Eagle CAD
PCB to G-CODE
A good guide for using the plugin has been made by Richard Albritton.
You will also need the following hardware:
- CNC machine that can take the PCB size.
- CNC bed bracket to hold the board down.
- Double sided copper clad board.
- A 30 degree angled bit with a tip of 0.01"
The first step is to create the circuit diagram that will be turned into a PCB. This can be done with Visio, Pspice, Eagle CAD, paint, or pencil and paper. The following circuit was created using Multisim.
After a circuit is created, the next step is to use Eagle CAD to draw the traces. Eagle CAD's website has a few tutorials to try out if you do not have any experience with it. Be sure to set up Eagle with the PCB to G-code plugin! As once the traces are made, that plugin will be used to turn the file into G-code. Use Richard Albritton's tutorial when setting it up and converting to G-code. The Gcode can be read by the software your CNC machine is compatible with. MACH3 was used with this project.
You may notice that a few of the holes are off or the pad (the CNC was manually controlled to make the corrections). This is because a 3020T-D CNC machine was used. The control board it uses is less than perfect, and may cause a few skips in the movement count. After the above PCB was created, some 0.47micro capacitors were connected between the ground plane (The trace going under the surface mount resistors) and pin 6 of the axis controller. The negative side of the electrolytic cap was connected to the axis controller.
After the fix, the output to each axis was MUCH cleaner and stopped skipping steps! The board that was not cut perfectly was still functional, so it was used for it's intended purpose of controlling two matrices of LEDs based upon a microphone input.
As a bonus, print the description of each component on a clear sticker sheet and put it on the front of the board. This will make populating the board that much simpler.
