diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index d3dbc83a3e..15297f7e64 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -767,6 +767,34 @@
#define HOME_AFTER_G34
#endif
+//
+// Add the G35 command to read bed corners to help adjust screws.
+//
+//#define ASSISTED_TRAMMING
+#if ENABLED(ASSISTED_TRAMMING)
+
+ // Define positions for probing points, use the hotend as reference not the sensor.
+ #define TRAMMING_POINT_XY { { 20, 20 }, { 200, 20 }, { 200, 200 }, { 20, 200 } }
+
+ // Define positions names for probing points.
+ #define TRAMMING_POINT_NAME_1 "Front-Left"
+ #define TRAMMING_POINT_NAME_2 "Front-Right"
+ #define TRAMMING_POINT_NAME_3 "Back-Right"
+ #define TRAMMING_POINT_NAME_4 "Back-Left"
+
+ // Enable to restore leveling setup after operation
+ #define RESTORE_LEVELING_AFTER_G35
+
+ /**
+ * Screw thread:
+ * M3: 30 = Clockwise, 31 = Counter-Clockwise
+ * M4: 40 = Clockwise, 41 = Counter-Clockwise
+ * M5: 50 = Clockwise, 51 = Counter-Clockwise
+ */
+ #define TRAMMING_SCREW_THREAD 30
+
+#endif
+
// @section motion
#define AXIS_RELATIVE_MODES { false, false, false, false }
diff --git a/Marlin/src/gcode/bedlevel/G35.cpp b/Marlin/src/gcode/bedlevel/G35.cpp
new file mode 100755
index 0000000000..7a42744c74
--- /dev/null
+++ b/Marlin/src/gcode/bedlevel/G35.cpp
@@ -0,0 +1,192 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(ASSISTED_TRAMMING)
+
+#include "../gcode.h"
+#include "../../module/planner.h"
+#include "../../module/probe.h"
+#include "../../feature/bedlevel/bedlevel.h"
+
+#define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
+#include "../../core/debug_out.h"
+
+constexpr xy_pos_t screws_tilt_adjust_pos[] = TRAMMING_POINT_XY;
+
+static PGMSTR(point_name_1, TRAMMING_POINT_NAME_1);
+static PGMSTR(point_name_2, TRAMMING_POINT_NAME_2);
+static PGMSTR(point_name_3, TRAMMING_POINT_NAME_3);
+#ifdef TRAMMING_POINT_NAME_4
+ static PGMSTR(point_name_4, TRAMMING_POINT_NAME_4);
+ #ifdef TRAMMING_POINT_NAME_5
+ static PGMSTR(point_name_5, TRAMMING_POINT_NAME_5);
+ #endif
+#endif
+
+static PGM_P const tramming_point_name[] PROGMEM = {
+ point_name_1, point_name_2, point_name_3
+ #ifdef TRAMMING_POINT_NAME_4
+ , point_name_4
+ #ifdef TRAMMING_POINT_NAME_5
+ , point_name_5
+ #endif
+ #endif
+};
+
+#define G35_PROBE_COUNT COUNT(screws_tilt_adjust_pos)
+
+#if !WITHIN(TRAMMING_SCREW_THREAD, 30, 51) || TRAMMING_SCREW_THREAD % 10 > 1
+ #error "TRAMMING_SCREW_THREAD must be equal to 30, 31, 40, 41, 50, or 51."
+#endif
+
+static_assert(G35_PROBE_COUNT > 2, "TRAMMING_POINT_XY requires at least 3 XY positions.");
+
+/**
+ * G35: Read bed corners to help adjust bed screws
+ *
+ * S
+ *
+ * Screw thread: 30 - Clockwise M3
+ * 31 - Counter-Clockwise M3
+ * 40 - Clockwise M4
+ * 41 - Counter-Clockwise M4
+ * 50 - Clockwise M5
+ * 51 - Counter-Clockwise M5
+ **/
+void GcodeSuite::G35() {
+ if (DEBUGGING(LEVELING)) {
+ DEBUG_ECHOLNPGM(">>> G35");
+ log_machine_info();
+ }
+
+ float z_measured[G35_PROBE_COUNT] = { 0 };
+
+ const uint8_t screw_thread = parser.byteval('S', TRAMMING_SCREW_THREAD);
+ if (!WITHIN(screw_thread, 30, 51) || screw_thread % 10 > 1) {
+ SERIAL_ECHOLNPGM("?(S)crew thread must be 30, 31, 40, 41, 50, or 51.");
+ goto EXIT_G35;
+ }
+
+ // Wait for planner moves to finish!
