Zero filament detector

Sovol Zero
1

By mistake, I started a print job without any filament loaded.

It pretended to print nonetheless, does it mean my Zero filament detector (or, worse, the motherboard) is faulty, or is there anything in firmware 1.4.7 that disabled it, like the pressure sensor, to make another example?

2

How long does it take between the start of the false impression and the stop?
There may be a delay of detection.

3

This should be just a filament detector issue.
Check that’s it’s working correctly, plugged in, light is on, no filament stuck inside.

I know the sensor works, I’ve tested it…but I’ve never tried to bypass it.
I’m not sure if it works the same in Klipper as it does in Marlin.

1 Like
4

I will test this, however, I cannot right now because I have another problem that prevents any use right now :sweat_smile: :sob:

5

You may have disabled the filament sensor being active from the UI:
image

2 Likes
6

Also Mainsail, Fluid and Klipperscreen all have one click buttons to disable the filament sensor. Not sure about the Zero knobscreen

7

I tested it, and the out of filament condition was detected, both in Mainsail and in the printer’s little display.

However, the printer didn’t pause nor stop, it kept on printing, as I previously noticed (in reply to @Vergo, the switch was not in the disabled position even then, I made sure it wasn’t and checked it with attention, as it was my first suspicion too).

So, I’ve let it continue printing, to check when it would eventually pause and report (besides the “out of filament” line, I mean, but truly prompting me a filament change), and it indeed paused around 20 cm after the filament sensor, but still enough to permit filament unload from here:

photo_2025-06-05_19-46-23
photo_2025-06-05_19-46-23670Ă—1280 52.9 KB

rather than more downstream, where it would have required bowden tube removal from the head to unload the remaining filament.

So, it works, and it keeps on printing an intelligent amount of filament, as when the out of filament condition is detected, it’s anyway too late to let it get out from the sensor, so it has to continue. Only, the manual states that you have to remove the bowden tube right after the filament sensor, while real test (at least on my 1.4.7 setup) has shown that the “station” is the next one, as shown in the photo. Not a problem, at all, and more clever than the position stated in the user manual, but it’s good to know where you have to unload the filament if it runs out, else (or at least it happened to me) you may even doubt it really works.

1 Like
8

It is customizable in printer.cfg

[filament_switch_sensor filament_sensor]
pause_on_runout: False
switch_pin: PB2
runout_gcode:
    M117 Out of Filament
    CONTINUE_PRINT_D D={200}
1 Like
9

Thank you, that file is always full of interesting stuff to tweak.