Watch Ivan Miranda 3D Print Another Metal-Cutting CNC Mill

Ask any machinist what they think about milling metal on a plastic CNC machine and they won't be able to answer you, because they'll be too busy laughing in your face at the prospect. Milling metal requires an extremely rigid machine, which is why CNC mills have heavy iron or steel frames. But if you don't require tight tolerances, a CNC mill with plastic components isn't as absurd as it seems at first. Ivan Miranda's 3D-printed CNC machines prove that and now he's back with a new compact design.

Miranda built several CNC machines in the past using 3D-printed plastic parts, from light duty CNC routers for cutting wood to CNC mills that can cut soft metals like aluminum. The latter may not be capable of machining metal at the kinds of tolerances one would expect from a modern professional CNC mill, but they can produce respectable parts that are suitable for most hobby purposes. However, Miranda's previous machines were very large and cumbersome, so he designed this new machine for convenience.

As with Miranda's previous designs, this machine has a frame made of a combination of aluminum extrusion and 3D-printed plastic joints. Each axis rides on smooth hardened steel rods and stepper motors drive the axes using heavy duty belts. The steppers are on the smaller side, but Miranda geared them down using belts for torque. An Arduino Uno with a CNC shield controls the stepper motors. The spindle is a powerful handheld Makita router. The work envelope is 234 x 294 x 60 mm (9.21 x 11.57 x 2.36 inches) before adding the spoil board. In the demonstration, this little CNC mill seems to handle aluminum well enough with light cuts.

If you want to build your own machine based on this design, the plans are available for sale on Miranda's website.