The CNC 3018 I got comes with some fine tipped bits, they are cheap, and sharp..,
They are indeed pointy. If you try milling, they break, as they seem to in a slight breeze. They may have uses for wood or something, but for PCB they do not.
Broken bitEven broken, they have some use, but the width depends on where they broke. And you have to start the cut again once it breaks. Bugger.
Flat end millYou can get flat end mill bits...
These are not bad, but as you can see, the end is quite long. This is a 0.5mm diameter bit, which is still quite chunky, but it can cut the copper off a board.
The problem is they snap, and do so easily. It is a tad obvious from the design. So not so good.
What they do work really well for is drilling a hole and moving around to make a larger hole. All of the holes I make are done with this 0.5mm bit.
Bigger bitI also have a 1mm version...
This is something I use for cutting the PCB outline. Works well.
Cutting the board.What I found works well is a wider bit...
The issue here is depth control. At 45 degrees it means cutting down an extra 0.05mm means an extra 0.1mm width.
The trick is Z axis levelling, which bCNC can do. I added to my CNC 3018...
I initially tried to connect the wires to "Z" on the controller, but missed and was connected to next pins which are "A5", but it seems they worked and "Z" (I assumed Z end stop) did not work. The bCNC code just worked (with "A5"), and did auto levelling. Wow.
End result is I can cut tracks between 0.1" pitch pins!
I have been getting good at single sided designs with no links, but this makes it that bit easier.
P.S. Designs and code on GitHub... @aaisp giving back to open source.
It is funny how old-school lead(+silver) solder is easier to use...