Just look and see what happened when this Z axis failed and plunged the plastic bodied spindle into the work and stalled the spindle.
Perhaps the lesson is to make sure the correctly rated fuse or circuit trip is always used for the spindle when machines are left operating unattended.

http://www.flickr.com/photos/29506322@N08/sets/72157620853267251/

Tweakie.

Hi Tweakie,

It's said looking at these pictures... Your machine has been seriously damaged and the spindle is scrapped

Was it a Mach fault?

Hope you get it fixed soon...

Daniel

Hi Daniel,

It wasn't my machine, fortunately.
It appears that it was a mechanical fault when the leadscrew nut broke free from it's mounting and allowed the Z axis to drop.

Tweakie.

Oh, misery

I've got my bases covered, my mill came with an overload cutout on the spindle contactor. Triggering this estops the whole thing and it slams to a stop with no power to spindle or drives. Shame this one didn't have such an arrangement.

 

Brett