I hate these things, i get very nervous on them due to the lack of suitable safety guards.
Several months ago a bloke at my work had a 2 kilo steel casting fly out the jaws on the capstan he was on and it hit him square in the face. Knocked 17 of his teeth out and broke his nose and jaw.
He was off for 17 weeks and had to have facial reconstruction
I wish it wouldn't crash.