3D Printer as a milling machine

(updated in October 2025)

One of the first projects I want to share, because so many people have asked about it, is how I converted my old 3D printer into a CNC milling machine. I primarily followed this guide by Noah Meurer and adapted it to fit my specific needs.

For a study project, I needed to mill a circuit board, so I decided to repurpose my 3D printer for the task. The process involved replacing the hotend with a Dremel tool, updating the firmware to disable temperature regulation (since a hotend is no longer required), and 3D printing a custom mounting bracket for the Dremel’s flexible shaft. Before proceeding with the conversion, I printed the necessary bracket, which you can find here.

One of the biggest hurdles was reducing vibrations and ensuring smooth motion at cutting speeds. I had to fine-tune feed rates and experiment with different tool paths to get clean cuts. The first milling passes revealed areas for improvement, as seen in the image below:

Through optimization—adjusting parameters such as feed rate and cutting depth—I was able to achieve significantly cleaner cuts:

Ultimately producing my first successful circuit board:

The conversion has opened up new possibilities—from engraving designs to cutting soft materials like wood and acrylic, which I definitely want to try out next.

If you have any questions regarding the project, don’t hesitate to contact me.