Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 79)

Offset Table and Setup
Chapter 3
3-5
Tool Diameter Wear Compensation Data (Wear Table)
The tool diameter wear compensation feature takes into account the wear
that a tool diameter will incur from normal usage. Enter a value in the
wear table that is equal to the difference in tool diameter as entered in the
geometry table and the actual tool diameter. The value entered as tool
diameter wear is subtracted from the current value for the tool diameter
taken from the geometry offset table when a D--word is designated in a part
program.
The system installer determines if radius or diameter values are entered in
the offset table. This manual assumes that the system installer requires
diameter values to be entered.
This feature allows the compensation for slight changes in tool diameter
without the need to change the tool geometry table. Then when a worn
tool is replaced with an identical tool the wear offset needs to be reset to
zero. The tool geometry value should never need to be altered once the
initial value is entered as long as identical tools are always used when
replacing tools.
There are six methods for modifying tool offset tables. These are
discussed in the following chapters and sections:
Using {MEASURE} (section 3.1.3)
Programming G10s (chapter 20)
Skip functions using a probe (chapter 27)
Setting Paramacro System Parameters (chapter 28 )
Altering through the PAL program
When PAL is used to modify either the work coordinate system
tables or the tool offset tables, cutter compensation should not be
active (G40 mode). If cutter compensation is active, be aware that
the new offset will not be placed in part program set-up buffers that
have already been read into control memory. This will result in the
offset not being activated until several program blocks after the
current block. The number of setup buffers is dependent on the
number of block retrace steps configured in AMP and what software
features are currently being used.
The sixth method, and the one discussed here, lets you directly key in to
the offset table offset data that is manually measured.
3.1.2
Setting Tool Offset Tables