Welcome to Praxis Guitars

Since 2011, we have developed and manufactured new music technologies in Denver Colorado.


Praxis Guitars uses digital fabrication technology & traditional craftsmanship to create affordable custom instruments. The use of computers to control carving tools has been popular in the world of instrument building for many decades; we affirm that by building our own machines, and sharing design files, we can dramatically reduce the cost of customized instruments, and create a positive sum in the realm of human art.

Praxis Guitars creates open source musical instruments by encouraging other makers to modify & sell copies of our instruments. By sharing the digital design, the product becomes more valuable than a similar product held behind the curtain of proprietary secrets. The ethos of Praxis Guitars is to enable musicians to become an active part of ongoing instrument designs & production.

The instruments we create are licensed under Creative Commons Share Alike Attribution licensing. The licensing allows for commercial replication & modification as long as the original design is properly attributed, and derivatives are given the same license.

Order a custom instrument from our store!


The Praxis Zero is a modular guitar design, where different parts can be attached to a central frame.

Different components fit together to enable experimentation in both the sound and feel of the instrument.

Marabunta is a parametric instrument generator capable of creating anything from a pocket ukelele to an enormous multiscale 6 string bass.

A skeleton file shapes the instrument from control variables, such as the string lengths and the amount of space between each string. Once a design is chosen, the system automatically creates instructions for a team of robots and luthiers to complete your instrument in the materials of your choice.


Praxis Guitars LLC was founded in 2011 by Andrew Benson to explore the concept of open source guitars. The dream goes back to 2005, when Andrew wondered what would happen if people shared guitar designs openly, and could fabricate them with automated machinery.

Andrew learns to translate code into guitars

Praxis Guitars originated at Club Workshop, a hackerspace in Denver, where the equipment required could be rented for a low monthly fee. After a year of prototyping different designs, Andrew took the project to the Bay Area Maker Faire in 2011.

As development continued, a kickstarter was launched to buy a CNC wood router for the company. When the requisite funding was not reached, development moved to software, where iteration was much cheaper.

The Kimura Gumo after the final coat of Tung Oil

The Kimura Gumo was carved by hand in 2013 to provide a test bed for digitally capable guitars. The guitar has undergone many different changes to scope and hardware, evolving over the years. This guitar was the basis for the “Wizard Class” of guitars offered during the next kickstarter, which also did not reach funding.

The Kimura Gumo in 2016

Not long after the second kickstarter, Andrew was homeless and living in his van. During that time, Praxis Guitars kept moving forward, with a custom CNC built in a friend’s garage.

It was a comfortable van to live in.

It took several years to scavenge and purchase the parts to build the first CNC. The first iteration of the machine had trouble with precision, and so it upgraded itself with some scrap aluminum.

The Praxis Guitars CNC was built from scratch, almost entirely out of scavenged materials.

Praxis Guitars has been bootstrapping itself ever since, recently acquiring a potentially permanent home for the business in Denver, CO. Feel free to browse the instrument archive as well.



Well, Marabunta did not advance to the finals for the hackaday prize. The project will continue, and at least we made it to the finals through another personal project: Fluid Displacement Thermal Actuators.


We are working on a new parametric instrument generator called “Marabunta”. This is the continuation of the hornet; but it turns out someone already has a hornet bass on the market, so we went with the name “Marabunta” to avoid confusion. Marabunta is being entered into the 2018 Hackaday Prize, and you can follow along …