Quote Originally Posted by m_c View Post

If you were worried about damage, I'd put the risk of crush injuries on any reasonably sized/powered CNC, far higher than a spindle starting up when you've got your hands near it.
Probably right. Thinking about it, I've stalled my 2.2KW spindle by trying to push it too fast/deep through steel - with a 4mm cutter. That was at around 5K RPM - no torque worth talking about. A spanner on a spindle would easily hold it.