Lately  has been skipping a beat for me.

Lately #simplfy3d has been skipping a beat for me. First time the Z steps were off, a 20mm cube came out 24mm tall now the extruder is spinning about 300 mph and shredding the filament. If i do a extruder calibration of 50mm it is correct but then slice and print, not good. If i slice in Cura then print in S3D it is fine for some reason it has been changing the EEPROM, i guess. This is happening on 2 printers not just one. Kinda irritated $140 and all.

Check if s3d has relative or absolute extrusion turned on.

There is relative extrusion distance and it is unchecked. Should it be?

@Wayne_Friedt depends on your machine. If the machine is set to relative and you send absolute code, it will start off fine then quickly go crazy over extrusion. Check your gcode to see what simplify thinks it’s using. You can force the bot to absolute positioning by using the G90 command before starting the print.

Back in the drivers seat again. I reset back to factory specs then reset up all my other settings.