Re-factor bed calibration point coordinates to match bed CAD data. Tested successfully on MK3 (auto home position not calibrated and calibrated printer and print area position of calibrated printer). MK25 not tested.

Firmware/mesh_bed_calibration.cpp

@@ -57,13 +57,36 @@ const float bed_skew_angle_extreme = (0.25f * M_PI / 180.f);
 
 #ifdef HEATBED_V2
 
-// Positions of the bed reference points in the machine coordinates, referenced to the P.I.N.D.A sensor.
-// The points are the following: center front, center right, center rear, center left.
+/**
+ * [0,0] bed print area point X coordinate in bed coordinates ver. 05d/24V
+ */
+#define BED_PRINT_ZERO_REF_X 2.f
+/**
+ * [0,0] bed print area point Y coordinate in bed coordinates ver. 05d/24V
+ */
+#define BED_PRINT_ZERO_REF_Y 9.4f
+
+/**
+ * @brief Positions of the bed reference points in print area coordinates. ver. 05d/24V
+ *
+ * Numeral constants are in bed coordinates, subtracting macro defined values converts it to print area coordinates.
+ *
+ * The points are the following:
+ * MK2: center front, center right, center rear, center left.
+ * MK25 and MK3: front left, front right, rear right, rear left
+ */
 const float bed_ref_points_4[] PROGMEM = {
-	13.f - BED_ZERO_REF_X,   10.4f - BED_ZERO_REF_Y,
-	221.f - BED_ZERO_REF_X,  10.4f - BED_ZERO_REF_Y,
-	221.f - BED_ZERO_REF_X, 202.4f - BED_ZERO_REF_Y,
-	13.f - BED_ZERO_REF_X, 202.4f - BED_ZERO_REF_Y
+	37.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_X,
+	18.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y,
+
+	245.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER  - SHEET_PRINT_ZERO_REF_X,
+	18.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y,
+
+	245.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER  - SHEET_PRINT_ZERO_REF_X,
+	210.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y,
+
+	37.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER  - SHEET_PRINT_ZERO_REF_X,
+	210.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y
 };
 
 const float bed_ref_points[] PROGMEM = {

Firmware/variants/1_75mm_MK3-EINSy10a-E3Dv6full.h

@@ -76,7 +76,15 @@ const bool Z_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic o
 #define NUM_AXIS 4 // The axis order in all axis related arrays is X, Y, Z, E
 #define HOMING_FEEDRATE {3000, 3000, 800, 0}  // set the homing speeds (mm/min) // 3000 is also valid for stallGuard homing. Valid range: 2200 - 3000
 
-#define DEFAULT_Y_OFFSET    2.f // Offset of [0;0] point, when the printer is not calibrated
+//#define DEFAULT_Y_OFFSET    4.f // Default distance of Y_MIN_POS point from endstop, when the printer is not calibrated.
+/**
+ * [0,0] steel sheet print area point X coordinate in bed print area coordinates
+ */
+#define SHEET_PRINT_ZERO_REF_X 0.f
+/**
+ * [0,0] steel sheet print area point Y coordinate in bed print area coordinates
+ */
+#define SHEET_PRINT_ZERO_REF_Y -2.f
 
 #define DEFAULT_MAX_FEEDRATE          {200, 200, 12, 120}      // (mm/sec)   max feedrate (M203)
 #define DEFAULT_MAX_ACCELERATION      {1000, 1000, 200, 5000}  // (mm/sec^2) max acceleration (M201)
@@ -408,7 +416,7 @@ const bool Z_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic o
 #define MESH_HOME_Z_SEARCH 5 //Z lift for homing, mesh bed leveling etc.
 
 #define X_PROBE_OFFSET_FROM_EXTRUDER 23     // Z probe to nozzle X offset: -left  +right
-#define Y_PROBE_OFFSET_FROM_EXTRUDER 3     // Z probe to nozzle Y offset: -front +behind
+#define Y_PROBE_OFFSET_FROM_EXTRUDER 5     // Z probe to nozzle Y offset: -front +behind
 #define Z_PROBE_OFFSET_FROM_EXTRUDER -0.4  // Z probe to nozzle Z offset: -below (always!)
 #endif