I'm making a project, but my arduino pro micro is just slightly too big to fit in it's case.
What would happen if I cut off the pin holes that I don't need? Would it still work? Or would it be ruined?
Arduino Stack Exchange is a question and answer site for developers of open-source hardware and software that is compatible with Arduino. It only takes a minute to sign up.Sign up to join this community
I guess that one could cut (or hone down) parts of the PCB. Obviosly this process devoids the warranty and there is the risk of damaging either the board or some components on it (i.e. by holding or clamping it during the process).
I would not expect any other wiring besides those connecting the pins to run in this part of the PCB. The reference layout (see board layout and using Eagle (free version)) - if the clones follow that layout - confirms that there are no other traces there. So it is mostly important to not cut any other traces and remove any chippings after the cutting to avoid short circuits.
If in doubt buy two or three boards ;) to try and repeat the process.
This is a bad ideas:
the PCB is made of fiber glass which, when broken, cut or filed, produces a very fine powder; any powder you might breath in during the process wil stay in lungs for a very long time, in the order of decades
the risk of cracking traces running close to the are of cut, even if they are not directly being cut, is pretty high; the copper traces rely on the fiberglass rigidity, but a crack in the fiberglass propagating under the traces is welcoming a broken trace
Go for a different case, if that's not a viable option go for a barebone arduino. If that is also a non viable option consider the idea of producing a few custom PCBs: they are not that expensive!