+ planner.synchronize();
+
+ // Disable the leveling matrix before auto-aligning
+ #if HAS_LEVELING
+ TERN_(RESTORE_LEVELING_AFTER_G35, const bool leveling_was_active = planner.leveling_active);
+ set_bed_leveling_enabled(false);
+ #endif
+
+ #if ENABLED(CNC_WORKSPACE_PLANES)
+ workspace_plane = PLANE_XY;
+ #endif
+
+ // Always home with tool 0 active
+ #if HAS_MULTI_HOTEND
+ const uint8_t old_tool_index = active_extruder;
+ tool_change(0, true);
+ #endif
+
+ #if HAS_DUPLICATION_MODE
+ extruder_duplication_enabled = false;
+ #endif
+
+ // Home all before this procedure
+ home_all_axes();
+
+ bool err_break = false;
+
+ // Probe all positions
+ LOOP_L_N(i, G35_PROBE_COUNT) {
+
+ // In BLTOUCH HS mode, the probe travels in a deployed state.
+ // Users of G35 might have a badly misaligned bed, so raise Z by the
+ // length of the deployed pin (BLTOUCH stroke < 7mm)
+ current_position.z = (Z_CLEARANCE_BETWEEN_PROBES) + (7 * ENABLED(BLTOUCH_HS_MODE));
+
+ const float z_probed_height = probe.probe_at_point(screws_tilt_adjust_pos[i], PROBE_PT_RAISE, 0, true);
+
+ if (isnan(z_probed_height)) {
+ SERIAL_ECHOLNPAIR("G35 failed at point ", int(i), " (", tramming_point_name[i], ")"
+ " X", screws_tilt_adjust_pos[i].x,
+ " Y", screws_tilt_adjust_pos[i].y);
+ err_break = true;
+ break;
+ }
+
+ if (DEBUGGING(LEVELING))
+ DEBUG_ECHOLNPAIR("Probing point ", int(i), " (", tramming_point_name[i], ")"
+ " X", screws_tilt_adjust_pos[i].x,
+ " Y", screws_tilt_adjust_pos[i].y,
+ " Z", z_probed_height);
+
+ z_measured[i] = z_probed_height;
+ }
+
+ if (!err_break) {
+ const float threads_factor[] = { 0.5, 0.7, 0.8 };
+
+ // Calculate adjusts
+ LOOP_S_L_N(i, 1, G35_PROBE_COUNT) {
+ const float diff = z_measured[0] - z_measured[i],
+ adjust = abs(diff) < 0.001f ? 0 : diff / threads_factor[(screw_thread - 30) / 10];
+
+ const int full_turns = trunc(adjust);
+ const float decimal_part = adjust - float(full_turns);
+ const int minutes = trunc(decimal_part * 60.0f);
+
+ SERIAL_ECHOPAIR("Turn ", tramming_point_name[i],
+ " ", (screw_thread & 1) == (adjust > 0) ? "Counter-Clockwise" : "Clockwise",
+ "by ", abs(full_turns), " turns");
+ if (minutes) SERIAL_ECHOPAIR(" and ", abs(minutes), " minutes");
+ SERIAL_EOL();
+ }
+ }
+ else
+ SERIAL_ECHOLNPGM("G35 aborted.");
+
+ // Restore the active tool after homing
+ #if HAS_MULTI_HOTEND
+ tool_change(old_tool_index, DISABLED(PARKING_EXTRUDER)); // Fetch previous toolhead if not PARKING_EXTRUDER
+ #endif
+
+ #if BOTH(HAS_LEVELING, RESTORE_LEVELING_AFTER_G35)
+ set_bed_leveling_enabled(leveling_was_active);
+ #endif
+
+ // Stow the probe, as the last call to probe.probe_at_point(...) left
+ // the probe deployed if it was successful.
