GEX Series

Ultra-low-cost fully-actuated dexterous hand and teleoperation system

GEX Series

Home > Hardware > Hands > GEX


Overview

GEX is an ultra-low-cost dexterous manipulation system developed with the goal of Democratizing Dexterity. It provides a closed-loop teleoperation framework consisting of the GX11 robot hand and EX12 exoskeleton glove.

ItemGX11 HandEX12 Glove
DoF1112
Price~$600-
Assembly TimeUnder 4 hours-
Number of Fingers3 (thumb, index, middle)3
Cost Comparison1/125 of Shadow Hand, 1/20 of Allegro (per paper)-

GX11 Hand Detailed Specs

Mechanical

ItemSpec
DoF ConfigurationThumb 3 DoF + Index 4 DoF + Middle 4 DoF
MaterialABS plastic (3D printed)
Drive MethodFully-Actuated
Design Base3-finger design based on LEAP Hand

Actuators

ItemSpec
MotorDynamixel XL330-M288-T
Torque0.53Nm (rated)
Gear Ratio288:1
Weight18g / actuator
Size24.5 x 33 x 25 mm

Sensing and Control

ItemSpec
EncoderAS5601 (12-bit absolute position)
Position Resolution0.088°
CommunicationTTL Multidrop Bus (up to 1Mbps)
Power5V DC
Control ModesCurrent/velocity/position control
ProcessorARM Cortex-M0+

Key Significance

Democratizing Dexterity

The greatest significance of the GEX project is dramatically lowering the barrier to entry for dexterous manipulation research.

Existing problems:

  • Shadow Hand ($75K+): Excellent performance but unaffordable for most labs
  • Allegro Hand ($12K+): Mid-range price but still high initial cost
  • Tendon-driven systems: Difficult maintenance, cable wear issues

GEX solutions:

  • Under $600 manufacturing cost enables anyone to research dexterous hands
  • Fully-actuated approach eliminates tendon system complexity
  • 3D print based for immediate replication and repair
  • Under 4 hours assembly for rapid deployment

Accelerating VLA Research

Proliferation of affordable dexterous hands directly impacts VLA (Vision-Language-Action) research:

  1. Expanded Data Collection: More labs can generate dexterous manipulation data
  2. Teleoperation Accessibility: High-quality demonstration data acquisition through EX12 glove integration
  3. Distributed Research: Inexpensive replication of same platform promotes multi-site research

Design Philosophy

Why 3 Fingers?

Reasons for adopting 3-finger structure departing from LEAP Hand’s 5-finger design:

  • Maximum Flexibility: Most manipulation tasks achievable with thumb, index, and middle fingers only
  • Human Hand Mimicry: Reproduces core human grip patterns (precision grip, power grip)
  • Reduced Complexity: Weight and size optimization, simplified control
  • Cost Reduction: Reduced BOM cost through fewer actuators

Fully-Actuated vs Tendon-Driven

CharacteristicFully-Actuated (GEX)Tendon-Driven (Shadow)
State ObservabilityFully observableErrors from cable stretch
Kinematics ModelingAccurateNonlinear elements exist
MaintenanceSimpleCable replacement required
Force TransmissionDirectFriction losses
CompactnessRelatively largerCan be compact

Cost Analysis

BOM (Bill of Materials) Estimate

Costs below are estimates based on general market prices; actual costs may vary by vendor/quantity

ItemQuantityUnit Price (est.)Subtotal
Dynamixel XL330-M288-T11~$50~$550
3D Printed Parts (ABS)1 set~$20~$20
AS5601 EncoderBuilt-in--
Wiring/Connectors1 set~$15~$15
Other Hardware-~$15~$15
Total~$600

Not included: Controller, power supply, assembly tools

Cost Comparison with Other Products

Paper states 1/125 cost of Shadow Hand, 1/20 of Allegro

ProductPrice (per paper)Cost Ratio
Shadow Hand$75,000+125x
Allegro Hand$12,000+20x
Clone Hand~$2,800~5x
LEAP Hand~$2,000~3x
GEX GX11~$6001x

Note: Shadow Hand, Allegro prices reverse-calculated from paper-stated ratios (1/125, 1/20). Actual market prices may vary

Total Cost of Ownership (TCO) Perspective

GEX advantages go beyond initial cost:

  • Repair Cost: Immediate 3D print replacement when damaged (~$20/part)
  • Upgrades: Modular design allows individual finger replacement
  • Scalability: Multiple purchases affordable (dual-arm system $1,200)

Assembly and Usage

Assembly Process

  1. 3D Printing (2-3 hours): Print ABS parts
  2. Motor Installation (1 hour): Mount Dynamixel actuators
  3. Wiring (30 min): Connect TTL bus
  4. Calibration (30 min): Set position zero points

Teleoperation Setup

GX11 is used in combination with EX12 exoskeleton glove:

  • Total 23 DoF closed-loop system
  • High-fidelity control through kinematics retargeting algorithm
  • Indirect force sensing via torque estimation based on current control mode (no separate haptic sensors)

Limitations and Considerations

Current Limitations

  • 3-Finger Limitation: Tasks requiring 5 fingers not possible
  • Sensing: No separate tactile sensors (only current-based torque estimation available)
  • Waterproofing/Dustproofing: Research use, unsuitable for industrial environments
  • Payload: Heavy object manipulation limited

Suitable Applications

  • Data collection for VLA/reinforcement learning research
  • Demonstration learning based on teleoperation
  • Educational platforms
  • Low-cost prototyping

Unsuitable Applications

  • Industrial production environments
  • High-precision assembly tasks
  • Long-term continuous operation

References

  • Paper: Dong, Y., Liu, X., Wan, J., & Deng, Z. (2025). “GEX: Democratizing Dexterity with Fully-Actuated Dexterous Hand and Exoskeleton Glove.” arXiv:2506.04982
  • Actuator: Dynamixel XL330-M288-T

See Also