Since most Bambu Lab printers are the same age, I can imagine
that this problem could affect several people here in the forum.
My printer has been producing imperfect prints from time to time lately.
After 3 weeks of vacation I wanted to use it yesterday and this is what I got as a result:
So I cleaned the nozzle according to the instructions and was in good spirits when the next print looked pretty decent at first glance.
When the printer stopped extracting filament after a few cm height (unfortunately no image), I cleaned the nozzle again.
Then I remembered that I had already seen similar prints here in the forum.
So I removed the hotend and took a closer look.
The reason for the bad prints is so simple that it made me laugh:
The THERMAL GREASE had hardened.
There is a thin layer of thermal grease between the hotend and the ceramic heater for better heat transfer.
This was dry and crumbly.
So I cleaned the hotend, ceramic heater and thermistor with a dry sponge.
This was quick and easy. You just have to make sure that there are no remaining hard paste hiding in any cracks.
Then I applied fresh thermal grease (supplied with the spare parts).
More is better.
had the same issue and i switch to thermal grizzly Kryonaut extreme for the thermal compound, it made a marked difference. the hot end heats up quite a bit faster and temps read better. not sure it will last as long but ill post if it drys out and fucks up the hot end lol
The boron nitride is supposed to be the best for high temperatures, I tried some arctic silver left over from my overclocking days and it went dry and powdery after a short while.
Slice engineering is about the only easy place I could find BN paste to buy.
I bought the X1 Combo in January 2023 and printed +/- 15 kg of filament. It started two month ago with problems from time to time. When the printer was getting warm, the prints were better.
I can’t help but scratch my head when I see ASI 388 as their reference pic for the wiki page on replacing the hotend. I honestly hope that’s not what’s being used.
I guess we’re all sitting with these time bombs waiting to go off?
If I ever go through the bother of refreshing the thermal paste like the OP did, I don’t want it to become a regular thing. Is there a guaranteed once-and-done fix for this? Is the Slice Engineering BN paste that solution, referenced above, or is there something better?
I don’t think there’s a ticking time bomb, but I could be wrong since I don’t know what Bambu Labs uses and maybe it wears out over so many heat cycles. I personally use the Slice Engineering Boron Nitride thermal paste. It is supposed to dry out before full use, so seeing that Bambu’s paste did the same thing isn’t surprising. Boron Nitride is very different than what you’d use on a PC and needs to fully dry before it becomes non conductive.
The Slice Engineering stuff is supposed to work up to something like 1000C, so it’s arguably a great option. I’m not aware of it ever going bad or at least I haven’t been able to find anything in regards to needing to reapply after any amount of time, except when replacing parts.
Boron Nitride - Non-conductive when dehydrated at 100°C -
I wouldnt see the need to do this prior to application in on a 3d printer - my thermister and heating element have insulated wires and are held down onto a metal surface by a square metal wrap. I’d imagine all of that is conductive.
Instructions say to apply directly, i dont know exactly what you mean by “dry out before full use”, but i’d imagine if your printing at over 100 degrees that it will become non-conductive after a few minutes after application.
i see some thermisters for bambu coming with this GD900 that is only rated up to 200 degrees, unsure what the little bambu packets are rated for.
