Counterweight test bar for headstock alignment

[tonyfoale]

EDIT: I had an error in the algorithm that calculates the incremental deviation (the first method), that explain the difference with the result of the Uniformity load method. Though measurements still do not match theoretical calculations.

The lathe pictures indicate that you have a fairly small lathe in which case the lathe will be deflecting. That will affect the relationship twix theory and practice. That is a large and heavy bar for a small lathe. Free play in the bearings will also cause discrepencies with a heavy bar.