Will 7000rpm for spindle suffice for isolation milling / drilling / routing of PCB's?
I have 400W spindle, it used to run @ 9000rpm but its power supply(48VDC) blew off and now I'm running at 36VDC and its running at around 7000rpm.
I have heard that PCB drilling needs high rpms aronud 24K and above.

I have some 30deg V bits, a few end mills and som drill bits.
I plan to mill with the 30deg V and drill 0.8mm holes.

What problems can I expect with doing the above operations @ 7000rpm. Broken drill bits?
Would I need to modify the feed rate and plunge rate accordingly?

Any suggestions would be appreciated!
TIA