diff --git a/Marlin/src/feature/bedlevel/ubl/ubl.cpp b/Marlin/src/feature/bedlevel/ubl/ubl.cpp index 2dc3013ba0..349377c0c5 100644 --- a/Marlin/src/feature/bedlevel/ubl/ubl.cpp +++ b/Marlin/src/feature/bedlevel/ubl/ubl.cpp @@ -198,8 +198,11 @@ serialprintPGM(csv ? PSTR("CSV:\n") : PSTR("LCD:\n")); } - const float current_xi = get_cell_index_x(current_position[X_AXIS] + (MESH_X_DIST) / 2.0), - current_yi = get_cell_index_y(current_position[Y_AXIS] + (MESH_Y_DIST) / 2.0); + // Add XY_PROBE_OFFSET_FROM_EXTRUDER because probe_pt() subtracts these when + // moving to the xy position to be measured. This ensures better agreement between + // the current Z position after G28 and the mesh values. + const float current_xi = find_closest_x_index(current_position[X_AXIS] + X_PROBE_OFFSET_FROM_EXTRUDER), + current_yi = find_closest_y_index(current_position[Y_AXIS] + Y_PROBE_OFFSET_FROM_EXTRUDER); if (!lcd) SERIAL_EOL(); for (int8_t j = GRID_MAX_POINTS_Y - 1; j >= 0; j--) { diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h index b91104b77a..7f389c3c57 100644 --- a/Marlin/src/inc/Conditionals_post.h +++ b/Marlin/src/inc/Conditionals_post.h @@ -203,11 +203,17 @@ * Safe Homing Options */ #if ENABLED(Z_SAFE_HOMING) + #if ENABLED(AUTO_BED_LEVELING_UBL) + // Home close to center so grid points have z heights very close to 0 + #define _SAFE_POINT(A) (((GRID_MAX_POINTS_##A) / 2) * (A##_BED_SIZE - 2 * (MESH_INSET)) / (GRID_MAX_POINTS_##A - 1) + MESH_INSET) + #else + #define _SAFE_POINT(A) A##_CENTER + #endif #ifndef Z_SAFE_HOMING_X_POINT - #define Z_SAFE_HOMING_X_POINT X_CENTER + #define Z_SAFE_HOMING_X_POINT _SAFE_POINT(X) #endif #ifndef Z_SAFE_HOMING_Y_POINT - #define Z_SAFE_HOMING_Y_POINT Y_CENTER + #define Z_SAFE_HOMING_Y_POINT _SAFE_POINT(Y) #endif #define X_TILT_FULCRUM Z_SAFE_HOMING_X_POINT #define Y_TILT_FULCRUM Z_SAFE_HOMING_Y_POINT