PCB Milling
In this project we milled copper PCB boards using the new milling machines in the fab lab.
Workflow (Design Phase)
Open new 3D project in MakeraCam
Set material to PCB: Edit→Material→PCB
Set dimensions
X = 127mm
Y = 101mm
Z = 1.7mm
Download files from Fab drive: (blue folder named Dubick)
Resistance1-F_Cu.gbr
Resistance1-PTH.drl
Resistance1-Edge_Cuts.gbr
Import each of these files in MakeraCAM:
File→Import PCB→Downloads→Resistance1-Edge_Cuts.gbr→Open
File→Import PCB→Downloads→Resistance1-PTH.drl→Open
File→Import PCB→Downloads→Resistance1-F_Cu.gbr→Open
Anchor lower left corner:
Select whole design (highlight over everything)
Click “m” key
Select lower left corner in “Anchor” diagram at the top of new pop up (in top right corner of screen)
Under “Location” in pop up, set X to 6 and Y to 6 (offsets design from very edge of material)
Design should have moved to align with axes given
Path:
Under “2D Layers” menu, hide (eye with red cross through):
Resistance1-F_Cu.gbr_pad
Resistance1-PTH.drl_0.900 mm
Resistance1-PTH.drl_1.400 mm
Select 2D Path (in tool bar)→2D Pocket
Select whole (visible) design
Set “End Depth” to .05mm
Add tool x2
8mm Corn
.2mm*30Engraving(Metal)
Calculate
Drilling holes:
2D Path→2D drilling
Under “2D Layers” menu, hide (eye with red cross through) all but file with holes to drill (
End Depth: 1.7mm
Add tool: 8mm Corn
Calculate
Outside cut:
2D Path→2D Contour
Under “2D Layers” menu, hide (eye with red cross through) all but file with outside cut (Resistance1-Edge_Cuts.gbr)
End Depth: 1.7mm
Strategy: Outside
Tabs: Custom
Tab Shape: Triangle
Select “Add”
Click 3 places on outer edge (spaced fairly evenly apart)
Add tool: 8mm Corn
Calculate
Path→Export→Export OR if you want to edit file on milling machine’s computer, File→Save As, save file in downloads with .mkc format (file-type)
Upload file to your folder in Fab google drive
Images from Mr. Dubicks “MakeraCam_Workflow_presentation-slides”
Link: Google Slide
Workflow (Milling Phase)
Installing material:
Slightly loosen (not remove) all bolts in machine bed except the 3 that are fully within the metal jig/holder (use screwdriver on right side of machine)
If copper board already on bed with design milled into bottom left corner, remove and reorient if possible or else replace
Orient PCB board on CNC machine so that your design will fit in bottom left corner (as it was displayed on Makera CAM)
Adjust rectangular metal holders near middle of bed (keep bolts where they are, slide and rotate rectangular piece) to be able to slide material under loosened bolts, and then do so
Move/rotate both rectangular metal back so that short end of rectangle with slot aligns with material (holding it down)
Screw all loosened bolts down fairly tightly (securing material, not overly tight)
Running file:
Download gcode.nc file from Fab google drive
Open Cavera Controller
Open file (top left corner) → Upload File → (should be in Downloads) select your gcode file (yourfilename.nc) → “Upload & Select”
Idle (top left) → COM Port ___ (some number)
Additional settings (top right dropdown) → Display Manual Controls → Home
Tool status → ensure Voltage>3.6V
Second most right option on bottom bar → select (check) auto vacuum + select (check) auto-levelling; select Run
Machine should touch down at 25 points on material and then file should run (whole design should be automatically milled)
Final Product
Reflection
After this process I realize that the majority of milling a PCB board is the design phase and ensuring everything is correct. The new milling machines have self-swapping tool abilities allowing the user to walk away from the machine once it is started. This accelerates the rate at which you can finish a project as you can now work on another component while your board is being milled. During this project many issues occured. First, during the design phase we were given incorrect dimensions for the copper board leading to setbacks when we tried to mill. When we realized that we needed to change the dimensions we tried to re open the file in the Makera cam software in order to edit the file. However, we kept recieving a “file opening error” message from the software. After sending the error code to AI we realized that we were not able to open the file due to the files format. In order to open and edit the file design in makera cam the file must be a .mks format. On the contrary, if you wish to open your file in the makera controller then the file must be in gcode.nc format.
To access the links to the final product click here: