8. Electronic Production - Students¶
Carvera PCB Milling Workflow — Oliver Abbott¶
This documents the complete MakerCAM workflow for milling a PCB on the Carvera CNC mill. The process involves setting up the stock material, importing KiCad design files, generating three separate toolpaths (traces, drill holes, and board outline), then simulating and exporting the G-code.
Setup¶
1. New Project¶
Open MakerCAM → New Project → Select 3 AXIS
2. Stock Material¶
Stock Setup → Edit with the following values:
| Parameter | Value |
|---|---|
| Material | PCB |
| Length (X) | 127 mm |
| Width (Y) | 101 mm |
| Height (Z) | 1.7 mm |
3. Import PCB Files¶
File → Import → Import PCB (KiCad Gerber & Drill)
Import these three files:
| File | Purpose |
|---|---|
| Edge_Cuts | Board outline |
| F.Cu | Copper traces |
| PTH.drl | Drill holes |
4. Position the Design¶
- Zoom out and drag-select the entire design (dotted lines appear)
- Press M to open the Move tool
- Set Anchor to lower-left corner
- Set Location X: 6.000, Location Y: 6.000
- Click Close
Toolpaths¶
The PCB requires three toolpaths, run in this order:
Toolpath 1 — Trace Isolation (2D Pocket)¶
Removes copper around the circuit traces to electrically isolate them.
| Setting | Value |
|---|---|
| Tool | 2D Pocket |
| Start Depth | 0.000 mm |
| End Depth | 0.05 mm |
| Tool 1 | 0.8 mm Corn (listed first) |
| Tool 2 | 0.2 mm 30° Engraving (Metal) |
| Path Strategy | Parallel |
Selection: Show only F.Cu and Edge_Cuts layers. Select both, then click the outermost outline to deselect it — only the traces and inner outline should remain selected (dotted). Click Calculate.
⚠️ The 0.8 mm bit must be listed before the engraving bit.
Toolpath 2 — Drill Holes (2D Drilling)¶
Drills the component through-holes.
| Setting | Value |
|---|---|
| Tool | 2D Drilling |
| Drill Tip Start | 0.000 mm |
| Drill Tip End | 1.7 mm (full board thickness) |
| Tool | 0.8 mm Corn |
Visibility: Hide everything except the PTH.drl layer. Select all visible drill holes. Click Calculate.
Toolpath 3 — Board Outline (2D Contour)¶
Cuts the board out from the stock material.
| Setting | Value |
|---|---|
| Tool | 2D Contour |
| Start Depth | 0.000 mm |
| End Depth | 1.7 mm |
| Tool | 0.8 mm Corn |
| Strategy | Outside |
Visibility: Hide everything except the Edge_Cuts layer. Select the outline, then click the outside line to deselect it (turns solid) — the inside line must remain dotted. Click Calculate.
Tabs: Scroll to Tabs → Select Custom → Click Add → Place 3–4 tabs around the board outline. These hold the board in place during the final cut.
Simulate & Export¶
- Click Preview Toolpaths
- Check all three: Pocket, Drilling, and Contour
- Click Preview and verify the simulation looks correct
- Close the preview → Click Export → Select all three toolpaths → Export
- Save the
.ncG-code file
Full Workflow Reference¶
Download the complete MakerCAM workflow with screenshots: MakerCAM Workflow PDF
PCBWAY - Max Negrin¶
Firstly, you have to zip up your GBR files you exported from Kicad. PCBWAY only accepts .zip or .7z files:
Then, it will autodetect the size of the board and the number of layers
And then you can select from the different settings to customize your PCB:
And even more settings:
You can find a detailed explanation of each setting in this pdf.
If you have a large number of SMD components, they have the option to order a custom stencil using your GBR files:
You overlay this stencil onto your board, and line up the stencils holes with your PCB’s pads. Then, lay solder paste along the entire stencil, pushing extra paste into the gaps using a card. When you lift the stencil, there should be solder paste over every pad, eliminating the need to individually place solder paste or normal solder on every pad.
Finally, you place your order an input your payment information:
And your PCB should arrive in a few days.
Characteristics - Line Test¶
The line test is a way to test the precision of our milling bits. Dr. Gershenfeld gave us an image of the line test. I converted the image to an SVG then imported it into MakeraCAM to generate the Gcode. I used a pocket cut and the 0.2mm 90 degree engraving bit because it is very precise.
This is the image Dr. Gershenfeld gave us.
This is the toolpath generated in MakeraCAM. The path is very fine becuse the tool is very precise.
Settings
Below are the settings I used with the tool
Milling
Milling took around an hour in total because of the lengthy toolpath, however I was expecting more. The gcode was over 40,000 lines long.
The tool did an excellent job cutting the outside of the lines, this proves good runout on the tool. The tool struggles with the inside lines. Also, two of the tests became conjoined which could have been caused by the PNG to SVG converter. The test is very small, in fact only around 12mm tall. The tool did a great job with the numbers, they are very precise at such a small scale.
Native Design File
Click Here to download the file
Reflection¶
The group assignment for this week was not to lengthy or difficult. We had previous experience using the Carvera milling machines from Pre-Fab work. Sending a board to a boardhouse was new, but the website made the process straightforward. The linetest was very nice because we didn’t have to design anything. Mr. Dubick and Dr. Taylor gave us a very helpful presentation on the MakeraCAM workflow which helped us with using the software.