Filament Sensor of my Prusa MK3S is not working
Hi together,
I have an issue with my filament sensor since quite some time ... Now I ran out of filament during prints twice already and I think it definetely is time to adress this issue.
What happened? Well, the sensor was working fine after I built up my printer. But after a few weeks I had a cloaked teflon tube and had to use some force to pull out the filament. Since then the sensor was not recognizing any filament entered.
What did I check already?
- The light sensor seems to be working. When I block the path of light it is recognized by the software ... so electrically everything seems to be fine.
- The lever is moving freely and the magnetic force feels similar to the beginning.
- I replaced already the PETG lever (FILAMENT SENSOR LEVER BL MK3S MK2.5S) and the PETG filament guide (ADAPTER PRINTER BL MK3S MK2.5S)
But still the lever seems not to move far enough to block the path of light of the sensor. I already tool the upper part of the extruder apart but didn't find any broken parts. The filament guide was worn down on one side already quite a lot (I use abressive filament quite often) and I was sure I found the problem ... But after putting everything together, the sensor still does not work. 😐
I can use my printer without issues when switching off the sensor, but I really want to reenable this feature to avoid 24+ hour prints with ran out filament the last 30 minutes 😥.
The next thing I can think about is completely replacing all plastic parts of the upper extruder and maybe also replace the sensor itself ... But maybe I am overlooking something.
Did anybody of you have a similar problem and a solution to it?
Any suggestions would be welcome.
Thanks a lot and best wishes,
M.J.
Best Answer by HeneryH:
Loosen the cap where the sensor is and fiddle with the positioning. I needed a shim under the cap to make it work.
The design of the 's' model is just too close to the margin of not working. I think the 's+' model tweaked the design to make it more forgiving.
- Made by me -
RE: Filament Sensor of my Prusa MK3S is not working
I got this error after four months of operation. It can be remedied by installing the sensor board at a slightly elevated height using a washer.
I found this suggestion at Thingiverse: https://www.thingiverse.com/thing:4665750
RE: Filament Sensor of my Prusa MK3S is not working
I had a filament sensor that just would not trigger (manually tried to trigger it) and one that just needed parts reprinted. The manual triggering is how could tell in the sensor section is how I could tell the difference. If it does not register as a 1, replace it. I keep a couple of $8 sensors on hand from China to replace them.
The other option is to order the Mk3S+ upgrade kit. I would recommend the latter if you have not done that yet.
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Chuck H
3D Printer Review Blog
RE: Filament Sensor of my Prusa MK3S is not working
Loosen the cap where the sensor is and fiddle with the positioning. I needed a shim under the cap to make it work.
The design of the 's' model is just too close to the margin of not working. I think the 's+' model tweaked the design to make it more forgiving.
RE: Filament Sensor of my Prusa MK3S is not working
oh, and while fiddling with the cap, you can see the read value in some diagnostic screen on the front panel. It should flip 0/1 depending on detection.
RE: Filament Sensor of my Prusa MK3S is not working
@heneryh
That is a great point. I know there was an issue posted to the forum with the screw attaching the circuit board being too tight also.
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Chuck H
3D Printer Review Blog
RE: Filament Sensor of my Prusa MK3S is not working
I was fiddling around with the position and figured out that with some pressure pushing it to the left side (seen from printer front) I was able to make it work. Unfortunately I was not able to screw it down in a reliable manner. So I grinded off a little bit of the lever .. just 2-3 tenths of a millimeter .. Now it is working ... Haven't tried yet with softer filament (i.e. TPU) ...
I ordered an MK3S+ upgrade kit already beginning of December last year ... So I will see what improvements it will bring as soon as it arrives. 😀
Thanks for your support ... Great community
- Made by me -
RE: Filament Sensor of my Prusa MK3S is not working
@m-j-caboose
Good to hear. I may try that with one of mine. It works intermittently.
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Chuck H
3D Printer Review Blog