About one and a half years ago I started a project together with a friend. Our goal was to be able to directly drill PCBs. The result was a relatively big portal-CNC-mill.
The workpiece is moved along the X- and Y-Axis and the tool is providing the remaining Z-Axis. The three stepper-motors are controlled by an atmega32 microcontroller. All PCB’s on the rear of the device are made by the device itself. This was possible because at that time, most of the parts were just hacked together mid-air or on breadboards.
The mill is communicating with the PC via a simple USB-to-RS232 converter and is talking some strange custom protocol. On the PC-side I am running a very crude python-script that can basically just parse HPGL. I plan to rewrite everything in Java. This allows me to have a nice GUI and it makes keeping the code clean much easier.
Here you can see the mill in action. It is drilling the shackspace logo inÂ acrylicÂ glass.
Since we used stepper motors and stepper motors make noise, we can also have fun with them.
On those two pictures you can see the the device painting on a PCB with permanent ink. Notice the high precision of the drawn lines.
This is a snapshot while drilling the holes in a PCB.
This was one of our first attempts in two-sided PCB’s. As you can see, the alignment worked quite well. However, some of the signals lines dissolved during the etching process.
Feel free to comment and ask for more details. It is always hard to explain everything at once, so if you want to know something specific, just ask.
You will find more blogposts about the mill over at http://project-insanity.org