How to use the Modela

Roland Modela can be used to mill circuit boards.

Step by Step

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Modela buttons, from top: Power, View, Up, Down

1. Design the circuit board or select and download a cad file from the hello-world circuits section on the http://fab.cba.mit.edu/about/fab/ or from hello world electronics
2. Stick a piece of the PCB copper plated stock onto the cutting plane at the 1,1 inch intersection on the grid.
3. Open Cad.py software
4. Click input and get the design file (.cad file) or a pre-designed png file.

Make the toolpath

1. Open CAD.py in a Linux Terminal or click on the shortcut launcher in desktop.
2. Make the toolpath for the circuit. Use a 1/64" tool, which is 0.0156" decimal.
3. Click CAM
4. Click Output format and choose .rml (Modela)
5. If you're using a circuit board written in Python, you'll find a line near the bottom saying "#dpi = 500 ".
6. Move the ("#") sign to the line above which is "dpi=200
   • The "#" symbol is a comment, which will ignore the line of the command after the sign.
   • Use "dpi = 200 # low resolution for previewing" for previewing toolpath contour
   • Use "dpi = 500 # high resolution for machining" actual rendering and sending to Modela (takes longer to render)
7. Set contours to -1 (meaning infinite)
8. Click Contour

• This will set the toolpath for the file

Milling the circuit itself

Cutting out a circuit board

Milling a circuit

1. Go to "view mode" by click on the view button on the Modela
2. Tape down copper board at o,o position ( 1 inch x 1 inch from bottom left corner)
3. Put 1/64 inches bit in the modela, which is 0.0156" decimal. Set it up as high as you can in the machine. Loosen existing bit with provided allen wrench.
4. Clear out the memory of the Modela, by holding the both ""up" and "Down on the machine
5. Open file in cad...follow instructions "Make a toolpath"
6. Set the x,y axis starting point on the project to 1, 1 on the control panel in cad and then click "move"
7. Lower bit close to the corner (1,1) by pressing the "Down" button. Be sure to not let the bit touch the surface.
8. Loosen the hex screw that holds the bit and lower it until it touches the top surface of the board.
   • Lower it slowly so the bit doesn't fall into the board and break.
9. Now that the bit is at surface level, tighten screw.
10. Open cad again and then send to machine.
11. Grab a coffee, it's going to be a long night.

Cut out the Board from the PCB

1. Press view button to move PCB forward. Be careful not to move board around in process.
2. Clean up any shavings from first mill.
3. Change bit to the 1/32 inch bit (0.0312 )
   • Be sure it doesn't fall out and break
4. Open back up cad.py software
5. Change tool diameter to 0.0312
6. Change number of contours from -1 to 1
7. Change xy speed: to 0.5 and z speed: to 0.5
8. Remove the "#" in front of the lines...

#cad.function = pcb.interior
#z = -.065

1. Press contour to render contour lines for cutting out the board.
2. Press the view button place machine back in cutting mode and out of view mode.
3. In program cad.py move board back to position 1, 1 by clicking the "move" button in the program.

• repeat steps above to set bit

 Lower bit close to the corner (1,1) by pressing the "Down" button. Be sure to not let the bit touch the surface. 
 Loosen the hex screw that holds the bit and lower it until it touches the top surface of the board.
 Lower it slowly so the bit doesn't fall into the board and break.
 Now that the bit is at surface level, tighten screw. 

• Once bit is ready click on "send to machine"
• Press the view button to enter view mode and remove your new PCB Board

Finish

1. Clean the shavings with a vacuum cleaner
2. Clean the circuit board with water and soap. This prevent future corrosion

If something goes wrong

If something goes wrong during the milling process press the view button on the machine. To clean out the memory of the machine press and hold the Up and Down button at the same time until the LED besides the view button stops blinking.

If for some reason the above doesn't work (and it doesn't always-- especially with the modela print queue) you want to try to find other processes running on the computer and kill them. For example "cat" and "ttyS0" are the processes used for the Modela milling, so these are usually the processes that you need to kill. To find them and kill them, type the following into the terminal:

ps -ef | grep ttyS0  

(ps here represents "processes", and -e represents "everything", f represents full details on those processes, so this represents a global search on your computer for all the processes running related to the ttyS0 port)

This will show you what process is running in ttyS0, which is the port the modela is connected to. When you see the process number you type at the prompt:

kill -9 PID  (PID=process ID number)

Then check again to see if any "cat" process is running:

ps -ef | grep cat

(cat executes a command)

If you see a cat process running kill that too:

kill -9 PID 

Then reset the Modela by holding down the up and down buttons at the same time, and when the light stops blinking you're reset.

If you have the file.rml ready

If you have the file.rml ready and don't want to go to all the steps again you can open the terminal and write

cat file.rml > /dev/ttyS0

Using Eagle

A nice tutorial about this was written by people at the Delhi Fab Lab. It should be uploaded.

• http://fablab.marcboon.com/pcb/
• Circuit descriptons. pdf
• Scotts new Hello World Circuits description