Rebelia Robotic Hand

Description

This is the Rebelia Robotic Hand project, we aim to make a low cost robotic hand for humans and robots. The hand will be affordable and reliable. It will be produced in 2 versions: robotic ( for manipulators, humanoid and service robots) and prosthetic (transradial amputees). We believe that groundbreaking technology shouldn't be locked away in high-cost labs. It should be in the hands of developers, researchers, and makers like you. Join the rebellion. Let's build the future, affordably.

Details

https://www.robotgarage.org/wp-content/uploads/2024/10/output-7.webp

From Prototype to Product: Forging the Rebelia Robotic Hand

The Rebelia Robotic Hand works.

We've moved past the concept stage and have a functional prototype that has proven its basic reliability.

But now comes the hard part: transforming this prototype into a robust, consumer-ready product that can handle real-world tasks, and we need your help to do it.

Proven Durability: It's Not Just a Demo

Our latest stress test pushed the hand through 500 open/close cycles of all fingers with a 330 unit force limit.

The result?

The hottest motor stabilized at a cool 58°C. Even after 800 cycles, the temperature held steady, proving the design is stable for continuous use.

This isn't a fragile lab toy: it's a platform ready for refinement.

The Challenge: Beyond the Basics

A hand that can just open and close is useful, but a great hand can perform a vast range of manipulations.

We've identified key use-cases it needs to master:

use-cases picture taken from here, under CC-BY-4.0

But our list isn't exhaustive. What are we missing?

Suggest scenarios we haven't considered. Is it wielding a tool?

Manipulating a delicate object?

Performing a specific task in a workshop or kitchen?

An Open Invitation to Collaborate

This is a copy-left, open-source project. It belongs to all of us.

The potential technological solutions—from novel grip-pattern algorithms and sensor fusion to new materials and actuation methods—are infinite.

We challenge you to propose solutions, and we commit to implementing and testing the best ideas.

This isn't private, closed tech.

It's an open platform, it's affordable by design, and together, we can make it the best it can be.

Let's build the future of accessible robotics, together.

Components

1 × Creality Hyper ABS Filament Spool Skeleton and spools

1 × PolyFlex TPU 95A Filament Spool Fingers and palm

1 × Raise3D Pemium PLA Filament Spool Covers, fingers

5 × WaveShare ST3215HS Servomotor Tendon flexion and extension, Thumb rotation

1 × WaveShare ESP32 Servo Driver Board The brain of the hand

Project Logs

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[Ongoing] More DOFs and more weight DILEMMA
Vittorio Lumare • 11/06/2025 at 21:15 • 0 comments
[WIPWe are struggling to decide if it's worth adding more DOFs to Rebelia.

On the left, current version, on the right, the modified version.

It weights 150g more and has 2 extra DOFs .

The advantage of having more DOFs would be :
- possibility to move ring and little independently
- possibility to control the proximal joint of each finger, and this would allow a lot of more applications, like the Pinch Grasp.
Effects on the Pinch Grasp are shown here:

So .. what do you think? Shall we add 2 more DOFs or is better to save 150g ?

A new Hope

So, after reading your comments in the LinkedIn post, we decided to keep the hand lightweight.

In order to obtain more stiffness on the PIP joint, we increased its thickness as shown in the picture below.

Now the finger shall be more straight during the pinch grasp gesture.

We will test the feature and report the results soon.
[Solved] - Index got stuck while releasing an object
Vittorio Lumare • 11/04/2025 at 16:03 • 1 comment

The index finger got stuck during the releasing of a water bottle and then it stops moving.

Is anybody able to understand the reason for this?

