Skip to content
ShopCommunitySign in
Advanced build

How to build ORCA Hand

17-DoF dexterous robot hand · Advanced

Build the ORCA Hand: a 17-DoF tendon-driven hand with tactile fingertips from ETH Zurich, assembled in under 8 hours for under 2,000 CHF in materials.

Start the buildProject files
Difficulty
Advanced

Many actuators, custom wiring and real tuning work.

Build time
Under 8 hours of assembly, per the paper

Based on the project's guide, part-time

Parts cost
$2,431

Below 2,000 CHF in materials per the paper; the legacy v1 Dynamixel BOM totals about $2,431 including shipping

Degrees of freedom
17

CC-BY-4.0

What is ORCA Hand?

ORCA (Open-source, Reliable, Cost-effective, Anthropomorphic) comes from Robert Katzschmann's Soft Robotics Lab at ETH Zurich and was accepted to IROS 2025. It's a 17-DoF tendon-driven hand with tactile sensors in the fingertips.

The design leans hard on reliability. Joints are built to pop out under overload rather than break and snap back in, and the hand auto-calibrates and has a built-in tendon tensioning system. The team ran it for more than 10,000 cycles, about 20 hours, without a hardware failure.

The paper reports full assembly in under eight hours for a material cost below 2,000 CHF. The project now lives under ORCA Dexterity, with both Dynamixel and Feetech motor options.

ORCA Hand specifications

DoF
17 (16 finger + 1 wrist)
Actuation
Tendons; Dynamixel XC330 or Feetech motors
Sensing
Fingertip tactile sensors
Endurance
>10,000 cycles (≈20 h) tested
License
CC BY 4.0 hardware, MIT code

Figures as published by the project. See Sources below.

Bill of materials

PartQtyNotes
Dynamixel XC330-T288-T16Plus one larger wrist motor; Feetech set also supported
Printed forearm, tower, carpals, palm and fingers—
Silicone skins cast from printed molds—
Tendon line and PTFE tubing—
Thin-film force sensors for fingertips5
Where's the full bill of materials?

The full BOM, with exact quantities and vendors, lives in the project's own files. Prices change often, so treat $2,431 as a ballpark from the project. Start at the project repository.

Tools you'll need

  • FDM printer
  • Silicone casting supplies
  • Hex keys
  • Soldering iron

Step-by-step build overview

Electronics & wiring overview

Servos share one serial bus to the PC. On Linux add your user to the dialout group, or the motors won't be detected.

DC power supplypower sourceLaptop / PChigh-level controlEncoderssensingArduino boardreal-time controllerServo bus adapterdrivers / busDynamixel XC330 servos17 joints / motors
PowerData / commandsSensor feedbackOverview only. Follow the project's own schematic for pinouts and voltages.

Software

MuJoCoURDF model

orca_core is the Python controller (install with uv or pip); orca_ui offers a friendlier setup and tuning interface. The team demonstrates teleoperation, imitation learning and zero-shot sim-to-real RL.

Tips from the bench

  • ☕ Let the popping joints do their job; reseat a dislocated finger instead of forcing it.
  • ☕ Re-run the tensioning script after any tendon work.

ORCA Hand FAQ

How much does the ORCA Hand cost?

The paper puts material cost below 2,000 CHF.

How long does it take to assemble?

Under eight hours, according to the authors.

Does it have touch sensing?

Yes, the fingertips carry tactile sensors.

Sources

Written by Bots n' Beans from the project's own documentation. Check the sources for the latest revision before you buy parts.

Related builds

Robot deals

All deals →
  • Everblog AI fridge calendar

    Deal · Everblog

    10% off

    Get deal
  • CircuitMess DIY robot kits

    Shop · CircuitMess

    DIY robot kits

    Robot and gadget kits you build yourself.

    Shop
  • GRABO Cordless vacuum lifter

    Shop · GRABO

    Cordless vacuum lifter

    GRABO Pro Brushless: the original cordless vacuum lifter for pavers, stone, glass and panels.

    Shop

Like what we do? Buying through these links supports Bots n' Beans. We earn a commission at no extra cost to you. Thank you!