Default filament 1.75mm

Marlin/Configuration.h

 #define EXTRUDERS 1
 
 // Generally expected filament diameter (1.75, 2.85, 3.0, ...). Used for Volumetric, Filament Width Sensor, etc.
-#define DEFAULT_NOMINAL_FILAMENT_DIA 3.0
+#define DEFAULT_NOMINAL_FILAMENT_DIA 1.75
 
 // For Cyclops or any "multi-extruder" that shares a single nozzle.
 //#define SINGLENOZZLE

Marlin/Configuration_adv.h

 
         // Turn off the laser on G28 homing.
         //#define LASER_MOVE_G28_OFF
-
       #endif
 
       /**