Hexapod Nougat

Hexapod Nougat is a six-legged, WiFi-enabled walking robot with 18 degrees of freedom — the second generation of the RookiDroid hexapod, and the one where the gait finally came good. Torque alone wasn't the whole answer: dedicated PCA9685 PWM drivers and a power stage sized for all 18 servos at once turned the strength of its 21G digital servos into smooth, steady walking. Print it, bolt it together, connect to its WiFi, and drive it from your phone.

What's in the print profile

• All printable parts for the Nougat chassis: body, joints, legs, feet and servo mounts

• STLs for any desktop FDM printer

• PLA or PETG — no exotic materials. TPU is recommended for the foot tips only

• 0.2 mm layers, 20–30% infill, supports on some parts

Key specs

Wireless from day one

Nougat runs the same open-source ESP32 firmware as the rest of the family:

• 19 built-in motions — standby, walking at six headings, fast walk, turns in place, a climbing gait, body pitch / roll / yaw and twist

• Android app for point-and-go control, or a documented binary UDP protocol if you'd rather write your own client

• Real-time pose streaming — drive all 18 joints live from a computer at 50 Hz, with per-joint slew limiting and a 1-second failsafe. Hexapod Link is a free desktop app that does exactly that

• Browser calibration — set every servo offset live at http://192.168.4.1; values persist in EEPROM across power cycles

• OTA updates — upload new firmware over WiFi, no USB cable needed

Designed to last

Every structural decision in Nougat was deliberate:

• Layer orientation — print layers align with load directions, distributing stress along their length rather than across them to prevent delamination under walking forces

• Reinforced joints — leg segments and servo mounts spread loads and minimise stress concentrations

• Circular frame — optimises the weight-to-rigidity ratio and distributes servo loads evenly across all six legs

• Modular assembly — interlocking parts reduce adhesive dependency; repairs and upgrades need no specialised tools

• Material flexibility — the geometry performs reliably in standard PLA or PETG under repeated dynamic stress

What else you'll need

The printed parts are one half of the robot. To get it walking:

• 18 × 21G digital servos — buy them from one batch so they behave consistently

• An ESP32 dev board and a controller board — Nougat shares the Mochi board (pre-assembled, or roll your own)

• 2 × protected 18650 cells, a 2-cell holder and an SPST toggle switch

• Hardware: 36 × M2×6 mm hex socket screws, 180 × M2×12 mm countersunk screws, 216 × M2 nuts, 18 × M4×6 mm pins, 18 × MR74-2RS bearings

• Tools: a hex key set and a small screwdriver. No soldering required with the pre-assembled board

One tip before you start

Do NOT tighten the servo horn screws during assembly. Leave them loose and tighten them during calibration, once each servo is sitting at its true neutral position. It saves a lot of backtracking.

Full build guide

Everything — printing, assembly, wiring, firmware and calibration — in one step-by-step guide:

• 📖 Build Your Own Nougat

• 💻 Firmware source — GPL v3, free

• 📱 Android app

Nougat has two siblings: Mochi, the compact MG92B redesign that came next, and Macaroon, the 25 kg heavyweight. One firmware runs all three.

Its own chassis, built for torque. Print it and make it walk.

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