Making Printed Circuit Boards with the Fab Lab by Marc Boon
What is a Fab Lab?
From the MIT website: “Fab Lab is an abbreviation for Fabrication Laboratory. It is a group of off-the-shelf, industrial-grade fabrication and electronics tools, wrapped in open source software and programs written by researchers at the Center for Bits and Atoms. Currently the labs include a laser cutter that makes 2D and 3D structures, a sign cutter that plots in copper to make antennas and flex circuits, a high-resolution milling machine that makes circuit boards and precision parts, and a suite of electronic components and programming tools for low-cost, high-speed microcontrollers.”
There are many FabLabs around the world. In Amsterdam alone there are 3. I worked with the FabLab at Mediamatic to develop a procedure for making printed circuit boards, and led a workshop for 15 people, who had never used a Fab Lab before, to successfully build a Micro TV transmitter in just one day.
For more information on FabLabs in Holland see FabLab.nl (in Dutch).
Making Printed Circuit Boards with the Fab Lab
The goal is to fabricate a single-sided, through-hole printed circuit board (PCB) using the FabLab's milling machine: the Roland Modela MDX-20. There are already several published methods to accomplish this, but I developed a work flow that requires less steps to follow, and less software packages to install.
A main objective is to create a work flow that uses free and/or open-source software and will run on Windows, Mac and Linux platforms.
The only software tool I use is the free-ware version of the Eagle Layout Editor, a software package for designing electronic circuit schematics and printed circuit board layouts. The free-ware version is limited to non-commercial use and to maximum board dimensions of 100x80 mm. The output files of Eagle can directly drive the Roland Modela milling machine.
Depending on your platform, the following software has to be installed on your computer:
Eagle 4.16r2 for Windows
Mac OS-X (10.3 or higher):
X11 update for OS-X (might already be installed)
Eagle 4.16r2 for Mac OS-X X11
Eagle 4.16r2 for Linux
As an example project, I use the Micro Silent TV circuit by Tetsuo Kogawa. This is a very simple TV transmitter circuit which will broadcast a composite video signal in the VHF band. Using this circuit, the composite video signal from a camcorder or from the TV-out socket of a pc can be received on a nearby (max. 10m distance) portable TV equipped with an antenna.
Tetsuo Kogawa developed a very simple and effective way to build this or any other circuit, without the need for computers, software or a FabLab, but for those of you insisting on using the FabLab, follow these steps:
Step 1: Creating a PCB layout in Eagle
Using Eagle for schematic entry and pcb layout, with design rules for milling with the FabLab.
Step 2: Creating a tool path for milling and drilling
Defining the contours of pcb traces and holes to be milled and drilled.
Step 3: Creating files for driving the Roland Modela milling machine
Using Eagle's CAM Processor to generate output files for the Roland Modela milling machine.
Step 4: Milling and drilling the pcb
Sending the files to the milling machine, which will fabricate the boards.
Step 5: Soldering and testing
Soldering components to the board, hooking up a video source and start broadcasting!
More info: fablab.marcboon.com/pcb/