How to build a hand

Difficulty level: Beginner

Approx reading time:

In this tutorial you will learn how to assemble a robot hand. This hand has one degree of freedom per finger, so it is easy to slave them to the same actuator to have a simple grasping hand, possibly with a separate actuator for the thumb.

To build the hand, follow this tutorial :

Materials :

Prepare this list of materials before starting.

3D hand – The model can be found here, for printing yourself or ordering :

To make the finger with a 3D printer download the parts from thingiverse, print and clean up.

tuto_mech_hand-0If you order it on Shapeways, it comes already pre-assembled. The hand has a lot of details which has a specific function.

Ball bearings – each finger has 3 joints with 2 bearings, so 30 in total.

Caracteristics of the ball bearings :

Bore : 6 mm
Outer Diameter : 10 mm
Width : 3 mm

You can find them here.

It’s also very useful to use one 6*10*2.5 bearing to put inside the finger joint during assembly.


Fishing line – use for lacing the fingers and form the joints. You will need a lenght of 40cm for finger top joints, and 50cm for the middle joints.


Elastic  – for making spring load mechanisms, for the finger return.


Superglue – a slow setting liquid for gluing the elastics.


Cable – use nylon cables to pull the fingers.

Teflon tube – This can be used under the finger sections to help the action of the cables pulling the fingers.

Read full tutorial at

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