One day I was having a new tip put on and he grabbed the 12.5 mm collet and when he slid it on the shaft about 3" from the ferule it actually rattled and wouldn't hold tight.

If that wasn't bad enough, he was using a Porper lathe where a fair amount of the joint end of the shaft sticks out of the head and it was bouncing so bad he had to ask me to loosely hold onto it to keep it from oscillating too much because of chatter on the other end