<p>Homing does work as expected, it hits the X and Y end stops, then it moves to the center of the bed (corrected for probe position) and homes Z (this is caused by firmware option <code>#define Z_SAFE_HOMING</code>). As the X and Y endstops are hit the printer knows the position and the location. If your printer now prints in the wrong area, the slicing is probably incorrect, the center of the bed (corrected for probe offset) is never the starting point relative to where the print starts.</p>
<p>The whole purpose of the filament detection sensor is to detect a run out of filament, if run out, the printer stops. So if no filament is detected, it is imaginable that also homing fails. Considering that the homing fails if filament is present in the sensor and not when there is no filament could hint that the filament sensor is incorrectly wired. I would skip the sensor and never use it, it is a pretty useless feature, in the past 10 years and kilometers of filament (1.75 mm and 2.85 mm) I have seldomly encountered broken filament, actually only with the thicker filament and usage of old brittle PLA. Just make sure you have enough filament to finish the print. If your spool has few windings, count the windings and calculate how much is left or unwind the spool and measure the length and compare that to the length the print requires (reported by the slicer). You never run out of filament if you know you have enough.</p>

CC BY-SA 4.0
2023-12-23T20:59:16.030Z
The issue with the run-out detection isn’t that it fails when no filament is detected. Homing fails when it does detect filament. So taking out the filament during the homing process at the start of a print, allows it to home, but then the print would just start without any prompt to reload filament or anything.
Asher Lemme
CC BY-SA 4.0
2023-12-23T23:17:32.823Z
Also the printer is still set up with the default firmware. Neither I nor the owner have ever upgraded it. I wasn’t trying to hint at there being an incorrectly configured firmware. All I was saying was that upgrading the firmware was next on my to-do list. It had been highly suggested by both other users and Creality support to try it in order to single out any homing bugs that could have surfaced.
Asher Lemme
CC BY-SA 4.0
2023-12-23T16:19:53.293Z
2023-12-24T09:16:34.230Z
2023-12-24T09:16:34.230Z
0scar
<p>My friend has an Ender 3 Max Neo that they were just able to reassemble after moving. Looking it over there didn’t seem to be any assembly errors, but the auto-home was definitely causing a few issues.</p>
<ol>
<li><p>The Printer would hit the end stops for X and Y, auto-home to X:157 and Y:170 to test the Z (where the CR Touch would tap with about 2 mm between the bed and the extruder), then raise the extruder to 10 mm (technically 12).</p>
</li>
<li><p>The printer would then stay in that position (X:157 Y:170 Z:10) even though the owner has never had that as the home location. Starting a print right here then causes the printer to try to go off the right side.</p>
</li>
<li><p>The printer also can’t seem to auto-home with any filament in the run-out detection. Starting a print, or telling the printer to auto-home, causes the printer to pull the filament out of the extruder and feeder line until it's past the gears. If I don’t pull it out of the run-out detection then it just says “Homing failed” and can’t be exited unless the entire thing is turned off and then turned back on. At first, I thought this was because of a loose length of filament that had been in the feeder line left over from before. But removing that didn’t stop the issue from occurring with a freshly inserted strand from the spool.</p>
</li>
</ol>
<p>My next plan of action is to re-install the firmware and double-check all the wirings.</p>

CC BY-SA 4.0
2023-12-23T16:15:10.563Z
With the last statement (`My next plan of action is to install the software again and double-check all the wirings.`) we can assume that you are hinting that the current firmware is not the default Creality firmware. So, is this a complete new Marlin configuration you are trying to get right?
0scar
CC BY-SA 4.0
2023-12-23T20:56:51.993Z
So right now it is on V 1.2.3_G so I was planning on just upgrading to the newest Marlin configuration on the Creality Website. A few people on Reddit did so and said it worked fine.The owner hasn’t ever updated it or anything, and the Creality support said that there could be a bug with homing that could be fixed with a firmware update.
Asher Lemme
CC BY-SA 4.0
2023-12-24T09:02:54.490Z
Thanks for the clarification, I will adjust the answer!
0scar
<creality-ender-3><homing>
Homing fails with filament in run-out sensor
Asher Lemme
# Homing fails with filament in run-out sensor

(Asked by: username_0 on 2023-12-22)

My friend has an Ender 3 Max Neo that they were just able to reassemble after moving. Looking it over there didn’t seem to be any assembly errors, but the auto-home was definitely causing a few issues.

