Hi,
amongst the things I do with my mill is make circuit boards. Through hole boards I do with 0.5mm Kyocera Tycom two flute endmills, surface mount boards for which I require 0.2mm
and less between traces I use 450 engraving tools.
What I can tell you is that tools of this description require a superb spindle, 24000 rpm min, 36000 is better and 60000 is better again but IT MUST HAVE VERY LOW
runout otherwise you'll be very disappointed.
I use a 800W air cooled spindle from Mechatron GMBH, and have used it for seven years. It cost me $1000NZD, about $690USD. There are plenty of Chinese spindles of similar
specs and much cheaper....say $300, but the point is that your budget is looking a little thin for the kind of performance that you want.
I use Mach4 Hobby ($200USD), an Ethernet SmoothStepper ($200USD), a homemade own design breakout board ($200USD), a Delta 750W VFD ($300USD)....and the list
goes on.
What CNC software and motion controller did you have in mind?
When you say very precise...what do you mean? Within 0.1mm? Within 0.01mm? Within 0.001mm? Each time you go 'up a level' the cost increases a hundredfold, so be very considered
about want you 'need' as compared to what you 'want'. What you 'want' is likely to be so far outside your budget its not funny. I have exactly the same problem!
Craig