Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 506)

Tool Tip Radius Compensation (TTRC)
Function
Chapter 21
21-22
If the next programmed move is circular (an arc), position the tool at right
angles to a tangent line drawn from the start-point of that circular move.
Figure 21.18
Tool Path for Entry Move Straight Line-to-Arc
0 £q £ 90
90 £q £ 180
Programmed path
G41
G42
Start-point
Start-point
Programmed path
G42 G41
180 £q £ 270
270 £q £ 360
Start-point
Start-point
Programmed
Path
G42 G41
q
q
q
q
Programmed path
G41
G42
r
r
r r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
G39 (Linear Generated Blocks)
G39 (Linear Generated Blocks)
G39.1 (Circular Generated Block)
0 £q £ 90
Programmed path
G41
G42
Start-point
q
r
r
r
G39.1 (Circular Generated Block)
270 £q £ 360
Start-point
q
Programmed path
G41
G42
r
r
r