as a title, a small distraction in writing a gcode, it can cost dear with Mach4 Lathe!
as image, I omitted the value in G1 writing F0.
this was interpreted as a G0 for Mach4!
result ... I destroyed the tool !!!

%
T101
G97 S800 M3
G0 X100 Z10
G1 G99 Z0 F0.2
G1 X-1.6 F0.
G0 X100 Z10
M5
M30
;