Adjustable delta_diagonal_rod_trim (#18423)

Marlin/src/gcode/calibrate/M665.cpp

    *    R = delta radius
    *    S = segments per second
    *    X = Alpha (Tower 1) angle trim
-   *    Y = Beta (Tower 2) angle trim
+   *    Y = Beta  (Tower 2) angle trim
    *    Z = Gamma (Tower 3) angle trim
+   *    A = Alpha (Tower 1) digonal rod trim
+   *    B = Beta  (Tower 2) digonal rod trim
+   *    C = Gamma (Tower 3) digonal rod trim
    */
   void GcodeSuite::M665() {
     if (parser.seen('H')) delta_height              = parser.value_linear_units();
     if (parser.seen('X')) delta_tower_angle_trim.a  = parser.value_float();
     if (parser.seen('Y')) delta_tower_angle_trim.b  = parser.value_float();
     if (parser.seen('Z')) delta_tower_angle_trim.c  = parser.value_float();
+    if (parser.seen('A')) delta_diagonal_rod_trim.a = parser.value_float();
+    if (parser.seen('B')) delta_diagonal_rod_trim.b = parser.value_float();
+    if (parser.seen('C')) delta_diagonal_rod_trim.c = parser.value_float();
     recalc_delta_settings();
   }
 

Marlin/src/module/configuration_store.cpp

   //
   #if ENABLED(DELTA)
     float delta_height;                                 // M666 H
-    abc_float_t delta_endstop_adj;                      // M666 XYZ
+    abc_float_t delta_endstop_adj;                      // M666 X Y Z
     float delta_radius,                                 // M665 R
           delta_diagonal_rod,                           // M665 L
           delta_segments_per_second;                    // M665 S
-    abc_float_t delta_tower_angle_trim;                 // M665 XYZ
+    abc_float_t delta_tower_angle_trim,                 // M665 X Y Z
+                delta_diagonal_rod_trim;                // M665 A B C
   #elif HAS_EXTRA_ENDSTOPS
     float x2_endstop_adj,                               // M666 X
           y2_endstop_adj,                               // M666 Y
         EEPROM_WRITE(delta_diagonal_rod);        // 1 float
         EEPROM_WRITE(delta_segments_per_second); // 1 float
         EEPROM_WRITE(delta_tower_angle_trim);    // 3 floats
+        EEPROM_WRITE(delta_diagonal_rod_trim);   // 3 floats
 
       #elif HAS_EXTRA_ENDSTOPS
 
           EEPROM_READ(delta_diagonal_rod);        // 1 float
           EEPROM_READ(delta_segments_per_second); // 1 float
           EEPROM_READ(delta_tower_angle_trim);    // 3 floats
+          EEPROM_READ(delta_diagonal_rod_trim);   // 3 floats
 
         #elif HAS_EXTRA_ENDSTOPS
 
   //
 
   #if ENABLED(DELTA)
-    const abc_float_t adj = DELTA_ENDSTOP_ADJ, dta = DELTA_TOWER_ANGLE_TRIM;
+    const abc_float_t adj = DELTA_ENDSTOP_ADJ, dta = DELTA_TOWER_ANGLE_TRIM, ddr = DELTA_DIAGONAL_ROD_TRIM_TOWER;
     delta_height = DELTA_HEIGHT;
     delta_endstop_adj = adj;
     delta_radius = DELTA_RADIUS;
     delta_diagonal_rod = DELTA_DIAGONAL_ROD;
     delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND;
     delta_tower_angle_trim = dta;
+    delta_diagonal_rod_trim = ddr;
   #endif
 
   #if ENABLED(X_DUAL_ENDSTOPS)
         , SP_Z_STR, LINEAR_UNIT(delta_endstop_adj.c)
       );
 
-      CONFIG_ECHO_HEADING("Delta settings: L<diagonal_rod> R<radius> H<height> S<segments_per_s> XYZ<tower angle corrections>");
+      CONFIG_ECHO_HEADING("Delta settings: L<diagonal rod> R<radius> H<height> S<segments per sec> XYZ<tower angle trim> ABC<rod trim>");
       CONFIG_ECHO_START();
       SERIAL_ECHOLNPAIR_P(
           PSTR("  M665 L"), LINEAR_UNIT(delta_diagonal_rod)
         , SP_X_STR, LINEAR_UNIT(delta_tower_angle_trim.a)
         , SP_Y_STR, LINEAR_UNIT(delta_tower_angle_trim.b)
         , SP_Z_STR, LINEAR_UNIT(delta_tower_angle_trim.c)
+        , PSTR(" A"), LINEAR_UNIT(delta_diagonal_rod_trim.a)
+        , PSTR(" B"), LINEAR_UNIT(delta_diagonal_rod_trim.b)
+        , PSTR(" C"), LINEAR_UNIT(delta_diagonal_rod_trim.c)
       );
 
     #elif HAS_EXTRA_ENDSTOPS

Marlin/src/module/delta.cpp

 xy_float_t delta_tower[ABC];
 abc_float_t delta_diagonal_rod_2_tower;
 float delta_clip_start_height = Z_MAX_POS;
+abc_float_t delta_diagonal_rod_trim;
 
 float delta_safe_distance_from_top();
 
  * settings have been changed (e.g., by M665).
  */
 void recalc_delta_settings() {
-  constexpr abc_float_t trt = DELTA_RADIUS_TRIM_TOWER,
-                        drt = DELTA_DIAGONAL_ROD_TRIM_TOWER;
+  constexpr abc_float_t trt = DELTA_RADIUS_TRIM_TOWER;
   delta_tower[A_AXIS].set(cos(RADIANS(210 + delta_tower_angle_trim.a)) * (delta_radius + trt.a), // front left tower
                           sin(RADIANS(210 + delta_tower_angle_trim.a)) * (delta_radius + trt.a));
   delta_tower[B_AXIS].set(cos(RADIANS(330 + delta_tower_angle_trim.b)) * (delta_radius + trt.b), // front right tower
                           sin(RADIANS(330 + delta_tower_angle_trim.b)) * (delta_radius + trt.b));
   delta_tower[C_AXIS].set(cos(RADIANS( 90 + delta_tower_angle_trim.c)) * (delta_radius + trt.c), // back middle tower
                           sin(RADIANS( 90 + delta_tower_angle_trim.c)) * (delta_radius + trt.c));
-  delta_diagonal_rod_2_tower.set(sq(delta_diagonal_rod + drt.a),
-                                 sq(delta_diagonal_rod + drt.b),
-                                 sq(delta_diagonal_rod + drt.c));
+  delta_diagonal_rod_2_tower.set(sq(delta_diagonal_rod + delta_diagonal_rod_trim.a),
+                                 sq(delta_diagonal_rod + delta_diagonal_rod_trim.b),
+                                 sq(delta_diagonal_rod + delta_diagonal_rod_trim.c));
   update_software_endstops(Z_AXIS);
   set_all_unhomed();
 }

Marlin/src/module/delta.h

 extern xy_float_t delta_tower[ABC];
 extern abc_float_t delta_diagonal_rod_2_tower;
 extern float delta_clip_start_height;
+extern abc_float_t delta_diagonal_rod_trim;
 
 /**
  * Recalculate factors used for delta kinematics whenever