Today, i was printing with a 0.6mm nozzle and some bambu PAHT-CF, when i heard a sound and noticed that the nozzle came of the hotend. It basically slid (Z-Axis) down the hotend and was hanging by the wires. I stopped the print, changed to a 4mm nozzle and printed a complex part with some PLA to see I had any other damage. Printer looks fine for now… I did file a ticked with Bambu support to see what they say…
I tried to look for any set screws, etc… but this looks to be a press or some sort of welded fit… anybody any thoughts?
Damn, that’s really unfortunate! I hope they can sort you out with a replacement. As far as I know, the hotend is press-fit, so there’s not much you can do to fix it yourself. Could it be a clogged nozzle? It seems unlikely that the extruder would push that hard, but it’s worth considering.
Chris, nozzle was not clogged (I believe), but it is hard to tell after the fact… the extruder should not be able to push the nozzle of the heat sink/hotend… i was printing paht-cf at 280C, for a few rolls, so the cooling/starting cycles may have had an impact. Having said that, the printer goes to 250c almost all the time when swapping filament… basically, it should never happen…
Common issue. It’s a design flaw they try to cover up. If you want something reliable go with an aftermarket hotend.
Issue.
Heatblock and or nozzle separation.
Cause.
Cheap materials, design flaw, poor quality control. The nozzle being hardened steel and the heater block being brass with a titanium heartbreak they all expand at different rates. Parts are a shrink fit and the heartbreak is a shrink fit with retaining compound. If the nozzle is oversized slightly or the bore in the heatblock is undersized when cooling after assembly it will develop cracks. It’s not out of spec for the parts of you ask Bambu there spec is anything between 0 and infinity just dapends on how they feel but it’s an issue with the tolerances of the parts along with the assembly.
Fix.
None
And yes. I did FPI on a nozzle along with pressure testing and microscoping inspection before cross-sectioning one.
This is why the A1 uses a different hotend. I haven’t cross-sectioning one of those But I’m assuming that they fixed it Because I let them know over a year ago about this issue with the X1 hot end and sent them all the data that I collected.
View of one of the 4 cracks on a new unused Bambu hotend. Out of the 6 I had 3 were cracked. And this is a view after cross sectioning after someone who handles their social media thought that they are an engineer try writing it off the scratch.
Just updating this post. I am now on my 3rd cracked/damaged Nozzle, and getting frustrated with the poor quality of these assemblies. It happens when printing PAHT-CF and each time using ESUN PAHT-CF. I am not sure if this is a coincidence, but the QIDI brand has not seen it.
Nevertheless, the BAMBU Nozzles should not fail especially when advertised for printing the PA-CF materials. So hopefully BAMBU is going to do something about their QA/QC… right now these nozzles are rubbish for higher end materials…
I noticed that the ESUN brand appears more Hygroscopic than QIDI’s and losing more weight during drying (in fact, QIDI does not lose any weight) and especially ESUN is oozing excessively and possibly building up more pressure… When I stop a print, at least 15 to 25 cm of material is oozing out. It could be the ESUN needs even more drying (I dry for 48 hrs at 70 Deg.C) and then print from the dryer directly. Also, ESUN filament thickness varies from 1.69 to 1.77 mm over a 30 cm distance… My main reason for trying to use it (little luck with 5 rolls) is the strength (on paper anyway). So no more ESUN PAHT-CF for me!
It fails because they are made cheap. The best thing you can do is pick up an aftermarket hotend.
The only ways they can fix this is by changing the materials of the hot end that won’t happen because it’s going to cost them more money And he’s hot ends are made as cheap as possible. Implementing magnetic particle inspection. Again they won’t do that because it’s going to cost more money. The only fix is to change to an aftermarket hotend because the failure rate of these hotends is very high because of how they are designed.
I have one hotend that ran PPS 20% cf with no issues. However that was not cracked. I had a new one out of the box that had 4 cracks in it and that would of failed.
It just happened to mine too, I’ve only had it since November 2023. I was running my 4th or 5th PA-CF part ever. When I woke up, the print had completed the program, but there was about 3’ of virgin filament inside the print chamber. I thought it had broken. But on further inspection, it just pushed off the end. It happened during printing, on the video capture you can see when it starts dragging the top of the part. I’ve had my filament in a dryer for weeks. It was printing fine when the nozzle came off. Anyone tried to press them back on? I have a machinists vice on my Bridgeport, I’m sure I can just press it back on. But there’s no way the extruder has enough force to push the nozzle block off. I think I’m going to try it. If it comes back off again, I’ll try some Red loctite first, then Rocksett.
Great job
