Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 494)

Tool Tip Radius Compensation (TTRC)
Function
Chapter 21
21-10
The easiest way to demonstrate the cutting tool’s the actual tool paths when
using TTRC type A is by pictorial representation. The following
subsections describe the cutter path along with a figure to clarify the
description
An entry move is defined as the path that the cutting tool takes when the
TTRC function first becomes activated in a program. Figure 21.7 shows a
typical entry move.
Figure 21.7
TTRC Entry Move
Compensation entry move
Workpiece
Programmed tool path
Cutting tool center path
G42 TTRC right
Cutting tool
Important: Any entry move into TTRC must be a linear move. Initial
activation of TTRC by designation of either the G41, G42, or T-word that
initializes TTRC in a circular cutting mode (G02 or G03) is not allowed.
The G41, G42, or T-word can be designated in a circular block to change
TTRC direction or tool radius, as long as TTRC is already active.
The entry move of the cutting tool for type A TTRC takes the shortest
possible path to its offset position. This position is at right angles to and
on the left or right side of the next programmed move in the currently
defined plane.
Figure 21.8 and Figure 21.9 show examples of typical entry moves using
type A TTRC.
21.3
TTRC Tool Paths (Type A)
21.3.1
TTRC Type A Entry Moves