DIY CNC

Motivation

CNC machines are incredibly useful, and it is fun to build your own. At my workplace they agreed to support with equipment needed if we invested the time. We did a complete rebuild of a Manual Milling Machine and added stepper motors and software to control it as a CNC

The CNC in action. It’s possible to mill a lot of pieces.

Process

Rebuild

Our strategy was to a milling machine, and then rebuild it into a CNC using stepper motors. Because the milling machine probably was a little too cheap, my colleagues made a redesign on the spindle, and use much higher quality spindles than it was originally equipped with.

Generating CAM code

Finally we tested the CNC on a part. We used Autodesk Fusion as CAM software and one of their standard components.

Milling

From the software the G-Code is generated which can be transferred to the CNC mill.

Milled Pieces

After milling the piece of aluminium, we got this final showpiece

Final Results

Because we were also on a budget, we tried to keep motors, and motor controls as cheap as possible. Also the software could not be too expensive. To achieve this, we used stepper motors that are open-looped which limits precision of the mill as compared to closed-loop servo-motors for example.

We managed to achieve precision within 0,1 mm most of the time, but sometimes it was within 0,3 mm for unexplainable reasons. It was a really cool, and even useful project and there are plenty of room for optimizations.