%520 (reine echiquier)
N1 E60000=-58746
N2 E62000=-274649
N3 E62001=+120000
N10 G54 G71 G90
N20 G80 G40
N25 G97 S1000
N30 G0 G52 X0 Z0
N40 T1 D1 M6 (pcln pour mise piece en butee)
N50 G0 X0 Z2
N60 M0
N70 G0 G52 X0 Z0
N80 T2 D2 M6 (contournage ebauche SVJBL)
N81 G0 X35 Z20 M4 M8
N82 G96 S200 
N83 G95 F0.1
N90 G63 N120 N300 X30 Z5 P0.8 EZ-55 EU0 EB-137 EC-95 ER0.2 Q1 EF0.03
N100 G0 G52 X0 Z0 G97 S1000
N110 T2 D20 M6 (correcteur de finition)
N120 G42 G0 X-0.5 Z5 M4 M8
N130 G96 S250
N160 G1 X0 Z0 F0.05
N170 G3 X7.48 Z-5.25 R10
N180 G2 X18.66 Z-4 R30
N190 G1 X23.77 Z-8.87
N200 G2 X18.74 Z-14.26 R12
N210 G2 X20 Z-16.12 R2
N220 G3 X22.52 Z-19.41 R2
N230 G1 X12.28 Z-24.69
N240 G2 X13.41 Z-39.75 R17.5
N250 G2 X16.77 Z-40.75 R1.9
N260 G2 X21.38 Z-43.52 R16.5
N270 G3 X22.52 Z-44.87 R1.9
N280 G1 X22.52 Z-46.37
N290 G1 X25 Z-46.37
N300 G1 X25 Z-55 
N315 G0 X40 M9
N320 G0 G52 X0 Z0 G97 S1000
N325 G40 M5
N326 T3 D3 M6
N327 G0 X28 Z-50.5 M8 M3
N328 G96 S100
N329 G1 X23 Z-53 F0.05
N3290 X0
N3291 G0 X28
N3292 G97 S1000
N3293 G0 G52 X0 Z0 M5 M9
N330 M2