Melted filament sensor
My filament sensor melted into my extruder housing last week. I was unable to get it out in one piece. The extruder housing was a mess and parts of the issue must have gotten into the extruder as the filament had stopped. I have repaired the filament flow and need to work on replacing the extruder housing but I would like to get a new filament sensor. I sent a message to Prusa last week about my problem and as of today I have not heard back from anyone. The upgrade had worked very well up to this point. The machine was in the middle of a 12 hour print when it failed. When I returned I found the print head melted into the print and the smell of burned plastic. I removed the print from the print head and found that the filament had stopped flowing. I finally found the issue but when checking the error messages there were none. I'm guessing I had a power failure while I was away that might of had something to do with the problem. I have read that others have had problems with the filament sensor but have heard nothing as to the resolution. Could someone give me the information needed to have my sensor replaced.
I3 MK2s upgraded to 2.5 this year
Original Prusa I3 MK2s with 2.5 upgrade; Original Prusa I3 MK3s; Slic3rPE; FreeCAD
Re: Melted filament sensor
This is really worrying to hear. I have the same sensor but I never thought it would overheat bad enough to catch fire. Please let us know if you hear anything from Prusa.
Re: Melted filament sensor
Talked to Michele today about the issue. Seems that they will be able to help me get a new upgraded filament sensor. I will have to print some new parts and will let you know how it turns out.
Original Prusa I3 MK2s with 2.5 upgrade; Original Prusa I3 MK3s; Slic3rPE; FreeCAD
Re: Melted filament sensor
Printed my upgraded extruder parts in Prusa Transparent Blue, installed the new filament sensor, re-calibrated xyz and put on my new print plate. Everything works well. I am even impressed with the PETG prints look as good as the PLA and both did extremely well with the bench test. Love the texture of the powder coated plate impression on the print. Just another satisfied Prusa customer.
Original Prusa I3 MK2s with 2.5 upgrade; Original Prusa I3 MK3s; Slic3rPE; FreeCAD
Re: Melted filament sensor
This is really worrying to hear. I have the same sensor but I never thought it would overheat bad enough to catch fire. Please let us know if you hear anything from Prusa.
➡ He didn't say it caught fire. It got hot enough to melt plastic, like you know, what a 3d printer is designed to do. 😆
Re: Melted filament sensor
This is really worrying to hear. I have the same sensor but I never thought it would overheat bad enough to catch fire. Please let us know if you hear anything from Prusa.
➡ He didn't say it caught fire. It got hot enough to melt plastic, like you know, what a 3d printer is designed to do. 😆
Okay, I admit, without knowing how it actually got into that state, saying that it "caught fire" might not be the best choice of words on my part. However, regardless of how I have expressed it, I am sure my concern still stands valid. While the printer is designed to heat up and melt plastic, I can't see how it would be a normal thing for a component like the filament sensor to heat up to a plastic melting temperature. That's just like saying that any electronic part (board, motors, PSU, LCD) in the machine can freely heat up to 100°C, 200°C etc (values are arbitrary chosen to express a plastic melting threshold) because that's what a printer is designed to do.
My concern still stands. I am still wondering if this is an isolated case or if any older version of the filament sensor is unpredictable and possibly a safety concern.
Re: Melted filament sensor
I was about to purchase an i3 kit, but seeing this has worried me enough about fire to hold off.
Is there any official communication from Prusa regarding fire risk with the filament sensor?
I suppose I could just keep it disabled. I have read a lot of issues with the sensor in any case.
Re: Melted filament sensor
I heard from Prusa on this one:
"previous version of filament sensor might overheat and melt the plastic parts around, but we tested it and the max temperature the sensor could achieve was never even close to auto ignition temperature of anything on the printer. Yes it looks bad as it smokes and melts the plastic, but it is not dangerous nor fire hazard.
We already fixed the issue, MK3 has new revision of filament sensor with fuse, so this problem can not occur anymore. "
Re: Melted filament sensor
I heard from Prusa on this one:
"previous version of filament sensor might overheat and melt the plastic parts around, but we tested it and the max temperature the sensor could achieve was never even close to auto ignition temperature of anything on the printer. Yes it looks bad as it smokes and melts the plastic, but it is not dangerous nor fire hazard.
We already fixed the issue, MK3 has new revision of filament sensor with fuse, so this problem can not occur anymore. "
Thank you. That's somewhat of a relief. I should get one of the new sensors then, don't want anything to melt. In my opinion they should have recalled the sensors and send appropriate replacements as soon as they knew about the issue.