Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 511)

Dresser/Wheel Radius Compensation
Chapter 15
15-23
If the last programmed move is circular (an arc), the dresser/wheel is
positioned at a right angle to a tangent line drawn from the end-point of
that circular move.
Figure 15.18
Dresser/Wheel Path for Exit Move Arc-to-Straight Line
0
≤ θ ≤
90
θ
Programmed path
End-point
G42 G41
r
r
Programmed path
End-point
G42
G41
r
θ
Programmed path
End-point
G42 G41
r
r
θ
G42
G41
r
r
90
≤ θ ≤
180
θ
End-point
180
≤ θ ≤
270
Programmed path
270
≤ θ ≤
360
12110-I
Figure 15.17 and Figure 15.18 assume that the number of non-motion
blocks does not exceed an amount selected in AMP by your system
installer. If the number of non-motion blocks following G40 exceeds the
limit, the control generates its own exit move. This can often cause
overcutting of the part. See page 15-46 for details on too many
non-motion blocks.