PCB Etching: Milling Method

This class will cover how to make your own PC Boards with MakeICTs PCB milling machine.

Sometimes the project just isn't complete until you have all the parts neatly soldered on to your own custom made PCB. In this class Tom McGuire will show us his favorite techniques for making an electronic project including making the PC board. We'll briefly go over designing circuits on a breadboard and trouble shooting them with some test equipment. Then we'll go over laying out the circuit board in Eagle PCB Editor. Members can follow along on laptops provided. And finally we'll make a board and solder some parts on to it . The machine can cut traces, drill holes, and do double sided boards.

Lesson Plan

  Welcome. My name is tom McGuire and I have been making PC Board for many years. 
  I was inspired by this companys product.
  http://www.lpkf.com/products/rapid-pcb-prototyping/circuit-board-plotter/protomat-e44.htm
   and went on to create my own machine which I posted in instructables.
  http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/

Discovery

  Design a basic circuit (the motor speed revers circuit)
  If you need ideas try a simulator http://www.falstad.com/circuit/index.html
  Industrial distributors with detailed search engines: Digikey, Mouser, Newark, Future electronics.
  Hobby suppliers: Sparkfun, Adafruit, Jameco, mpja.com, Allelectronics, Electronic Goldmine,
  Local Retail: Radio Shack(still has a few stores), Lloyds Electronics(220 W. Harry)  
  pull up the data sheet and look at all the specs
  [1]
  breadboard the circuit
  use the oscilloscope and discover where some caps need to go.

Document and layout

  Show the Eagle download page ([2])
  Show the PCB-Gcode downlosd page ([3])
  Start a new Schematic
  convert to PCB layout and arrange the parts
  run the traces (the fun part)
  Run the upl for PCB-gcode
  Look at the files in Jviewer
  http://www.thingiverse.com/thing:72324
  Or OpenScad
  http://www.openscad.org/

Make PCB

  Copy files to a thumb drive or transfer them to a shared drive on the LinuxCNC machine
  Place your board material on the bed
  Zero your Z,Y,Z axis
  Load your file top layer 
  (make sure M3 S1 is before the first move otherwise the spindle won't spin)
  Set any touch off offsets you might need to position the mill paths on the work surface.
  A little WD40 will keep the dust down and keep the bit sharp.
  Press Play (Oh and ware safety glasses)
  load the mill bit
  Zero the X,Y,and Z axis
  hit play
  Load the drill files
  Change the bit 
  DON'T RE-ZERO THE X or Y AXIS
  Just re-zero the Z axis for the drill bit
  hit play
  If your doing double sided board flip it.
  Align to some holes by moving the head around
  Press play again....
  Fin (you have a board)
  Cut off the excess board material with the metal shear or tin snips. 

Solder

  Clean up the board. You may need to peel some copper from a few places. 
  Heat the unwanted copper area with the soldering iron and lift the copper with an Exacto knife.
  Then grab it with some tweezers and peel.
  WD40 or Acetone helps clean the board.
  When soldering, always heat the joint with the soldering iron and then feed the solder into it.
  Let the solder flow. 
  If its too dry clean the tip of the iron or use some flux to wet the joint    again.
  Solder some parts on

Fin

  Hook it up and play with it

Want to setup Eagle on your computer?

  After you have downloaded and installed Eagle http://www.cadsoftusa.com/download-eagle/
  Download the PCB-gcode files from here http://www.pcbgcode.org/
  Depending on what system your running on you want to find out  where the Eagle program is keeping the .upl files and put the downloaded files in the same directory. 
  Here are some further instructions on how to use PCB-gcodehttp://www.pcbgcode.com/
  Here's a good instructables on doing it. http://www.instructables.com/id/Machining-a-PCB-Using-an-Inexpensive-CNC-Machine/