passive buzzer |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✓ Video Website with downloadable manuals, Printables STL listings, GitHub Arduino library, build video |
| Activity | Last update 2026-09-07 · 204 GitHub stars · Printables listing with about 29k downloads and 45 makes; Otto Blockly repo updated 2026 |
| Kits | Official kits sold via ottodiy.com and HP Robots, plus many third-party clones |
Licenses
| Design files | CC BY-SA 4.0 (classic Otto DIY STL files on Printables; the newer HP Robots Otto Starter is CC BY-NC-SA) source ↗ |
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| Code | GPL-3.0 source ↗ |
| Documentation | None found (ottodiy.com footer says All Rights Reserved) source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- The new HP Robots Otto Starter is a wheeled robot with continuous-rotation servos and its files are CC BY-NC-SA. The walking biped with the more permissive CC BY-SA license is the classic Otto DIY model. source ↗
- The Otto site itself describes the DIY version as a hobbyist project that is not ideal for young children, with plastic servos, Arduino-IDE-only coding and no Bluetooth app support, and warns that cheap copycat kits often use poor electronics. source ↗
- A fresh Arduino Nano can hold random EEPROM data, which the library read as servo trim values and produced strained leg positions, so calibration should be run on a new board before the first walk. source ↗
- The library targets the Arduino Nano, and ESP32 support remains incomplete because of servo-library limits, so ESP32-based builds need extra work. source ↗
Other bipeds plans
- Open Duck Mini v2 · $400 · difficulty 3/5
- ODRI Bolt biped · $4,700 (2022) · difficulty 5/5