Hobby CNC mills have made rapid prototyping easier and faster for hackers. One really useful application is quickly fabricating your own milled PCB’s. [proto logical] built a Reference PCB Business Card using his CNC mill after repeatedly coming across other hackers who were not too convinced about the capabilities of CNC mills in routing PCB’s (also referred to as isolation milling). He thought of making a business card sized reference PCB to show around when he bumps into such folks.
To keep it useful, he included inch and centimetre scales, 0.1″ grid of holes, reference track widths from 16 mil to 66 mil, a few common drill holes and vias and some SMD foot prints. The single sided board is 50 mil thick, so it doesn’t bulk up his wallet. He’s posted the Eagle board file (direct download) and G-code (text file) for those interested in milling their own reference boards. The idea isn’t new – it’s been tried several times in different form factors in the past, generally using more traditional techniques. [proto logical] got inspiration from [Rohit Gupta’s] TinkerRule – The Maker’s Swiss Army Knife. Then there’s the very popular uRuler made by [Dave Jones] of EEVBlog fame. If you have any suggestions on improving the design, chime in with comments here.
Thanks to [ACG] for sending in this tip that he dug up while looking for CNC routed PCB’s.






[Wilfred] was testing a titanium 3D printer at work and was looking for something to print. The skull ‘n wrenches was a suitable candidate, and the results are fantastic. From [Wilfred]: “Just out of the printer the logo looks amazing because it isn’t oxidized yet (inside the printer is an Argon atmosphere) Then the logo moves to an oven to anneal the stress made by the laser. But then it gets brown and ugly. After sandblasting we get a lovely bluish color as you can see in the last picture.”