You first need a test bar to suit the bed length of your lathe. I have two Indian made ones, both with MT2 at one end, one has about 5" and the other 9" of parallel length. Both have centres in their ends. I chucked up a piece of steel about 10mm diameter in the chuck and turned a 60 degree point on it. It must not be removed from the chuck (or collet) until after the alignment is complete, and if it is re used at a later date, it must have the tip recut before testing. Put the bar in between the temporary centre and a dead centre in the tailstock and run a dti fixed to the saddle along the plain part of the bar and adjust the tailstock sideways until it is exactly in line with the axis of the lathe. The height can also be checked with the dti on top of the bar. This is not so easy to adjust, and won't be a problem if it proves to be one about 0.07mm or 0.003" high at the right end.
These test bars come in MT1 upwards to suit all sizes of lathe. I bought mine on ebay, and they are better than I can measure.
You can also put the MT end in the tailstock to check that the quill is lined up.
I wonder if the headstock would have to be moved if the tailstock is fixed? You still need to know whether the tailstock quill is in line with the bed axis first in this case.
Edited By old mart on 10/11/2019 18:22:07