Differences

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--- nozzle_high_above_bed [2026/09/27 22:35] – dshoop
+++ nozzle_high_above_bed [2026/09/27 23:03] (current) – dshoop
@@ Line 4: / Line 4: @@
 HOME doesn't take us to the center of the plate, by homing we send the probe to the trigger position.
-HOME is not where the nozzle is at the center of the bed, it's where the probe is at the center x,y  position, not the nozzle. HOME is also not Z0, unless you’ve changed this, and it should be about 10mm above the bed, yet we expect it to be ~10mm +/- the gcode z offset and a variety of other factors. See [[Layer Height Composition]] for a diagram that explains some to the factors that go into the exact nozzle position.
+HOME is not where the nozzle is at the center of the bed, it's where the probe is at the center x,y  position, not the nozzle. HOME is also not Z0, unless you’ve changed this, and it should be about 10mm above the bed, yet we expect it to be ~10mm +/- the gcode z offset and a variety of other factors. See [[layer_height_compostion|Layer Height Composition]] for a diagram that explains some to the factors that go into the exact nozzle position.
@@ Line 47: / Line 47: @@
 </code>
-This tells us the toolhead (nozzle) thinks its at the ''X:141.000000 Y:98.000000 Z:10.000000'', which is where the probe is at the center of the bed for the Neptune 4 and 4 Pro.
+This tells us the toolhead (nozzle) considers itself at the ''X:141.000000 Y:98.000000 Z:10.000000'' position, which is where the probe is at the center of the bed for the Neptune 4 and 4 Pro.
-However our gcode offsets for x,y,**z** are ''X:0.000000 Y:0.000000 Z:10.010000'' so we're very likely far from the plate.
+However our gcode offsets for x,y,**z** are ''X:0.000000 Y:0.000000 Z:20.010000'' so we're very likely far from the plate, likely about 30mm above the plate.
-Observe above:
+Observe above that ''stepper: stepper_z:1.449000'' is //my// probe z offset value as we're at the probe trigger point position.
+Is your's zero? If so your probe is uncalibrated as this should be the measured z distance between the nozzle and the probe. You're including an adjustment for the lack of this in your gcode z offset and that adjustment value varies.
+In the end what really counts when it all comes down to the actual position that's what's actually being considered by the mcu which uses the mcirostep position of the abstracted stepper motor (micro steps position.)
+Compare this with the following:
+<code>
+G28
+G1 Z10
+GET_POSITION
+</code>
+which should produce something like
+<code>
+// mcu: stepper_x:-334499 stepper_y:312528 stepper_z:-57916
+// stepper: stepper_x:141.000000 stepper_y:98.000000 stepper_z:30.030250
+// kinematic: X:141.000000 Y:98.000000 Z:30.030250
+// toolhead: X:141.000000 Y:98.000000 Z:30.030000 E:40218.477580
+// gcode: X:141.000000 Y:98.000000 Z:30.010000 E:40218.477580
+// gcode base: X:0.000000 Y:0.000000 Z:20.010000 E:40219.677580
+// gcode homing: X:0.000000 Y:0.000000 Z:20.010000
+</code>
+Here the Z10 + the gcode offset has the toolhead (nozzle) at 30.010000mm from the bed.
+Cautiously, compare this with the following:
+<code>
+SET_GCODE_OFFSET Z=0 MOVE=1
+G28
+G1 Z10
+GET_POSITION
+</code>
+which should produce something like
+<code>
+// mcu: stepper_x:-334501 stepper_y:312520 stepper_z:-80780
+// stepper: stepper_x:141.000000 stepper_y:98.000000 stepper_z:1.449000
+// kinematic: X:141.000000 Y:98.000000 Z:1.449000
+// toolhead: X:141.000000 Y:98.000000 Z:10.008409 E:40218.477580
+// gcode: X:141.000000 Y:98.000000 Z:10.000000 E:40218.477580
+// gcode base: X:0.000000 Y:0.000000 Z:0.000000 E:40219.677580
+// gcode homing: X:0.000000 Y:0.000000 Z:0.000000
+</code>
+and the nozzle at about 10mm above the plate.
-''stepper: stepper_z:1.449000'' is my probe z offset value as we're at the probe trigger point and this is