Hexapod Macaroon

Hexapod Macaroon is the biggest and strongest of the RookiDroid hexapods: six legs, 18 degrees of freedom, eighteen 25 kg digital servos, and a four-cell 18650 pack to feed them. Built on everything learned across three earlier generations, with the leg geometry and body opened up to match the hardware. Drive it from your phone or laptop over its own WiFi access point, calibrate it in a browser, and push firmware over the air.

What's in the print profile

• All printable parts for the Macaroon chassis: body, joints, legs, feet, servo mounts — plus an optional fence

• 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

Built for torque

Macaroon is the heavy-duty member of the family, and the electronics are sized to match:

• Servos driven directly — the Macaroon controller board feeds them straight from the 2S pack, so they get the full 8.4 V at full charge, with bulk capacitors absorbing the current spikes

• Four cells in 2S2P — twice the capacity of the two-cell builds, for longer sessions between charges

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

• 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 Macaroon 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 × 25 kg servos rated for 8.4 V — buy them from one batch so they behave consistently

• An ESP32 dev board and a Macaroon controller board (pre-assembled, or roll your own)

• 4 × protected 18650 cells, a 2S2P holder and a 12 mm 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

Safety

Protected cells only, charged with a proper 2S charger. Check battery polarity twice before the first power-up — reversed polarity will destroy the controller board. Eighteen 25 kg servos have enough torque to pinch hard, so keep fingers clear of the joints when powered, and support the robot on first power-on: it runs its stand-up sequence automatically as soon as a client joins its WiFi.

And do NOT tighten the servo horn screws during assembly — leave them loose and tighten them during calibration, once each servo is at its true neutral position.

Full build guide

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

• 📖 Build Your Own Macaroon

• 💻 Firmware source — GPL v3, free

• 📱 Android app

Want something smaller? Mochi (MG92B micro servos) and Nougat (21G servos) are the compact members of the family. One firmware runs all three.

The biggest of the three. Print it and make it walk.