Design Overview

X1M focuses on developing an advanced mechanical design that maintains a high functionality whilst being modular and maintaining ease of assembly. The hand mainly functions off of a configurable whippletree block that drives two removable finger modules (index & middle, ring & pinky) when actuated. Driving the actuation is a configurable 1 to 3 stage block and tackle pulley system to provide mechanical advantage or shorter actuation for use with motorised attachments. Additionally, alternative attachments may be placed on the back of the palm using the additional mounting holes. The thumb on the hand is also a removable module for a fixed thumb or an actuated thumb. Wrist can be rotated 180 degrees with 7 indented positions that can be adjusted for varying stiffness.  

Design Features

Hand Design


3D Printing

The ARX Hand Project can be printed using any standard FDM printer that can print PLA. Majority of prototypes I have printed are in PLA using a fairly modified RepRapPro Huxley 3D printer purchased in 2014. The design has been based around 0.2mm layer height with a 0.4mm nozzle, so using different parameters may affect part fit. Some additional small geometries have been added to the models to compensate for some effects caused by 3D printing.

No supports are needed when printing out all parts, however, if there's inadequate cooling of the undersides of joints, supports may be needed. Parts can be printed without brim for materials like PLA and PETG, but bed adhesion should be made as strong as possible for finger joints as they are prone to warping due to their length. The use of a removable flex bed is recommended to allow for easy part removal if print is adhered strongly to the bed.

Typical print specifications:

Print materials:


ARX X1 Variants 


Although I have experience in designing things from being self taught, I do not have any degree or qualification as of writing. This design therefore should not be used as a medical device or to be used in any situations where it may cause injury or harm. I can not be liable to any injuries, harm, or issues resulting from the design and therefore should only be used at your own discretion.


This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.