The Heads on Fire Community

We are using the Modela MDX-20 and cad to mill out circuit boards.

Step 1: Setting up the machine and board

Place a sacrificial layer like an old PCB stock sheet at square(1,1) with double-sided tape (make sure it is flat, otherwise, the board will not be milled properly).

Place the PCB sheet you are milling at square(2,2) also with double-sided tape.

You will be using a 1/64 bit for milling the traces, and a 1/32 bit for cutting the board.

So start with the 1/64 bit, loosen the screws and place the bit in, tightening just enough, but not too tight :)

In terminal, type: move 1 1 (that moves the x and y, respectively)

On the machine, use the up and down button, to adjust the z position. Get the tool as close as you can and then manually lower it (by untightening screws, letting the bit touch the board, and then re-tightening the screws). This is how you zero the bit.

Step 2: Uploading file and changing settings in cad for milling

You can either upload a png or a cad file.

- Using a png file:

     set z min to -.005

     set z max to 1

     set x min and y min depending on the location of your board.

     set contour to -1.

     set the tool diameter to 0.0156 (that's 1/64)

     set xyz speed to 4.

     Contour and save the file (don't send to machine).

- Using a cad file:

     some uncommenting to do(these are usually towards the bottom of the files:

          make sure that dpi is set to 500:                   dpi = 500 # high resolution for machining

          make sure that this line is uncommented:     cad.function = pcb.board

     and then make sure all the other settings mentionned for the png are the same.

Step 3: Sending the file for milling

Since sending the file from cad does not always end up with a complete board, we save the file and then send it through terminal.

cat myFileName.rml > /dev/ttyS0

Step 4: Uploading file and changing settings in cad for cutting

set z min to -0.065 (width of the board).

set z max to 1

set x min and y min depending on the location of your board (same as when milling).

set contour to 1.

set the tool diameter to 0.0312 (that's 1/32)

set xyz speed to 0.5.

We left nz at 1 and the modella was just fine cutting the board out with one pass at that speed.

Contour and save the file (don't send to machine).

Step 5: Sending the file for cutting the board

Same as with sending to mill, go through terminal to be sure the Modela completes the traces.

cat myFileName.rml > /dev/ttyS0