Week 8 Electronics production

This week, I finally completed the processing and manufacturing of the circuit board. It wasn’t easy — there were delays and technical issues — but I didn’t give up. In the end, it felt incredibly rewarding. This whole journey proved that perseverance really pays off.

Learning Objectives

• Group assignment:

  • Complete your lab's safety training
  • Characterize the design rules for your in-house PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline) and tooling
  • Document the workflow for sending a PCB to a boardhouse

• Individual assignment:

  • Described the process of tool-path generation, milling, stuffing, de-bugging and programming
  • Demonstrate correct workflows and identify areas for improvement if required

  Learning highlights

  production

  

  Electronic design

  Schematic & PCB

  

Group Assignment

1.1 CNC Milling Machine

The CNC Milling Machine is a computer-controlled device that precisely cuts and shapes materials. "CNC" stands for "Computer Numerical Control," allowing accurate control over tool movement, speed, and cutting depth via digital codes.

1.2 Roland MDX-40A

The Roland MDX-40A is a desktop CNC milling machine suitable for model making, prototyping, and precision PCB fabrication. It is known for its ease of use and accuracy, ideal for educational and maker settings.

Main Features:

Feature	Description
Work area	305 mm x 305 mm x 105 mm
Spindle speed	Adjustable for different materials (plastic, wax, wood, FR-1 PCB, etc.)
Compatible software	Roland VPanel (control), Mods CE (PCB path generation)
Supported tools	1/64 inch (0.4 mm) and 1/32 inch (0.8 mm) end mills

1.3 Preparation Process

• Clean the machine and workspace

• Clean the FR1 PCB, then apply a smooth layer of double-sided tape.

• Stick double-sided tape on the back of FR1-PCB and fix it onto the MDF base

• Open Mods CE, right-click to access “Programs,” then select Machines > Roland > MDX mill

• Test image in PNG format

• Import test image into Mods, set DPI to 1000, and verify dimensions

• Choose milling type and set cut depth: 0.1 mm for traces (1/64), 1.8287 mm for outlines (1/32)

• Select MDX-40, set the origin to (0,0),intput-outpot

• Click "calculate" to generate tool paths

• Generate tool paths

• Export RML files and transfer to Roland VPanel via USB
LinTest the 0.4 mm toolpath. LineTest interior the 0.8 mm toolpath.
• Use correct tool size (0.4 mm or 0.8 mm);secure the bit clockwise with wrench

• Move X/Y to desired origin and click "Set XY",Calibrate Z-axis using the tool sensor and clean sensor surface.

• Set spindle speeds: 9500 RPM for 0.4 mm, 11000 RPM for 0.8 mm

• Cut traces first, then outlines to prevent shifting

1.4 Summary

• Ensure workpiece is firmly fixed to avoid shifting
• Choose proper tool and cutting parameters to avoid tool breakage or burning
• Set correct origin and offsets in Mods
• Adjust spindle speed to material and bit
• Dry run before cutting and monitor process during milling

Individual Assignment

2.1 Generate PNG File

• Open the PDF exported from JLCEDA in GIMP
0.4mm PCB 0.8mm PCB
• Set resolution to 1000 dpi for clarity

• Resize canvas using Image > Canvas Size; fill transparent areas

• Adjust layer size to match image size

• Create a white-filled transparent layer and place it underneath

• Export both layers as an uncompressed PNG file,Maximum image compression level

2.2 Generate Toolpath

• Use Mods to generate the cutting path from PNG

• Select: programs > open program > machines > Roland > MDX mill > PCB
• Upload PNG (1000 dpi), set cutting parameters for 0.4mm bit or 0.8mm bit

• Click "calculate" to generate tool paths

• Enable saving tool path to file
0.4mm PCB 0.8mm PCB

2.3 Milling

Use Roland MDX-40A and VPanel to upload toolpaths and begin cutting.

Finished PCB:

3.1 PCB Soldering

• Prepare soldering iron, components, and tools (use flat-head tip)


Quantity	Component	Description
1	Xiao ESP32-C3	Microcontroller module
1	1kΩ resistor	Standard resistor for current limiting
1	499Ω resistor	Standard resistor for LED or sensor use
1	Yellow LED	Light-emitting diode (yellow)
2	3-pin right-angle male header (SMD)	Surface-mounted horizontal pin headers
1	8-pin right-angle male header (SMD)	Surface-mounted horizontal pin header
1	Switch	Toggle or push-button switch

• Test Seed Xiao P32 board – indicator light should turn on.

• Fix the board with two pin solders first.

• Complete the soldering from top to bottom in order.

• Solder 1206-sized components using proper flux amount,Include resistors, indicator LEDs, and the switch..

• Finally, solder the pin headers (8P & 2×3P).Solder pin headers carefully – avoid long heating that can lift copper.

Completion and testing

Notes:

• Keep soldering iron tips clean.
• Use flux moderately.
• Avoid overheating components.

3.2 Testing

Use Arduino Uno as a programmer for Seed Xiao

• Open Arduino IDE > File > Examples > select Xiao ESP
• Upload code to Arduino Uno to control the board

• Perform LED light test: control the yellow and green LEDs to blink repeatedly for testing.