While our team works on a solution, I ask to all you hackers to give some advice!
Automatic Tendon Calibration
Vittorio Lumare • 11/02/2025 at 21:05 • 0 comments
Basic Grasp Operations
Vittorio Lumare • 11/02/2025 at 21:04 • 0 comments
X X X Dangerous Situations ! !
Vittorio Lumare • 11/02/2025 at 20:59 • 0 comments

We want to show here all dangerous situations that happened to us, so you can be aware of them and take precautions to prevent accidents.
Upper Cover
Vittorio Lumare • 11/02/2025 at 18:28 • 0 comments

We mounted the upper cover on the hand..
Rebelia Naked
Vittorio Lumare • 11/02/2025 at 18:27 • 0 comments

Rebelia Robotic Hand..without covers.
Early Prototypes
Vittorio Lumare • 11/02/2025 at 18:23 • 0 comments

Early Prototypes of the robotic hand..
Installed PTFE Pipes
Vittorio Lumare • 11/02/2025 at 13:42 • 0 comments

During the STRESS TEST, an sequence of open/close actions repeated every 10 sec, the ring+pinky servomotor got overheated ( > 67C ), so we decided to reduce the friction of the tendons by tunneling them into PTFE pipes.

We installed pipes for the index, middle and ring+pinky flexion tendon.

After this we executed again the STRESS TEST, and the overheating problem was solved: the motor temperature set at 58C, please check this graph:

In green we can see the ring+pinky servomotor, setting at 58C after 800 repetitions.

The CAD was updated as in the screenshot below.

In RED: the PTFE pipes.

In BLUE: the pipe holders, incorporated into the skeleton part.

PROBLEM: Now, how do we lock the PTFE pipes in the holders ?
We tried with Loctite unsuccesfully, it doesn't work with PTFE !!

View all 9 project logs

Build Instructions

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Health and Safety

The following section explains the meaning of the symbols used throughout the manual. Please make sure you have grasped the meaning of each relevant symbols to prevent dangerous circumstances.

READ INSTRUCTIONS MANUAL

MANDATORY USE OF THE VICE

MANDATORY USE OF THE PLIERS

DO NOT SPRAY LIQUIDS ON THE GRIPPER

DANGER OF CUTTING FINGERS BY TENDONS

DANGER OF FALLING OBJECT FROM ABOVE

DANGER OF FLYING OBJECT

DANGER OF FIRE

DANGER OF HOT SURFACES

DANGER OF CUTTING BODY PARTS

DANGER OF CRUSHING BODY PARTS

DANGER OF HARMFUL SUBSTANCES

DANGER HIGH VOLTAGE ELECTRICITY

Maintenance

!! DO NOT PULL TENDONS WITH YOUR BARE HANDS !!

MANDATORY

Use the vice to hold still the part to be worked on
Use the pliers to pull the tendons

POSSIBLE INJURIES:

Severe cuts to fingers
Severe bleeding requiring immediate surgery

Put in Service

BEFORE TO PUT IN SERVICE THE COMPLETE MACHINERY WHICH WILL INTEGRATE THE GRIPPER, THE FOLLOWING SYMBOLS MUST BE APPLIED TO THE FINAL PRODUCT, SO THAT THEY ARE ALWAYS VISIBLE TO THE PEOPLE PRESENT IN THE VICINITY

Normal Functioning

People near the Gripper

ATTENTION: the gripper could break while using the machinery!

POSSIBLE INJURIES: If the gripper breaks, some broken parts may be sharp or pointed and could cut people's skin and cause permanent injuries or bleeding and/or require immediate surgery.

Gripper holding an object

ATTENTION: An object could break away from the gripper and hit a person.

POSSIBLE INJURIES: A thrown object could cause: broken bones, cutting or piercing, or burns if it’s very hot, or contamination if it contains or is made from harmful substances.

Interaction with people

ATTENTION: Fingers or human skin can get caught in the machinery mechanisms and get severely injured.

POSSIBLE INJURIES: A finger can be crushed, causing severe bruising to the skin or nails. A nylon tendon can cut a hand finger, causing bleeding where immediate surgery is required. Sharp edges can cut the skin, causing bleeding or bruising.

Discussions

Rebelia Robotic Hand

Description

Details

Components

Project Logs

Collapse

[Ongoing] More DOFs and more weight DILEMMA

A new Hope

[Solved] - Index got stuck while releasing an object

Automatic Tendon Calibration

Basic Grasp Operations

X X X Dangerous Situations ! !

Upper Cover

Rebelia Naked

Early Prototypes

Installed PTFE Pipes

Build Instructions

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