BrachioGraph

The world’s cheapest, simplest possible pen-plotter.

BrachioGraph - arm-writer - is an easy-to-build pen-plotter, driven by a library of simple Python applications.

BrachioGraph plots cheerful, low-fi drawings, and can produce robotic sketches using a variety of drawing implements.

A BrachioGraph can be built for about €15 in an hour or so, using a Raspberry Pi computer, hobby servo motors and household items. The BrachioGraph library is published on GitHub and includes simple Python code to drive the plotter and vectorise bit-map images.

In this documentation

How this documentation is organised

This documentation uses the Diátaxis documentation structure.

  • The Tutorial takes you step-by-step through the process of building the machine, installing the software and making your first drawings.

  • How-to guides assume you have basic familiarity with the BrachioGraph. They go deeper into problems and explore things you can do with the system.

  • Reference provides a guide to APIs, key classes and functions.

  • Explanation includes topic overviews, background and context and detailed discussion.

From bitmap to plot via vectorisation

'Anselmo' 'Prague'

Community contributions

BrachioGraph is a hobby project, and I have very limited time to work on it. It means that I don’t have the capacity to answer the many questions I get, or even to give due consideration the numerous offers of improvement.

Other people in the open-source community have created their own resources for working with BrachioGraph.