Aero Hand Open

Aero Hand Open is an open-source, tendon-driven robotic hand designed by TetherIA for dexterous manipulation research. Unlike expensive proprietary solutions, this hand focuses on simplicity, reliability, and accessibility — fully 3D-printed structure with off-the-shelf electronic components.

Key Specs: 7 DoF | 16 joints | 5 fingers | 389g | ESP32-S3 controller | 7× Feetech HLS3606M servos

Attribution: TetherIA Inc. — https://github.com/TetherIA/aero-hand-open
License: Design files (CAD/STL/BOM/docs) — CC BY-NC-SA 4.0 | Software (firmware/SDK) — Apache-2.0
Source: https://github.com/TetherIA/aero-hand-open
Docs: https://docs.tetheria.ai | Shop: https://shop.tetheria.ai

Printing

This is a single left hand (all parts are left_ prefixed; the upstream repo also publishes a mirrored right hand under right_ prefixes if you need the opposite hand).

Structural / palm (1 each):

• left_base_link — palm/chassis
• left_t_link — thumb carpometacarpal mount

Five finger chains. Each of the four fingers (index, middle, ring, pinky) is a four-link chain; the thumb is its own four-link chain:

• Index: left_index_proximal / _middle / _distal / _tip
• Middle: left_middle_proximal / _middle / _distal / _tip
• Ring: left_ring_proximal / _middle / _distal / _tip
• Pinky: left_pinky_proximal / _middle / _distal / _tip
• Thumb: left_thumb_mcp / _proximal / _distal / _tip

Mount adapters (pick the one that matches your wrist/base — optional):

• 135degrees_adapter — for a 135° angled mount
• threaded_mount_adapter — for a threaded base mount

Print in PLA, 0.2 mm layer height, tree supports on the build plate only. Per the BOM, several small hardware items are not separate STLs: the 6× cable spools and the silicone finger pads are produced by other means (spools are integral / cast pads use Ecoflex 00-30 in a mold). Buy undersized 2x10 pins — standard 2x10 pins are too tight for the 2x5x2.5 mm bearings and cause joint stiffness. Route the tendons before final assembly of each finger module; retrofitting cables through assembled joints is extremely difficult.

The full set is 24 STL files (22 hand parts + 2 optional mount adapters), driven by 7× Feetech HLS3606M servos.