Electronics Production

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  1. Generating rml files for the milling machine
  2. Milling machine
  3. Arduino IDE
  4. Downloadfiles

Generating rml files for the milling machine

Making the images

For the pcb we have got two files.
I am going to open them in Autodesk Eagle. The software is free for students to use.
This is the schematic:

pcb

To mill and cut the board with the milling machine we need two files.
For that we open the board file.
You can see that there are many descriptions.

pcb

To remove them click on layers.

pcb

Select hide layers.

pcb

Click again on layers and select these layers to show.

pcb

Now we still have descriptions.

pcb

To remove them go to options.

pcb

Click on settings.

pcb

Go to misc and remove these four checks.

pcb

Your board should look like the lower picture. Make sure to zoom in the board with a little offset.
Go then to file > export > image.

pcb

Save it as "inside" with the following settings.

pcb

Your image should look something like this.

pcb

Now you can choose an editor you like for example GIMP to crop and color the picture.
This should be your new inside file.

pcb

Now you color the whole board.
This will be the outside of the board. Save it as "outside".

pcb

Generating the rml files

To generate files for the milling machine you can follow this link: fabmodules.
Chose the upper settings.
For the settings on the right you have to choose specific settings for your milling machine.
In my case I used the MDX-40.
Following settings should be changed with the MDX-40 for the inside:

  1. X: 0 0
  2. Y: 0 0
  3. jog height: 5 mm
  4. cut depth: 0.0
  5. tool diameter: 0.2 mm
  6. offset overlap: 55%
Press calculate and save the rml file.

rml file

Repeat the steps above with your outside file.
Following settings should be changed with the MDX-40 for the cutout:

  1. X: 0 0
  2. Y: 0 0
  3. cut speed: 1 mm
  4. jog height: 5 mm
  5. cut depth: 1.9 mm
  6. tool diameter: 1 mm
  7. number of offsets: 1



Milling machine

I used the MDX-40 for the pcb board and as a material FR2 rubbed in alcohol.

milling machine

The material was stuck to wood to prevent damaging milling machine parts.

milling machine

After the machine was turned on we had to change the drill for the inside and outside.
Then we set the home position of the machine with a program.

The orange, red and green arrows are for the x and y positions.
The blue ones are for the z position.
To set the z origin set the drill to 15000 rpm and turn it on with the button under the rpm.
Now you can either try to hear when the drill touches the material or you can measure it with a multimeter.
Press apply when your position is right.

If you see that your z position is too deep or too high while the machine is drilling you can stop it and start a new job with a new z position.
In this case we can press the view button to check the milling. If we press it again for a few seconds the machine will continue the job.
Always vacuum the dust after opening the machine.

milling machine


The board

This is the board after solding the micro chip and drilling the holes for the pins.

pcb

Here is my finished board.

pcb pcb

Arduino IDE

To let the LED blink we have to program it. This happens with the help of the Arduino IDE.

  1. Connect the arduino uno to the pc
  2. Select the right port and the arduino uno board under tools
  3. Under file > examples find and open the arduino as isp sketch
  4. Upload the sketch to the arduino
  5. Disconnect the arduino from the pc

  6. Connect the hello board with the arduino
  7. pcb
  8. Connect the arduino to the pc
  9. Select the right board/processor/frequency -> attiny25/45/85, attiny45, internal 8mhz
    If you cannot find the attiny follow these steps:

    Go to file > preferences and paste the following link in the URL field.
    https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json
    Open Tools > Board > Boards Manager
    Type in "attiny", select and install it.
    Now you should be able to select the attiny.
  10. Under tools select the arduino as isp programmer
  11. Click to tools > burn bootloader
  12. Go to file > examples > basics > blink or write your own program
  13. Replace the variables. In my case the "LED_BUILTIN" should be "2"
  14. To program the board do sketch > upload using programmer

The pcb and program works!

pcb


Downloadfiles

  1. inside.rml
  2. outside.rml
  3. hello.brd
  4. hello.sch
  5. arduino_connection.png
  6. eagle_pinout.jpeg