I’ve had 3 nozzles fail now with leaking from near the top of the nozzle ( see pictures ).
Is there a known issue with nozzle fabrication quality that results in this failure mode?
H2D
0.4 WC nozzles
PA6-CF
< 500hrs per nozzle
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Where is the filament coming from according to you?
You might want to run it for testing without a silicone sock, to see where it’s coming from.
What filaments are you printing? In other words, at what temperatures?
I can imagine a faulty product, but 3 in a row, suggests that it’s highly likely another issue than the nozzle itself. AFAIK all nozzles perform a test run before shipping out.
From the image, the chrome seems quite yellow, have you heated it with a blow torch?
I have myself 2 Tungsten Carbide Nozzles in use also, but not seeing anything resembling your issue.
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He’s using nylon according to the post. I have not personally used mine enough to cause this, but I have read others on a different forum stating the tungsten carbides have separated/split on more than one occasion
The filament is coming from here, in all 3 failures (see attached image, which is a screenshot from a video)
the filament is PA6, at 300 degrees
Definitely no blow torch or “abnormal maintenance”
It has happened on more than 1 printer, and on both left and right nozzles (to help eliminate other factors)
Thats interesting - if you can point me in the direction of any other reports of similar failures, i’d be very grateful.
Thank you
Is it a mixture of friction and heat causing the nozzle to come away from the heat break/sync ?
You may find nozzles need changing more frequently with those filament types and better attention paid to the printing process.
This definitely seems like a design failure then.
I will be inspecting mine to see if I could get this also.
The higher temperatures seem to be the cause here then.
My understanding is that the nozzle assembly is a “press fit”. That being the case, the higher the temperature the looser that press fit is going to get. Really high extrusion temps could result in it getting too loose.
PA6 @ 300ºC seems kind of high to me. Ignoring the fact that it should work anyway, a temporary solution could be to just run with a lower extrusion temp.
If you’re running the PA so hot for flow, so that you can get to a higher extrusion speed, that’s going to develop higher pressure in the nozzle, and that could also be a contributing factor. Slowing down might help (or lowering the max flow in the filament profile).
I run PA at around 270º.
I noticed you are using .4, while it’s not listed as unsupported, .6 is the recommended size. It might be pressure/heat/friction all adding up causing the .4 to fail.
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The Bambu website states that the 0.4 WC nozzles are not compatible with PA6-CF.
Only recommended with the WC 6 or 8 nozzles. Nozzle temperature 260-300C.
My understanding is that the “compatibility” is usually because the 0.4 and smaller nozzles are prone to blockages with some filaments. I’m not running high flow rates, and haven’t experienced blockages.
The filament I am using explicitly provides a profile for Bambu printers with a 0.4mm nozzle. I.e. the 0.4mm WC nozzle is supposed to be compatible with the filament.
https://fiberon.polymaker.com/product/pa612-esd/
I’ve dug the 3 failed nozzles out of the trash and tried to diagnose where they failed - it appears that they’ve worn away from the inside, all 3 in the same location. They looked a mess because I used a small file to clear away the debris from the failures.
I had expected the nozzles to fail when the 0.4mm exit started to erode, not by eroding a hole through the side of it. Does the hardened inner tube not go all the way through the brass body of the nozzle ?
There might be conflicting information out there and it wouldn’t be the first time its happened on their website. The filament page doesn’t even cover the tungsten nozzles, and I found out that the .6 tungsten is not recommended for TPU.
Under recommended in the filament page it says this:
Hotend with Hardened Steel 0.4mm / 0.6mm (recommended) / 0.8 mm
Personally I would not use anything below the (recommended) but the heading actually says “recommended”. They need to be more clear so people dont have failures like this, especially on the more expensive nozzles that aren’t even covered. Shouldn’t have to check both the nozzle page and the filament page and hope they are both in sync.
That Is just wow. I would request they replace the three nozzles. While it’s not a Bambu filament, that is clearly not acceptable on a nozzle they advertise for abrasive filaments.
Correct, as I found out trying to clear a clog using map gas. The whole thing shot off across my garage as it released the compressive pressure due to the heat applied.