+ probe.stow();
+
+ // After this operation the Z position needs correction
+ set_axis_not_trusted(Z_AXIS);
+
+ // Home Z after the alignment procedure
+ process_subcommands_now_P(PSTR("G28Z"));
+
+ EXIT_G35:
+
+ if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("<<< G35");
+}
+
+#endif // ASSISTED_TRAMMING
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 859826ca2e..960acc3040 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -321,6 +321,10 @@ void GcodeSuite::process_parsed_command(const bool no_ok/*=false*/) {
case 34: G34(); break; // G34: Z Stepper automatic alignment using probe
#endif
+ #if ENABLED(ASSISTED_TRAMMING)
+ case 35: G35(); break; // G35: Read four bed corners to help adjust bed screws
+ #endif
+
#if ENABLED(G38_PROBE_TARGET)
case 38: // G38.2, G38.3: Probe towards target
if (WITHIN(parser.subcode, 2,
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index 06fcce0fa3..8548f3a60c 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -65,6 +65,7 @@
* G32 - Undock sled (Z_PROBE_SLED only)
* G33 - Delta Auto-Calibration (Requires DELTA_AUTO_CALIBRATION)
* G34 - Z Stepper automatic alignment using probe: I T A (Requires Z_STEPPER_AUTO_ALIGN)
+ * G35 - Read bed corners to help adjust bed screws: T (Requires ASSISTED_TRAMMING)
* G38 - Probe in any direction using the Z_MIN_PROBE (Requires G38_PROBE_TARGET)
* G42 - Coordinated move to a mesh point (Requires MESH_BED_LEVELING, AUTO_BED_LEVELING_BLINEAR, or AUTO_BED_LEVELING_UBL)
* G60 - Save current position. (Requires SAVED_POSITIONS)
@@ -454,6 +455,8 @@ private:
static void M422();
#endif
+ TERN_(ASSISTED_TRAMMING, static void G35());
+
TERN_(G38_PROBE_TARGET, static void G38(const int8_t subcode));
TERN_(HAS_MESH, static void G42());
diff --git a/buildroot/share/tests/DUE-tests b/buildroot/share/tests/DUE-tests
index 0243944cf1..5c36db0367 100755
--- a/buildroot/share/tests/DUE-tests
+++ b/buildroot/share/tests/DUE-tests
@@ -14,7 +14,7 @@ opt_set TEMP_SENSOR_BED 2
opt_set GRID_MAX_POINTS_X 16
opt_set FANMUX0_PIN 53
opt_enable S_CURVE_ACCELERATION EEPROM_SETTINGS GCODE_MACROS \
- PIDTEMPBED FIX_MOUNTED_PROBE Z_SAFE_HOMING CODEPENDENT_XY_HOMING \
+ FIX_MOUNTED_PROBE Z_SAFE_HOMING CODEPENDENT_XY_HOMING ASSISTED_TRAMMING \
EEPROM_SETTINGS SDSUPPORT BINARY_FILE_TRANSFER \
BLINKM PCA9533 PCA9632 RGB_LED RGB_LED_R_PIN RGB_LED_G_PIN RGB_LED_B_PIN LED_CONTROL_MENU \
NEOPIXEL_LED CASE_LIGHT_ENABLE CASE_LIGHT_USE_NEOPIXEL CASE_LIGHT_MENU \
@@ -24,7 +24,7 @@ opt_enable S_CURVE_ACCELERATION EEPROM_SETTINGS GCODE_MACROS \
BACKLASH_COMPENSATION BACKLASH_GCODE BAUD_RATE_GCODE BEZIER_CURVE_SUPPORT \
FWRETRACT ARC_SUPPORT ARC_P_CIRCLES CNC_WORKSPACE_PLANES CNC_COORDINATE_SYSTEMS \
PSU_CONTROL AUTO_POWER_CONTROL \
- SLOW_PWM_HEATERS THERMAL_PROTECTION_CHAMBER \
+ PIDTEMPBED SLOW_PWM_HEATERS THERMAL_PROTECTION_CHAMBER \
PINS_DEBUGGING MAX7219_DEBUG M114_DETAIL \
EXTENSIBLE_UI
opt_add EXTUI_EXAMPLE