Hi,
you need to look up G31....the probing command.
Amognst the parameters that you program a G31 command is the feed rate (approach speed), it has the usual feed rate symbol F.
But feed rate is modal. So if a series of machining moves is executed at a cutting speed F300, that 300mm/min AND then
a G31 code is called but you omit to specify the reed rate you want to apply Mach will carry on with F300 as had been
already established.
Each and everytime you call a G31 you should include ALL the required parameters including F or you will get some strange
results.
Craig