I have inherited a lathe and am trying to learn a bit more about it. Its a delta 46-255 and there is no manual to be found on the internet anywhere! I have attached an image which shows some parts that I can't identify, hopefully I have attached it right. Is number 1 for securing the headstock angle? Number 2 is a plastic cap with a recess beneath it into the headstock and number 3 is a black knob that doesn't appear to do anything. Can anyone help shed some light on these parts?