Octoprint and Filamentsensor  

RE: Octoprint and Filamentsensor

Posted by: @4-unique-dogs

I have already searched the forum but have not received a suitable answer to my question.
I will get my MK3S + in the next few days.
I am currently using an Artillery Sidewinder X1. For this I ran Octoprint on a Raspberry 4.
If you print via Octoprint then the filament sensor is ignored. Therefore I branched off from the sensor GND and signal and plugged them into the GPIO of the Raspberry. This works for the Sidewinder.
I want to use the same Raspberry for the Prusa. A second instance of Octoprint is already running.

My questions:
Has anyone already done that with the GND and signal of the sensor to the GPIO of the Raspberry?
How did you branch that off? Which plugs did you use?

Alternatively:
Is it possible to save GCode files on the SD card of the Prusa via Octoprint? (This doesn't work with the Sidewinder)
If you start with Octoprint G codes from the SD card, is the filament sensor fully functional?

Thank you for your answers and help

On the Mk3S, the filament sensor is not ignored, or at least it is not ignored on my printers when using a Raspberry Pi.  I print almost exclusively with a Pi.  It registers a filament runout and triggers a new filament to be loaded.  

The Mini is not quite so lucky.  

RE: Octoprint and Filamentsensor

@cwbullet

Do you print the files from the printer's SD card or do you save the Gcode on the Pi and do the printing from there?
I have read that Octopi ignores the filament sensor when you start prints on the Pi that are stored on the Pi itself.
It only works if you start prints from the Pi that are stored on the printer's SD card.
Can you help me and explain how you do it. Because the sensor works for you.

RE: Octoprint and Filamentsensor

I have switched from using the SD card to using the storage on the RPI exclusively (octoprint behaves better).  No issues at all with the filament sensor.  I also was able to initiate a filament change when printing from the card - so no, Octoprint doesn't ignore the filament sensor on my MK3S.  I am pretty sure though that Octoprint has no role in filament sensor behavior on the MK3s - so maybe it is ignoring it - I don't know - I don't know what I would want octoprint to do when filament runs out - other than wait for the "paused waiting for user" state to stop and then resume the print (which it does).

I initiate filament changes whenever I want by simply cutting the filament ahead of the extruder.  When the filament sensor triggers - the MK3S does it's own thing - parks the bed at the back of the Y stop, and moves the head to the stop at the far X, and starts to beep ("feed me"). Nice prompts on the control panel - click to unload, verify unload successful, insert filament, verify color change is good, after which it resumes.

I originally tried "pause" from Octoprint to initiate a "unload filament" sequence - but that was not good because the head doesn't move away from the print.  You can try moving Z axis if you're quick, but repositioning back afterwards was not easy and often caused failed prints.  

So if you want to change filament without the M600 GCODE in your print file - just cut the filament ( cut it at an angle).  I can even judge where in the print the change occurs by cutting nearer or farther from the extruder.  It's like a timer fuse.

RE: Octoprint and Filamentsensor

@4-unique-dogs

I save all of my files on the RPI.  No issues as all.  Which printer do you have?

I upload the file via wifi to my RPI and hit print.  It just simply works.  

RE: Octoprint and Filamentsensor

@cwbullet

I am currently using an Artillery Sidewinder X1. I will get my MK3S+ in the next few days.

I did some research and found this to be a most common problem with Octoprint. There are tons of articles about it.
I've already read that it's the same with the Prusa MINI.
Here: Prusa Mini ignores Filament sensor with Octoprint – User mods - OctoPrint, enclosures, nozzles, ... – Prusa3D Forum (prusaprinters.org)

If a Gcode is saved and printed directly on the Pi, Octoprint doesn't care if the sensor is triggered. Octoprint receives no feedback from the board and continues to push the Gcode to the printer.
A workaround is to save the Gcode on the printer's SD card and then execute it from there. Since Octoprint does not send the Gcode to the printer, but the board processes the Gcode, the sensor also works.
On the Sidewinder I branched off the cable from the sensor to the board and connected the GND and signal to the GPIO of the Pi.
With a plug-in on the Pi, the sensor now also works. Because it is plugged into the board at the same time and gets the 3.3V from there, it also works when I print without a Pi.

Nice to hear that this is not the case with the MK3S.

RE: Octoprint and Filamentsensor

See this topic for more info. I posted pictures from a filament run out printing from octoprint. (10th post)

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-user-mods-octoprint-enclosures-nozzles-.../which-smart-features-of-the-mk3s-do-you-lose-if-you-use-octoprint/#post-418786

I think you can copy files from octoprint to the sd card. But it is extremely slow.

RE: Octoprint and Filamentsensor

@baklin

Thanks!
Thats exactly what i'm looking for 😀