Trying to get my head around these wonderful rules but getting confused, here is what I am doing.
Job is just a circle, 200mm perpendicular lead-in, Torch speed is 1600mm/min, 2mm Overburn, cut rule is set for 0mm before start set cut speed 60% and output THC off code, 0mm before end set cut speed 100% and output THC on code.
You said you put your thc off code “on start”
What on start does, is :
on start of cut, go X distance at % speed, then output …code.
if distance is 0, speed wont change, but it will still output the code.
you can just create a rule for circles…smaller than…(for this job, put 250mm) feedrate…(put your60% here)
start code: will output that code at the beginning of the circle
end code: will output that code when the circle is done.
In line N0150 we turn the torch on for the pierce, and then in line N0180 we turn off THC, I guess this will work as the machine is not moving during pierce, Mach3 will ignore any THC inputs plus there is a delay in the THC unit which does not output any signal for a pre-set time.