Error 1 turning point from a spindle axis cause and elimination methods (with the ball inside the car as an example).
As shown in Figure 1, the y for turning tools deviate from the X axis distance, DT theory of A-A section diameter, D is the diameter of ball, R=D/2 for CNC lathe tool circular interpolation radius. On the A-A section cutter circular interpolation curve is long axis for the d axis and the short axis of the D1 class of elliptic, the error is d=D-D1=D-2[(D / 2) 2 - the Y2] (1)
In actual production, the product drawings are generally put forward to be processed ball diameter precision. Such as the precision of ball bearing precision is generally within the + + d=0.01mm, that is, 0.005mm. In order to ensure the accuracy, the Y must be controlled. By formula (1) as the Y= + (2Dd-d2) integrant integrant
D=80mm, in the processing of ball bearings, calculated the | Y| = 0.63mm. Methods as shown in figure 2. The dial indicator is the numerical value of Y.
The influence of tool center of circular interpolation error and method of eliminating (by car sphere as an example)
As shown in Figure 3, the X for tool circular interpolation circle deviate from the Y axis distance, D is the diameter of ball, D1 xoy plane in actual processing diameter: D / 2 for tool radius of circular interpolation. Visible, in the xoy plane, error d=D1-D=2 on X: in xoz plane, a long axis diameter for D1 and short axis diameter D of the oval ball. The error d=D1-D=2 on X with point by point comparison method eliminate the influence of tool circular interpolation circle error.