M03S600

G00X60Y60

Z5

G4 1X40D0 1

G0 1Z-3F60

Y-30

G02X30Y-40

G0 1X-30

G02X-40Y-30

G0 1Y30

G02X-30Y40

G0 1X30

G02X40Y30

Z3

G00Z 100

X 100

Y 100

M05

M30

Frank's system was used, and the left knife was added to make up three in the Z direction.