About terraPen

Two makers, an open-source pen plotter, and a growing pile of finished drawings.

What we build

terraPen is a CoreXY plotter on linear rails, with wireless control and a solenoid pen lift, designed and built in the UK for artists, studios and universities producing large-format work. It's open-source by design — the electronics and firmware are on GitHub, so nothing about it is a black box.

Where it started

TerraPen is the result of Mark and Ed's fascination with drawing machines, born from their involvement in the Reprap 3D printer movement of the early 2010s. As they built Reprap printers, they discovered the endless possibilities that lay before them. Mark's experiments with 3D printed 'Eggbots' and a fortuitous visit to a hackathon sparked their interest in building a Polargraph from scratch.

Their paths crossed at the local Reprap User Group, which eventually transformed into the hacker space community known as 'MakeBmth'. While MakeBmth pursued various projects, they always returned to their passion for drawing machines. Mark continued refining Polargraphs, while Ed ran the group and envisioned a CoreXY string bot for his next plotter. The limitations of string-based movement became apparent, prompting Ed to explore alternatives during a lockdown period. He iterated on the design, transitioning to more conventional belts, while Mark focused on the electronics and open-source firmware.

This intensive two-year period laid the groundwork for a potential product. Ed's collaboration with AUB (Arts University Bournemouth) turned the plotter into a research project, named terraPen. Generative artists were given sample machines to experiment with, resulting in captivating artwork displayed at AUB's exhibition and plotter symposium in late 2022.

Building on this success, Mark and Ed have since been refining terraPen, iterating and testing the design, with a goal of giving artists and creators a tool that expands their creative expression.

Meet the team

Ed Ward	Mark Benson
Artist, Designer and Founder Mechanical design and vision	Artist, Designer and Founder Electronics and firmware

Built to last

Most of terraPen is aluminium and recycled-plastic Ekoply, chosen to be recyclable at end of life. Because the electronics and firmware are open-source, machines can be repaired long after we've moved on to the next revision — and we're working on a buyback programme to refurbish and pass machines on to schools and universities. More on the Sustainability page.

Get in touch

General enquiries via the Contact page. For build help, firmware questions, or just to show us what you've plotted, find us on Discord or Instagram, or dig into the code on GitHub.