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TriFinger Edu v1

The TriFinger Edu is a 9-degree-of-freedom manipulation platform consisting of three identical finger modules mounted on an aluminum frame structure. The platform is designed for dexterous manipulation research and learning.

Overview

Degrees of Freedom

9 DOF - 3 actuated joints per finger

Finger Modules

3 identical torque-controlled fingers

Weight

930g per finger module

Total Platform

8kg complete platform weight

Key Specifications

SpecificationValue
Degrees of Freedom9 DOF (3 per finger)
Finger Module Weight930g each
Number of Fingers3
Total Platform Weight8kg (with frame and cameras)
Frame MaterialT-slotted aluminum profiles (Item Size 8)
WorkspaceDefined by barrier: 3mm polycarbonate sheets

Mechanical Design

Finger Modules

Each finger module consists of three torque-controlled actuator joints:
  1. Base Joint: Controls finger rotation around vertical axis
  2. Proximal Joint: Controls middle segment angle
  3. Distal Joint: Controls fingertip segment angle
Weight: 930g per assembled finger module All three finger modules are identical and use the same components. For complete finger module details, see the Finger Edu Documentation.

Frame Structure

The frame uses Item aluminum profiles (Size 8, 40mm x 40mm): Aluminum Profile Segments:
  • Vertical supports: 3 profiles
  • Horizontal base: 3 profiles
  • Custom cut lengths per assembly drawing
Frame Components:
  • 3x 90-degree large angle brackets (Item 0.0.411.32)
  • 9x end caps (Item 0.0.026.01)
  • M5 T-slot nuts (Item 0.0.480.54)
  • 3D printed center connector

Workspace Barrier

Polycarbonate Barrier:
  • Material: 3mm polycarbonate sheets
  • Configuration: 3 sheets forming triangular workspace
  • Purpose: Contains objects within manipulation area
  • Custom cut to size per assembly drawing

Camera System

The platform includes integrated vision: Basler Cameras (3 cameras):
  • Model: acA720-520uc
  • Lens: Basler C125-0418-5M
  • Mount: Custom 3D printed camera arms
The cameras provide visual feedback for manipulation tasks and object tracking.

3D Printed Components

All parts should be printed in the positive Z direction of the STL files.

Frame Center Connector

Joins the three vertical aluminum profiles at the center

Camera Mounts

3 camera mounts for Basler cameras

Assembly

Frame Assembly

Tools Required:
  • 6mm hex driver
  • 6mm allen key
Assembly Steps:
  1. Cut aluminum profiles to specified lengths
  2. Install center connector on vertical profiles
  3. Attach angle brackets to horizontal base profiles
  4. Mount finger modules to frame
  5. Install barrier sheets
  6. Mount cameras on arms

Finger Module Attachment

The three finger modules are mounted at 120-degree intervals around the central workspace, creating a symmetric manipulation platform.

Applications

The TriFinger platform excels at in-hand manipulation tasks, including object reorientation, precise placement, and dynamic manipulation behaviors.
With integrated cameras, the platform is ideal for learning-based manipulation research, including visual servoing and object recognition.
The three-finger configuration enables research into coordinated multi-appendage control and contact-rich manipulation.
The TriFinger platform was used in the Real Robot Challenge, a global competition for robotic manipulation using real hardware and simulation.

Transport and Storage

Compact Storage:
  • Finger modules can be stacked for transport
  • Complete platform fits in 1650 Pelican case
  • Total transport weight: 21kg (with case)
Portability:
  • Modular design allows easy disassembly
  • Aluminum frame can be reconfigured
  • Suitable for lab-to-lab transport

Alternative Configurations

Upside Down Operation

The manipulation platform can be mounted upside down:
  • Inverts workspace orientation
  • Changes gravity interaction with objects
  • Enables different manipulation strategies
  • Same mounting interface

Bill of Materials

ComponentQuantityNotes
Finger Edu Modules3Custom assembly
Aluminum Profiles (40x40mm)VariousItem Size 8, custom lengths
90° Angle Brackets3Item 0.0.411.32
End Caps Size 89Item 0.0.026.01
T-Slot Nuts M5MultipleItem 0.0.480.54
Frame Center Connector13D printed
Camera Mounts33D printed
Basler Cameras (acA720-520uc)3With C125-0418-5M lenses
Polycarbonate Sheets (3mm)3Custom cut to size
FastenersVariousPer assembly requirements

Electronics Integration

Each finger module includes:
  • Brushless motor drivers
  • Encoder interfaces
  • Power distribution
The platform requires:
  • 24V power supply
  • Ethernet communication to control PC
  • Camera interfaces (USB or Ethernet)
For complete electronics details, see the Finger Edu Documentation and Electronics Wiring Guide.

Workspace Dimensions

The triangular workspace is defined by:
  • Center-to-finger distance (radius)
  • Barrier height
  • Finger reach and range of motion
See the visualization model for complete workspace dimensions.

Finger Edu Module

Complete finger module build instructions

Actuator Modules

Core actuator module documentation

Electronics

Electronics and motor driver details

CAD Model

Interactive 3D CAD viewer
The TriFinger Edu platform shares core components with the quadruped and biped robots, including the same actuator modules and electronics. This modular design approach reduces costs and simplifies maintenance.

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