Back Line
The back line function may be used on any line command. This function reverses the direction of
the programmed line. Back line is normally used when you know the end point of the line and not
its starting point. The end point is programmed and the line is extended backward to the start
point. When using this function all Trig Help functions are still valid.
Example 1:
X6 Y2 X5
X4 Y1.5
G2 R1 XC3 YC1.5 AB270 G1 X1 Y2 BACK C0 W145 X0
Back - extend back from (1,2)
C0 - use the arc intersection closest to (1,2)
W145 - extend the line from (1,2) at an angle of 145°
Example 2:
X6 Y2
X5
X4 Y1.5
G2 R1XC3YC1.5 AB270
G1 X1 Y2 BACK C2 W145
X0
C2 - use the farthest intersection
Example 3:
X6 Y2
X5
X4 Y1.5
X1 Y2 BACK C0 W-35
X0
Note: This example uses a back line between two lines to program an unknown point.