Mechanisms before code
Tendon path length and joint friction show up in your hands before you touch the IDE. Optional microcontroller extras are secondary to the kinematics.
Projects / Animatronic Hand
Animatronic Hand
Flagship pack — a complete animatronics apprenticeship in one build. Laser-cut 3mm birch plywood, M2/M3 revolute joints, Spectra tendons, five SG90s, wiring, PWM, and calibration. Finish with a keepable desk / club machine, not a throwaway craft.
$29 Flagship pack
Digital guide + SVG/DXF cut files + BOM + code · Parts sourced separately · Ages 10+ with adult help
Digits5 independent
Servos5× SG90
Structure3mm birch plywood
ControllerArduino / ESP32
Build time4–8 hours
Skill levelIntermediate
Pack contents
- Full apprenticeship path: structure → joints → tendons/servos → wiring → PWM → calibration
- Illustrated build guide + SVG/DXF cut files (palm, phalanges, forearm tray)
- Verified BOM with honest plywood hardware costs (5× SG90)
- First-principles lessons: DOF, levers, antagonistic tendons, PWM
- Arduino sketch: sweep, wave sequence, optional potentiometer control
- Wiring diagrams, troubleshooting, extension paths (antagonists, sensors)
Typical hardware cost
Marketing matches the build: laser-cut birch plywood, machine-screw hinges, Spectra tendons, and five SG90 micro servos—hobby electronics you can source, not a factory robot arm.
- ~$45–90 in parts for the full plywood hand (makerspace cut toward the low end; mail-order laser + buying a controller toward the high end)
- Optional PETG-printed structure if your club has a printer; plywood is the default
- Expect more than a craft kit — this is a lasting demo
The $29 pack is the digital guide + cut files + BOM + lessons + code. Hardware is sourced separately — see Where to get kit materials (affiliate partnerships pending).
BOM you can verify
Five SG90s, M2/M3 revolute joints, Spectra tendons, birch plywood (or PETG), Arduino or ESP32. Common hobby parts—no proprietary lock-in. Sourcing guide →
Built to extend
Finish the base five-digit hand, then add antagonist extensors, joint sensors, or a mirrored second hand. The pack ends where your experiments begin.
Learning outcomes
- Map degrees of freedom across five digits (thumb + index + middle + ring + pinky)
- Laser-cut and hinge plywood finger segments; mount and center five micro servos
- Route independent flexor tendons and manage slack, stretch, and binding
- Drive servo angles with PWM (~500–2500 µs) via the standard Servo library
- Calibrate open/curl limits; distinguish open-loop commands from closed-loop sensing
- Reason about torque, mechanical advantage, and underactuated multi-joint curl