The G51 command allows scaling mode to be used with computer numerical control systems.

For each of the axes, it is possible to specify a scaling factor.

An example of using the G51 command (G-code) below:

N001 G0 X1 Y1                ;Rapid position to point (X position is 1, Y position is 1.)
N002 G51 X3.0                ;Activate scaling on X axis (scale factor = 3)
N003 G0 X4.0                  ;Rapid position to point (X position is 12 = 4 * 3.)
N004 G50                        ;Cancel Scaling

To mirror the CNC program (G-code) , a negative scaling factor is entered.

N001 G0 X2 Y2                ;Rapid position to point (X position is 2, Y position is 2.)
N002 G51 X-1.0                ;Activate scaling on X axis (scale factor = -1)
N003 G0 X4.0                  ;Rapid position to point (X position is -4 = 4 * (-1).)
N004 G50                        ;Cancel Scaling

The cancellation of the scaling mode of the computer numerical control system is performed by the G50 command.

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