QTB Spindle Alignment Help...
Make a test cut but........
Wouldn't make sense to take a piece of round stock reasonably precision, put it in the spindle and check for runout.
Mounting an indicator on the cross slide and check the top of the "test bar" at the spindle face. Rotate the spindle and equalize the runout over zero, move to the end of the bar and find the high spot with the cross slide and rotate the spindle. The runout should be still centered over zero. If the runout is not centered over zero, the head stock needs to be leveled.
This can be done any number of times and your "test bar" is still in good shape (No smaller)
Then move the indicator to the front of the "test bar" (Where you would be normally be cutting and equalize the runour over zero. Then move to the far end of the bar and rotate the spindle and see where the indicator shows the runout to be. If it is centered over zero, the head is square, Centerline to the Z axis rails.
This check can be made a hundred times and the "test bar" will not change.
I guess this is the basic difference twix lathe guys and milling machine guys.
Use a known bar in the spindle and bring the head around to make it right.
Regards Walt...