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DIY robot concept

How to make a robot hand

A tendon-driven hand build with servo actuation, flexible fingers, force limits, calibration and safe grip experiments before prosthetic claims.

A robot hand is a mechanics and control project. Fingers need compliant joints, tendons or linkages, enough grip force and a way to avoid crushing objects or stripping servos.

Start with one finger, then two-finger pinch, then a full hand. Avoid medical or prosthetic claims unless you are working under the proper engineering and regulatory process.

Core parts

3D-printed fingers

$20

Light joints with elastic return or hinges

Tendon line or linkage rods

$8

Transfers servo motion to fingers

Micro or standard servos

$35

Finger actuation

Servo driver board

$7

Stable multi-servo PWM

ESP32 or Arduino controller

$8

Grip commands and calibration

Force or flex sensors

$20

Optional grip feedback

Design variants

One-finger test rig

Tune tendon routing and joint return before scaling up.

Two-finger gripper hand

Useful pinch grip with simpler control.

Five-finger demo hand

More expressive, but harder to wire and calibrate.

Practical safety note

Treat the generated output as a prototype plan, not a certified product. Body-adjacent, high-voltage, optical-energy and mobility builds need qualified review before real-world use.

FAQ

Should I use tendons or linkages?

Tendons are compact and hand-like. Linkages are easier to debug and print accurately.

Can it be a prosthetic hand?

Do not treat a DIY demo as a medical device. Keep it educational unless properly engineered and reviewed.

Why do servos buzz?

Binding fingers, too much tendon tension or weak power rails are common causes.

Robot build paths

How to make a robot

Related robot guides

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