For many years I wanted to have a way to make my own PCB prototypes, but I didn’t like the idea of using chemicals for masking and etching. Both because I was afraid of the chemicals and also because wasting and disposing those materials didn’t feel very ecological.
So a couple of years ago I started this project of creating a CNC mill that could be accurate enough for milling PCBs. I could then use it for other purposes as well.
The first version of the CNC (Mk1) was quite accurate, but not very sturdy and incredibly slow! It was based on simple aluminum profiles for the chassis and linear guide.For linear drives I used long brass screw rods and some old step motors I had around. As a controller board I was using an Arduino.
You can see more details about CNC Mk1 here.
The second version of the CNC (Mk2) was a bit less accurate but much faster and a bit more sturdy. But apparently not sturdy enough. The brass screw rods were replaced by timing belts. The linear guide system was changed to use some V-groove bearings running on the edge of aluminum profiles. The step motors with some stronger step motors from an old photocopier I disassembled. Another design change was that the spindle was now moving along the X-axis and Z-axis (while on the Mk1 it was only moving along the Z-axis). The mounting plate of the material was moving only on the Y-axis (on Mk1 the material was moving both on X-axis and Y-axis). In the mean time I have designed my own control board and replaced the Arduino.
You can see more details about CNC Mk2 here.
The third version of the CNC (Mk3). The linear guides are being changed again to use LM8UU linear bearings on 8mm steel rods (taken from the photocopier I disassembled). That made the CNC sturdy enough. The control board is also replaced with the latest design of my FlexNC control board, which resolves some overheating issues.
You can see more details about CNC Mk3 here.