Filament runout not detected

I am in my 25hour of a 27hour print and ran out of filament. I was sitting there watching the printer to see how the out of filament feature would work.

Well it ran all the filament out, but never reported it. I waited and may have waited too long as I think I got one layer that didn’t completely print, but fed in the new roll of filament as the printer was continuing to print air. It is continuing the print now, hopefully it didn’t ruin anything. this is just a tool holder/organizer so I don’t care if there is a bit of print mess cosmetically.

Any ideas why it didn’t detect this? I would have cared had it been a building or terrain piece.

Yet another “feature” that I thought I bought with this printer that doesn’t appear to work.


How was the print being made?

Were you printing via a USB stick, via WiFi, or via USB cable?

Yea, if it was from Luban the runout detection doesn’t work, only from touchscreen.

In the future, it is possible to recover a print - just gotta find the last gcode that got laid down, which can be done by measuring the height to get the layer, and then playing back in Cura or S3D to estimate where it stopped on what line number. Then just restarting from there after some tweaks to the gcode.

I did that after a 12 hour print that I had no intention on wasting 500g of filament.

Everything was done in Luban and sent to the printer via wifi.

So this doesn’t work?

I finished the print and do see that about 75% of one layer was missed.

If you sent it via wifi and ran it from the touchscreen it should work.

There’s a gcode command that will tell you if the runout sensor is being triggered: M119

When you get a chance to test, run that command from USB (won’t work over wifi, no response) with and without filament. One should say “open” and one should say “TRIGGERED”.

If it’s not getting triggered properly you’re going to have to make sure you hear a click when the filament inserts, and open up the side panel to adjust the microswitch. Something like this: Filament reload... Wait, it's not out of filament

Ok I did send via wifi and run from the touchscreen.

I’ll test later when I have to energy to move my printer back next to my computer :slight_smile:

Maybe I can buy a 50ft usb cable . . .

UGH that’s the worst. Plan on being able to get USB to it occasionally, for setting esteps or other routine testing and maintenance it’s really a necessity.

Did you know there is USB over cat5 for long distances? Standard USB cables only work up to some distance (3m I think).

Another option is getting a raspberry PI (about $30) and setting up Octoprint. That’s popular, can send commands via USB from a web interface, and has many other benefits. Running prints via octoprint though still won’t have filament runout protection, although several people are working on adding that, slowly. It’s not super simple.

I’ve looked briefly at octoprint. I was hoping to be able to buy a kit for it with screen and everything, but haven’t found one yet.

I’ll pick up an extender, easier than moving the printer

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OK when I run M119 I get the same thing with and without filament loaded

Recv: Reporting endstop status
Recv: x_min: open
Recv: x_max: open
Recv: y_min: open
Recv: y_max: open
Recv: z_min: open
Recv: z_max: open
Recv: z_probe: open
Recv: filament: TRIGGERED
Recv: ok


Are you busting my balls? I never knew that.

Why do they sell them so long then lol.

I guess looking at the longer ones they have a little box on one end, must be some kind of active amplifier or something.

Looked it up - 5 meters actually. Lol. And yea, that’s unamplified. Same with Ethernet. You can run past the max 100m distance if you’re willing to sacrifice speed. I’ve installed a camera via PoE 1600ft away over Ethernet using a special injector pair.

I guess i did kind of know that, from the past when fiddling with i/o controllers, but slipped my mind.

i was fixin’ to run a usb to my computer (another room) but maybe ill do the cat 5 to usb thing to give it a whirl.

I bought the one linked above and it works fine. Tested it out.

But in the meantime I also bought a rpi 4, touch screen and put octoprint on it. I used octoprint to test things out.

OK got it working.

The video says to adjust the alignement of the switch. This didn’t fix the issue. Instead it came down to how the tightness of the lower screw that holds the switch in place. If it is too tight the switch will not trigger, too loose and the switch moves.

M119 now returns open and triggered appropriately.


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Interesting, glad to hear you were able to fix it.

That’s a new one that I haven’t seen before, mounting screws so tight it bonds the internals of the mechanism. Thanks for the update.