Machinist

[Lawrence London <lfljvenaura@gmail.com>]

http://www.practicalmachinist.com/vb/south-bend-lathes/chuck-mounted-tool-post-power-feed-drilling-187381/

to  line up the drill on the center put a dead center in the lathe chuck
 and drill chuck, and then line them up.   (first make sure your tool 
post is perfectly parallel to bed)
				

an effective way to get two sharp 
centres lined up to within surprisingly close limits is to lightly pinch
 a 1/2" wide 6" rule (or similar size and weight of steel strip) between
 the points. 
 When it lies straight up and down and straight across the 
bed the points are lined up.  With sharp points and good eyeballing the 
error is in single digit tho