Quote Originally Posted by John11668 View Post
I did similar when grinding accross my Sine bar.
Except mine bit a sizable chunk out of the wheel and got the machine running frighteningly out of balance .
I hit the E stop but it had to run down through a resonance band , Got much worse before it got better.
We did it with the motor off. Then switched it on when we casually walked past.

I have heard that the trick in school and college engineering shops is to set the lathe on autofeed to self destruction. At my school the lathes had autofeed disabled and that was 55 years ago.