Selecting The Trc (G41/G42) - Siemens SINUMERIK 840D sl Function Manual

Why TRC?
The contour (geometry) of the workpiece programmed in the part program should be
independent of the tools used in production. This makes it necessary to obtain the values for
the tool length and tool radius from a current offset memory. With the current tool radius, tool
radius compensation (TRC) can be used to calculate the equidistant path to the programmed
contour in the plane.
Figure 2-2
TRC on the plane
TRC is active on the current plane (G17 to G19) for the following types of interpolation:
● Linear interpolation
● Circular interpolation
● Helical interpolation
● Spline interpolation
● Polynomial interpolation
2.5.2

Selecting the TRC (G41/G42)

Direction of compensation
TRC calculates a path, which is equidistant to the programmed contour. Compensation can be
performed on the left- or righthand side of the programmed contour in the direction of motion.
Command
G41
G42
G40
Tools
Function Manual, 06/2019, A5E47435126B AA
Workpiece contour (geometry) with equidistant path
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Significance
TRC on the lefthand side of the contour in the direction of motion
TRC on the righthand side of the contour in the direction of motion
Deselection of TRC
G0, G1
G2, G3, CIP
G2, G3
ASPLINE, BSPLINE, CSPLINE
POLY
W1: Tool offset
2.5 2D tool radius compensation
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