NCT Group 99M Rules of Programming Special Transformations, Rotation-scaling Scaling-rotation

15 Special Transformations

Example:

subprogram

O0101

N1 G90 G0 X180 Y120 F120

N2 G1 X240

N3 Y160

N4 G3 X180 Y120 R80

N5 M99

main program

Fig. 15.3-1

O0100
N1	G90			(absolute coordinate specification)
N2	M98	P101		(call of subprogram)
N3	G51.1		X140	(mirror image applied to an axis parallel to axis Y on
				coordinate X=140)
N4	M98	P101		(call of subprogram)
N5	G51.1		Y100	(mirror image applied to an axis parallel to axis X on
				coordinate Y=100)
N6	M98	P101		(call of subprogram)
N7	G50.1		X0	(canceling mirror image on the axis parallel to Y)
N8	M98	P101		(call of subprogram)
N9	G50.1		Y0	(canceling mirror image on the axis parallel to X)

15.4 Rules of Programming Special Transformations

Rotation and scaling instructions, G68 and G51 can be issued in any order.

It should be borne in mind, however, that - when rotation is followed by scaling - the rotation command will have an effect on the coordinates of the center of scaling. If, on the other hand, scaling is followed by rotation, the scaling command will have an effect on the coordinates of the center of rotation.

Furthermore, the on and off commands of the two procedures have to be "nested", they must not overlap each other:

rotation-scaling					scaling-rotation
N1	G90	G17		G0 X0 Y0	N1	G90	G17		G0 X0 Y0
N2	G68	X80		Y40 R60	N2	G51	X130 Y70 P0.5
N3	G51	X130 Y70 P0.5			N3	G68	X80		Y40 R60
N4	X180		Y40		N4	X180		Y40
N5	G1 Y100			F200	N5	G1 Y100			F200
N6	X80				N6	X80
N7	Y40				N7	Y40
N8	X180				N8	X180
N9	G50				N9	G69
N10 G69			G0	X0 Y0	N10 G50			G0	X0 Y0

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