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Week 8

Week 8 – Electronics Production

For Week 8 I focus on the full production workflow: toolpath generation, milling, stuffing, debugging, and programming.

1. Tool Preparation and Machine Setup

To manufacture the PCB, I used a CNC milling machine (SRM-20). The production required several specific tools and materials, including a copper-clad board (textolite), milling bits, and machine accessories.

First, I fixed the PCB material onto the machine bed using double-sided tape. This is a simple but effective method to keep the board stable during milling. The surface of the machine bed was already leveled, so I only needed to correctly set the Z-axis. I adjusted the milling bit until it just touched the copper surface, verifying contact using a multimeter.

During the process, I changed the milling bit twice, depending on the operation (traces and outline). The full setup and milling process took around 2 hours.

2. Toolpath Generation and File Preparation

In KiCad 9.0, I opened the PCB editor and prepared the design files for manufacturing. I exported the Gerber files (.gbr) without changing the layer settings, since everything was already configured during the design phase in Week 6.

Next, I generated the drill files and saved the report. After exporting, I had a complete set of Gerber files.

To convert these files into a format suitable for milling, I used an online tool called Gerber2PNG. Initially, I encountered an error: the files were not converting correctly. After troubleshooting, I realized that I had forgotten to include the “Edge.Cuts” layer in my PCB design. After adding this layer and re-exporting the Gerber files, the conversion worked perfectly.

I initially generated three PNG files and transferred them to another computer via Telegram, where the SRM-20 control software (VPanel) and ModsProject were installed. However, this approach did not work successfully. The main issue was that during file transfer or export, the PNG files lost correct scaling and resolution settings, which caused incorrect toolpath generation in ModsProject. As a result, the milling process could not be completed properly.

For the second attempt, I changed my workflow. Instead of sending PNG files, I transferred the original Gerber files to the second computer. On that machine, I converted the Gerber files into PNG format locally. This ensured that the resolution, scaling, and layer settings were correct and consistent.

After that, I loaded the newly generated PNG files into ModsProject, created the toolpaths, and sent the G-code to the SRM-20 machine. This time, the milling process was completed successfully without errors.

This experience showed that it is more reliable to transfer original Gerber files and perform conversion on the same computer where toolpath generation is done, to avoid compatibility and scaling issues.

In ModsProject:

  • I loaded the PNG files
  • Set the tool parameters using a V-bit calculator
  • Configured the tool diameter to 0.1 mm
  • Generated toolpaths using the “mill raster 2D” process
  • Exported the G-code

Then, in VPanel SRM-20 software, I uploaded the generated file and started the milling process.

3. Milling Process

The milling process was successful on the first attempt without any major issues. I obtained a clean PCB board with accurate traces and outlines.

4. Stuffing and Soldering

After milling, I proceeded to assemble (stuff) the PCB. I used the KiCad schematic as a visual reference during soldering.

The components I used include:

  • ESP-12E module
  • Pin headers (2.54 mm)
  • Resistors (1206)
  • LEDs (1206)
  • SMA diodes
  • Relay (Sanui)
  • Push buttons (6 mm)

For soldering, I used a soldering iron, hot air heater, solder wire, flux, and supporting tools. The soldering process took about 2 hours and was completed without major issues.

5. Reflection and Improvements

Overall, the workflow was successful, but there are areas for improvement:

  • Always include the Edge.Cuts layer before exporting Gerber files
  • Double-check files before converting to avoid time loss
  • Optimize milling parameters to reduce production time
  • Improve soldering speed and accuracy for complex boards

This experience helped me better understand the full PCB production cycle, from design to a functional electronic device.