
B-63944EN-1/02 PROGRAMMING 5.COMPENSATION FUNCTION
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5.4 DETAILS OF CUTTER OR TOOL NOSE RADIUS
COMPENSATION
5.4.1 Overview
The following explanation focuses on tool nose radius compensation,
but applies to cutter compensation as well. Examples in which XY
planes are used, however, apply to cutter compensation only.
- Tool nose radius center offset vector
The tool nose radius center offset vector is a two dimensional vector
equal to the offset value specified in a T code, and the vector is
calculated in the CNC. Its dimension changes block by block
according to tool movement.
This offset vector (simply called vector herein after) is internally
crated by the control unit as required for proper offsetting and to
calculate a tool path with exact offset (by tool nose radius) from the
programmed path.
This vector is deleted by resetting.
The vector always accompanies the tool as the tool advances.
Proper understanding of vector is essential to accurate programming.
Read the description below on how vectors are created carefully.
- G40, G41, G42
G40, G41 or G42 is used to delete or generate vectors.
These codes are used together with G00, G01, G02, or G32 to specify
a mode for tool motion (Offsetting).
G code Workpiece position Function
G40 Neither Tool nose radius compensation cancel
G41 Right Left offset along tool path
G42 Left Right offset along tool path
G41 and G42 specify an offset mode, while G40 specifies cancellation
of the offset.
- Inner side and outer side
When an angle of intersection of the tool paths specified with move
commands for two blocks on the workpiece side is over 180°, it is
referred to as "inner side." When the angle is between 0° and 180°, it
is referred to as "outer side."
Workpiece
α
Programmed path
Inner side
180
°
a0
°
<180
°
Outer side
Workpiece
Programmed path