PCB milling on the Modela

PCB Milling on the Modela MDX-15

Here the pertinent steps in PCB milling on the Modela are covered, but it is not intended to act as a stand alone tutorial and so please ask for assistance from other members if you are unsure about anything.

A video tutorial of the tool can be found here [1] and is a great starting point.

Importing your PCB image

• Open a terminal and type 'fab', press enter.
• On the import menu select 'PNG' and on the output select 'Roland MDX-20'.
• Press make_png_rml
• A new window opens, at the top menu change from 'default' to 'mill traces (1/64)'
• To the left press 'load.png' and select your image file. Note that on the displayed image, black is copper to be milled and white is copper traces that will remain. You can invert the image here by pressing 'invert.png' if your image is the opposite to this convention. Similarly, you can resize your image here by pressing 'resize.png'.
• To the bottom right are some inputs:

   Diameter (mm) - This is the diameter of the end mill and should be 0.40 mm (~1/64")
   overlap (0-1) - this is the overlap between neighbouring traces.
   intensity (0-1) - This is how deep a single pass will mill into your work piece. For example, if z is -0.1mm and intensity is 0.5, the circuit will first be milled as two layers, the first to a depth of 50um and the second to a depth of 100um. 
   Offsets - this is the number of mills that will be done at an edge.
   Error (pixels) - No idea
   z (mm) - the total depth to which traces will be milled.

• When all inputs are correct press 'make.path' and the software will calculate the milling path; this can take several minutes depending upon the complexity of the circuit, and will be displayed in the right box when done.

Setting up the Modela

If no lights are visible on the right, turn on the Modela (green button). Select your end mill and attach it into one of the brass collets, tightening the grub screw. Insert the collet into the bottom of the motor shaft, tightening the two grub screws. If the stage is at the front, the Modela is in view mode and so press view (white button) to position your piece ready for milling.

In the software, now enter some value into 'xmin (mm)' and ymin (mm)' to position the end mill above your work piece. Note that the end mill spins when moving for the first time. There is no input in the software for the height of the end mill, this must be calibrated manually on the Modela and with care.