System information

SECTION FOUR - PREPARATORY FUNCTIONS (G CODES)
Back line
The back line function can be used on any line command. This function reverses the direction of
a programmed line. It would normally be used when you know the end point of the line and not
its start point. The end point would be programmed and the line would be extended backwards to
the start point. All Trig Help functions are still valid when using this function.
X0 Y0
X3 Y1
G2 R1 XC3 YC0 AB270
G01 X0 Y0 BACK C2 W165
Back Extends line backwards from (0,0)
C2 Uses the arc intersection farthest from (0,0)
W165 Extends the line from (0,0) at an angle of 165°
X0 Y0
X3 Y1
G17 G2 R1 XC3 YC0 AB270
G01 X0 Y0 BACK C0 W165
C0 Uses closest intersection
X0 Y0
X3 Y1
G2 R1 XC3 YC0 X3 Y-1
G01 X0 Y0 BACK C0 W135
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