Hello Gentelmans,

Some older lathes doesn't have an angle scale on a toolpost. It is
possible to adjust the toolpost via laser pointer with or without
colimating lens and some linear scale on e.g. spindle.

Here's my document with calculation of residual systematic error.
Suprisingly it is possible without much effort to get 1/6 deg
accuracy. I couldn't find any error in calculus.

http://tinyurl.com/6ntza
http://tinyurl.com/55rhx

Comments and corrections appreciated --Jack.