Custom CNC Machine

I needed a machine that could cut acrylic for the projects I was working on, and I'd rather build the tool than buy it. So I designed and built the CNC machine myself, repurposing 3D-printer components instead of starting from a kit.

The part I cared most about was the control side. I wanted to wire and configure the motor control myself rather than plug in a prebuilt controller box, which meant designing the interface between the drivers, the Arduino, and the machine.

The motion hardware came out of 3D printers: stepper motors, timing belts, and linear guide rods. Around that I designed my own frame and brackets in CAD, 3D printed the parts that had to exist, and assembled the axes by hand.

The lead screw couples to its stepper through a flexible coupler, which absorbs the small misalignments you get when a frame is built by hand instead of machined square. A lever-arm microswitch at the end of the rail marks the axis limit.

Motion control runs on an Arduino CNC shield with GRBL — open-source firmware I configured and integrated, not something I wrote. The work was the interface around it: adapting external stepper drivers to talk to the shield, and laying out the power and wiring to run them.

The drivers, switching supply, and Arduino live in an open tray I built for them, so the whole control stack stays accessible when something needs reworking.

I also printed and wired a handheld pendant with abort and resume buttons, so the machine can be stopped and restarted from the bench instead of at the computer.

After over 100 hours of development and testing it became a machine I actually use: it cut acrylic for the projects that came after it, including parts for the rocketry work on this site.