Week 8 Electronics Production

This week, my individual task was to produce a PCB using a carvera milling machine.

Mr. Dubick created a simple board in Kicad and gave us the gerber files. I also got a super helpful and detailed workflow for using the carvera machines. Here is the link to the slideshow.

Process and Settings

Above are the gerbers given by Mr. Dubick after being imported into MakeraCAM.

Axis

The Makera machine I used is 3 axis, when first opening the MakeraCAM app, I selected 3 Axis.

Material Setup

The PCB Material I used was 127mm by 101mm and 1.7mm thick. On the left window, I changed the stock settings to the size of my PCB material.

Importing the Gerbers

At the top, I imported all 2 files, the edge cut gerbers and the front copper gerbers. I imported them one at a time using the import PCB tool.

Note: If your PCB has through holes, you will need drill files, seperate from gerbers.

Moving the PCB to the correct spot

Once all gerbers were imported, I selected the anchor point at the bottom left of the PCB. After that, I set the X and Y location both to 6mm. This accounts for the bracket we use when milling PCBs on the Carvera machine.

Toolpaths

When a vector is selected, it will appear as a dotted line. When generating a toolpath, the toolpath will only generate for the dotted line vectors.

Edge Cuts - I used the 2D contour tool path. I selected the 8mm corn bit, and outside toolpath. Finally, I set the cut depth to 1.7mm and added tabs, so when my pcb is cut, it stays in place. After that, I calculated the toolpath.

Traces - I used the 2D pocket tool path. I used the 8mm corn bit and the 0.2mm 30 degree engraving bit for precision. The software calculates where to use the 8mm corn bit and the 0.2mm bit. I set the cut depth to 0.05mm, just enough so it cuts the copper layer without cutting the actual PCB. I selcted the traces and the outside rectangle so the toolpath cuts the pcb around the material around the traces.

After this, the toolpaths are created and able to be saved as gcode files and sent to the machine.

Tool Settings

Below are the settings for each tool used, the 8mm corn bit and the 0.2mm bit.

8mm Corn Bit:

0.2mm 30 degree Engraving (Metal)

Native File

By clicking below, you can download my native file.

Click Here to Download the File

Milling

I put nito tape on the backside of the PCB material, then used brackets to hold the pcb in place.

MakeraController

This is the software we use to control the milling machine. It is very simple, all I did was upload the gcode, then press run. The machine autoleveled the bed, automatically changed the tool to the correct tool, and then started the job.

This is my board after milling, everything turned out correct. The traces came out very small, but there is still copper and they should work.

I soldered on 3 components, a Xiao ESP32, an SMD resistor, and an SMD LED. I used SMD headers to attach the ESP32 to board.

I used a simple blink code to blink the LED in the video.

Code

I asked ChatGPT to generate me code to blink pin D7 on the xiao esp32c6 in C++, it gave me:

#define LED_PIN 17   // D7 = GPIO17

void setup() {
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_PIN, HIGH); // LED ON
  delay(500);
  digitalWrite(LED_PIN, LOW);  // LED OFF
  delay(500);
}

Link to Group Project

Click Here to go to the Group Project

My contribution was the characterizing design rules. I did the line test to see how precise the 0.2mm 90 degree bit is (Most used for milling traces).

Reflection

This week was cut in half, before I left for spring break, I finished milling this board I documented above. When I got back, I forgot where I leftoff and started the line test on the group project. I had to go back and document week I did over a week before, while documenting for the group project which got confusing. I switched up some files, but got everything in order eventually. Overall, this week is not too demanding, the hard part for me was a week long break halfway through the week.