4+4车铣复合仿真G07.1为什么会过切？

POOM*

链接：https://pan.baidu.com/s/1jsc-FnnvJOfZTczRK1ssOw?pwd=7n9g
提取码：7n9g
程序如下
G54 M68
N01 G28 X0 Z0
N02 T1111
M43
G28 C0.
G98 G00 Z20.
G00 X90. Y0  
N03 G97 S1000 M13
N04 G00 X50 Z0
N05 G98 G01 X40 F100
N06 G19 C0 Z0
N07 G07.1 C20
N08 G41
N09 G01 Z-10.C80 F150
N10 Z-25 C90
N11 Z-80 C225
N12 G03 Z-80 C270 R55
N13 G01 Z-25
N14 G02 Z-20 C280 R80
N15 G01 C360
N16 G40
N17 G07.1 C0
N18 G01 X50
N19 G0 X100 Z100
N20 M15
M69
N21 M30