By Their Powers Combined, a CNC Mill and a Fiber Laser Give Mikey Sklar Crisp, Clean DIY PCBs
Using the right tool for the right job is demonstrated to perfectly in this project.
Maker Mikey Sklar has been experimenting with DIY printed circuit boards ā but rather than the usual toner transfer and etch approach, has put two other tools to work: a CNC mill and a fiber laser, each making up for where the other lacks.
"You can make multiple custom circuit boards in under an hour using a CNC [mill] and a fiber laser," Sklar explains. "A CNC is ideal for making precise, deep cuts and drilling holes. We can use a 50-cent blank PCB and cut out three small circuit boards in less than nine minutes. While a fiber laser is capable of these tasks, it is better suited for delicate operations like trace cutting and engraving."
For the lucky maker who has both a CNC mill and a fiber laser available ā in Sklar's case the latter is an xTool F1 Ultra 20W fiber laser, while the former is any mill large enough to accommodate the blank PCB ā it's possible to rapidly create custom PCBs by using the right tool for the job. Cutting the PCBs with the laser would take far too long and generate excessive fumes; carefully cutting neat traces would be a real challenge for the CNC mill.
Sklar's approach uses both for what they're good at: the CNC mill is used to cut a larger blank PCB into three smaller boards and drill the mounting holes; the boards are then passed across to the laser to etch the traces. "The initial trace cut process is very fast," Sklar notes, "taking only 90 seconds to cut through the copper layer for all three boards. It reduces the relatively long engraving time, which was 34 minutes for all three boards."
The laser can then also be used to cut a thin layer of brass into a stencil, ready to apply solder paste to the boards ā held in a handy 3D-printed jig, just to add another tool to the mix. The boards are then ready for component fit and reflow to finalize their assembly into compact chording keyboards.
More information on the project is available, alongside settings for the laser and a Python tool for mirroring a DXF file, on Sklar's GitHub repository.
