Compensation Of Leadscrew Errors And Measuring System Errors; Description Of Functions - Siemens SINUMERIK 840D sl Function Manual

K3: Compensation
5.4 Interpolatory compensation
Linear interpolation between interpolation points
The traversing path to be compensated delineated by the start and end positions is divided
up into several (number depends on error curve shape) path segments of equal size (see
diagram below). The actual positions that limit these sub-paths are referred to as
"interpolation points" below. A compensation value must be entered for each interpolation
point (actual position) during commissioning. The compensation value applied between 2
interpolation points is generated on the basis of linear interpolation using the compensation
values for the adjacent interpolation points (i.e. adjacent interpolation points are linked along
a line).
Figure 5-4
Compensation value at reference point
The compensation table should be structured such that the compensation value at the
reference point is "zero".
5.4.2

Compensation of leadscrew errors and measuring system errors

5.4.2.1

Description of functions

Leadscrew and measuring system errors
The measuring principle of "indirect measurement" on NC-controlled machines is based on
the assumption that the lead of the ball screw is constant at any point within the traversing
range, so that the actual position of the axis can be derived from the position of the drive
spindle (ideal case). However, manufacturing tolerances result in dimensional deviations of
varying degrees of severity on spindles (so-called leadscrew errors).
Added to this are the dimensional deviations (differences in reference division) caused by
the measuring system as well as its mounting on the machine (so-called measuring system
errors), plus any machine-dependent error sources.
358
Linear interpolation between the interpolation points
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions