Angle grinder sander for slots and grooves

[Crusty]

It's a common oversight here Frank that things which spin at 12,000 rpm aren't given any evaluation of the significant effects of rotational dynamics. Seemingly strong things explosively fly apart when spun fast and unbalanced.

For instance a 5" diameter by 1/2" thick balanced birch plywood disc rotating at 12,000 rpm has a total force of greater than 3500 Newtons acting on it. That's a lot.

I wouldn't stand within 25' of that thing in motion.