The lathe is new to me, it is an older Clausing Colchester 13x36. It shows signs of moderate ware, it does not show signs of outright abuse. I am trying to assess its condition and how far out of spec it is. I have been struggleing with measuring horizontal spindle alignment vis e vi the ways, I believe I have found a method.
I took two sets of measurements with an 8 inch diameter face plate attached to the spindle.
The first set indicated the plate was square to the spindle. At 60 degree increments I measured run out from 1 1/2 inches to the far edge of the plate using an dial indicator attached to the cross slide. All 6 of the readings were essentially the same at about 3 thousands. The fact that they are all the same indicate the plate is square to the spindle. (This ignores any error between the ways and the cross slide. )
The second was a bit more complicated. I attached attached a right angle plate to the face plate with a clamp with the exposed surface vertical. I then affixed a dial indicator to the cross slide reading square to the exposed edge. The setup is such that if the ways were square to the face plate then moving the carrage on the ways should result in no change to the reading.
I took a series of 4 readings. I started with the indicator close to the face plate and moved the carrage out 3 1/2 inches. I then rotated the face plate 90 degrees, reattached the angle plate in the same relative position to the ways, and retook the measurement. In all 4 cases the readings were the same, they started out a 0 and moved to plus 3 thousands in 3 1/2 inches. Given that the face plate is square to the spindle I conclude the spindle is out of alignment with the ways by about .001 per inch.
(Unfortunately the head is machined to ride on the Way V's. )
I have been unable to detect measurable run out in the spindle. The runout of the surface of the face plate while rotating the plate is less that .001.
I took two sets of measurements with an 8 inch diameter face plate attached to the spindle.
The first set indicated the plate was square to the spindle. At 60 degree increments I measured run out from 1 1/2 inches to the far edge of the plate using an dial indicator attached to the cross slide. All 6 of the readings were essentially the same at about 3 thousands. The fact that they are all the same indicate the plate is square to the spindle. (This ignores any error between the ways and the cross slide. )
The second was a bit more complicated. I attached attached a right angle plate to the face plate with a clamp with the exposed surface vertical. I then affixed a dial indicator to the cross slide reading square to the exposed edge. The setup is such that if the ways were square to the face plate then moving the carrage on the ways should result in no change to the reading.
I took a series of 4 readings. I started with the indicator close to the face plate and moved the carrage out 3 1/2 inches. I then rotated the face plate 90 degrees, reattached the angle plate in the same relative position to the ways, and retook the measurement. In all 4 cases the readings were the same, they started out a 0 and moved to plus 3 thousands in 3 1/2 inches. Given that the face plate is square to the spindle I conclude the spindle is out of alignment with the ways by about .001 per inch.
(Unfortunately the head is machined to ride on the Way V's. )
I have been unable to detect measurable run out in the spindle. The runout of the surface of the face plate while rotating the plate is less that .001.