1. The Printer would hit the end stops for X and Y, auto-home to X:157 and Y:170 to test the Z (where the CR Touch would tap with about 2 mm between the bed and the extruder), then raise the extruder to 10 mm (technically 12).
2. The printer would then stay in that position (X:157 Y:170 Z:10) even though the owner has never had that as the home location. Starting a print right here then causes the printer to try to go off the right side.
3. The printer also can’t seem to auto-home with any filament in the run-out detection. Starting a print, or telling the printer to auto-home, causes the printer to pull the filament out of the extruder and feeder line until it's past the gears. If I don’t pull it out of the run-out detection then it just says “Homing failed” and can’t be exited unless the entire thing is turned off and then turned back on. At first, I thought this was because of a loose length of filament that had been in the feeder line left over from before. But removing that didn’t stop the issue from occurring with a freshly inserted strand from the spool.

My next plan of action is to re-install the firmware and double-check all the wirings.

**Tags:** creality-ender-3, homing

> **Comments:**
> **username_1**: With the last statement (`My next plan of action is to install the software again and double-check all the wirings.`) we can assume that you are hinting that the current firmware is not the default Creality firmware. So, is this a complete new Marlin configuration you are trying to get right?  
> **username_0**: So right now it is on V 1.2.3_G so I was planning on just upgrading to the newest Marlin configuration on the Creality Website. A few people on Reddit did so and said it worked fine.The owner hasn’t ever updated it or anything, and the Creality support said that there could be a bug with homing that could be fixed with a firmware update.  
> **username_1**: Thanks for the clarification, I will adjust the answer!  

---

## 1 answers

### Answer by username_1 on 2023-12-23. Score: 1

Homing does work as expected, it hits the X and Y end stops, then it moves to the center of the bed (corrected for probe position) and homes Z (this is caused by firmware option `#define Z_SAFE_HOMING`). As the X and Y endstops are hit the printer knows the position and the location. If your printer now prints in the wrong area, the slicing is probably incorrect, the center of the bed (corrected for probe offset) is never the starting point relative to where the print starts.

The whole purpose of the filament detection sensor is to detect a run out of filament, if run out, the printer stops. So if no filament is detected, it is imaginable that also homing fails. Considering that the homing fails if filament is present in the sensor and not when there is no filament could hint that the filament sensor is incorrectly wired. I would skip the sensor and never use it, it is a pretty useless feature, in the past 10 years and kilometers of filament (1.75 mm and 2.85 mm) I have seldomly encountered broken filament, actually only with the thicker filament and usage of old brittle PLA. Just make sure you have enough filament to finish the print. If your spool has few windings, count the windings and calculate how much is left or unwind the spool and measure the length and compare that to the length the print requires (reported by the slicer). You never run out of filament if you know you have enough.

> **Comments:**
> **username_0**: The issue with the run-out detection isn’t that it fails when no filament is detected. Homing fails when it does detect filament. So taking out the filament during the homing process at the start of a print, allows it to home, but then the print would just start without any prompt to reload filament or anything.  
> **username_0**: Also the printer is still set up with the default firmware. Neither I nor the owner have ever upgraded it. I wasn’t trying to hint at there being an incorrectly configured firmware. All I was saying was that upgrading the firmware was next on my to-do list. It had been highly suggested by both other users and Creality support to try it in order to single out any homing bugs that could have surfaced.  

---

