08

Electronics Production

Week 8 · 🔧 PCB milling & soldering

📋 Assignment Overview

⚡ Week 8 documents Electronics Production: fabricating a PCB, soldering, and testing. Below is the workflow from design export through production.

📋 Assignment Process

🖥️ Software used

Pre-export: Autodesk Fusion 360

Machining (Windows lab PC): Roland MDX-40 Panel, ModelA Player 4

Fusion 360 download: https://www.autodesk.com/products/fusion-360/overview

ModelA Player 4 download: https://www.rolanddga.com/support/products/software/modela-player-4 — official Roland DGA page for the Modela Player 4 installer and updater.

Steps below: Pre-export (Fusion) · Machining (Panel + CAM).

📤 Step 1: Copper layer only — export STEP

After finishing the 3D PCB output, remove the other unnecessary bodies and keep only the copper layer, then export in STEP format.

Fusion 360 — 3D PCB export, copper layer retained for STEP
After 3D PCB output: strip extra geometry, keep copper layer, export STEP
Fusion 360 — copper layer and STEP export
Copper layer only, ready for STEP export

📐 Step 2: Create a face at the top level

At the top level of the design, create a new face (construction surface or sketch plane) as shown.

Fusion 360 — create face at top level
Create a face at the top level

✏️ Step 3: Sketch on the face — level the surface

Create a sketch on that face, then run a facing operation to remove one layer so the top stays flat with no steps or ridges.

Fusion 360 — sketch on face and facing to level the surface
Sketch on the face, then face the stock to a flat top

📦 Step 4: Export STL

After facing, export STL from Fusion and set mesh resolution / units as needed.

Fusion 360 — STL export
STL export from Fusion

🔌 Step 1: Power on, View, and align the tool

After switching the machine on, click View, then open Roland MDX-40 Panel. Use the software to jog the drill to the top-left corner of the prepared copper board.

Roland MDX-40 — View and machine ready
Machine on: use View and Roland MDX-40 Panel to prepare for alignment
Roland MDX-40 Panel — drill aligned to board top-left
MDX-40 Panel: position the drill over the top-left corner of the copper board

⬇️ Step 2: Spindle on and touch off Z

In the same panel, start spindle rotation, then adjust Z until the bit lightly touches the copper—just a kiss, not deep—to avoid snapping the tool.

Roland MDX-40 Panel — spindle and Z touch-off
Enable rotation; lower Z until light contact with the board (avoid excessive depth)

🗂️ Step 3: Machining sequence

From this step on, switch to ModelA Player 4 for CAM and the screenshots below (after setup in Roland MDX-40 Panel in Steps 1–2). Click any thumbnail to view full size. Use the on-screen arrows or keyboard ← / → to move between images. Press Esc to close.

Change view and check thickness

Change the view and verify model thickness.

Model size and orientation

Set → Model size and orientation; rotate 90°.

Origin top-left

Origin: click the top-left corner as the cut start.

New process

Click New process on the right.

Finishing

Choose Finishing.

Tool definition

Select your prepared tool / bit data.

Contour lines

Select Contour lines.

Contour options

Enable both options below.

▶️ Step 4: Preview toolpath and start cutting

Click Preview in the bottom-right corner to check that the toolpath looks correct. If everything is OK, click Cut (or the equivalent start command) to run the job.

CAM preview and cut — bottom-right controls
Preview the path, then confirm and cut

🎬 Step 5: Cutting process

Recording of the machine running the cut, and the milled board after the job is finished.

Cutting process
PCB after milling — finished appearance
Finished board after machining

🔧 PCB design iterations — three revisions compared

The first milled board failed due to pad and connectivity issues. The table below compares three revisions (V1 → V2 → V3): what went wrong, supporting images, and what we changed each time. The pad issue is resolved in V3; final CAD files are in Week 6 — Final PCB Design (Revision V3).

Revision Problem Images Solution / next step
V1 — First prototype
Initial milled board

Design Rules (DRC) were misconfigured in Fusion 360. Solder pads were omitted or too weak in the CAM output, causing intermittent connections and poor solder joints.

During servo/LED testing, an overcurrent condition damaged the XIAO ESP32-C3.

Separately, firmware upload failed: sketch compiled, but esptool reported No serial data received (bootloader/port or damaged module).

esptool v5.1.0
A fatal error occurred: Failed to connect to ESP32-C3: No serial data received.
First milled PCB — finished appearance before failure analysis
First milled board (before rework)
Arduino IDE — compile OK, esptool upload failed
Upload failed — no serial from ESP32-C3
  • Document failure and trace root cause to DRC / pad generation.
  • Plan a board revision with corrected rules before re-milling.
V2 — DRC-only fix
Attempted revision

Updated Design Rules (DRC) and re-exported the layout. This improved some settings but did not fully solve assembly: pads remained marginal for hand soldering on a single-sided milled board, and mechanical connection was still unreliable.
Fusion 360 — revised DRC and board layout (V2)
Revised layout & rules (1)
Fusion 360 — Design Rules dialog (V2)
Design Rules dialog (2)
  • Correct clearance, track width, and pad rules in Fusion electronics.
  • Re-check CAM export — insufficient alone; proceed to footprint change (V3).
V3 — Pin headers
Final (resolved)

Small or omitted pads on milled copper were hard to solder and debug. Needed larger, repeatable connection points for modules and wires.
Revision V3 — final assembled PCB with pin headers
Final assembled board (V3)
  • In the electronics sketch, replaced connector pins with pin header footprints.
  • Through-hole pads for 2.54 mm headers; solder headers first, then plug modules.
  • CAD: Week 6 — schematic & 2D layout (V3).

Status: resolved (V3)