There have been several types of spindles developed to
mount tooling (chucks and faceplates) onto them. The
earliest was the threaded type. This type is straight
forward but has the disadvantage in that it can un-thread
if the spindle is rotated in the reverse direction.
To address this problem, there have been some different
spindle mounting systems, Type D - Camlock, Type A1 -
Short Taper, Type A2 - Short Taper and Type L - Long Taper.
Type D - Camlock seems to be the most popular of these
different types. In my case, I own a couple other lathes
that have the Type L - Long Taper spindles. In each type,
there are different sizes starting with L00 and go up to L3.
The chuck is drawn onto a large taper that centers the chuck
on the spindle and there is a longitudinal key that prevents the
chuck from slipping while on the spindle. This allows the spindle
to turn in either direction without the risk of the chuck coming