My CR-10S is running Marlin 1.1.7, which has a feature called babystepping. When a print starts, I can double click the console knob on my CR-10S, and then adjust nozzle height real-time.
My understanding of babystepping is that when I use it and get a perfect first layer height, I should update the global Z offset in Simplify3D on the GCode tab, by adding the babystep value to it. That's assuming my Z offset (M851) is set correctly. After that, the next time I print with that profile on that printer, assuming the probe hasn't moved relative to the nozzle, and that I haven't changed the Z offset, little or no babystepping should be required to get the same perfect layer height.
Do I understand this correctly? Because that's not what's happening most of the time. I have to babystep various amounts, in varying directions, each print. Updating the global Z offset in Simplify3D doesn't do what I expect. I can still usually get a good print, but I don't understand.
Why might this be?