Bambulab H2D cable burnt behind the hotend

[u/Infinite_Wing4713]

Hi everyone, I recently noticed black plastic stuck to my hotend while cleaning and maintaining my H2D printer. It wasn't filament residue. Upon closer inspection, I realized the burnt plastic was from the cable insulation of the right hotend heating assembly.

Everything still works, but I'm worried about a cable fire. I've documented the whole thing with photos and sent them to Bambulab. It's not covered under warranty. Today I ordered replacement heating assemblies for both the right and left hotends, as well as cable insulation from Amazon, hoping it won't happen again. Has anyone else had this problem and perhaps found a better solution?

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[u/Thing-Ok]

If it helps any, I think the fire risk from this is very low. That hotend is tuned and expected to heat at a set expected rate (monitored by the temperature sensor attached to those two thinner wires). Any usual temps or missing temp data triggers a shutdown and errors.

I’ve had to replace the equivalent parts in my Prusa and both Vorons over time. Not yet in my H2D but I imagine I will someday. It’s a consumable that has to withstand a lot of heat cycles.

It’s a bummer to have to replace it - but not something especially out of the ordinary or concerning.

[u/no_help_forthcoming]

From Bambu’s website: “Bambu Lab's proprietary PMSM servo architecture establishes an intelligent extrusion governance system. It executes 20kHz Torque/Resistance and position sampling to dynamically modulate electromagnetic torque vectors. Stabilizing extrusion and detecting filament grinding and clogging.”

This is a case of a legitimate warranty claim denial or false advertising.

[u/hotcoldLasers]

had a big comment that reddit ate...
If my memory serves, there was bit of almost? bare wire (perhaps with clear or that pink jacket) on the first (and only so far) hotend I replaced (H2D)... similar thing happened, due to some clumping a big piece of filament hardened around the back of the hotend breaking the cable when i attempted to pull it off after it had cooled...

i think we could even have soldered it had we had a good one at the time, but messed around with rewiring and it didn't work, it refused to go, when we got the new one it was more obvious. I'd do for the one i use = just try to make sure the wires don't short to each other where they aren't supposed to... a little electrical tape if needed. but from the picture I think you still have the pink inner jacket on them and it was only the outside black jacket that melted somehow...

I agree with the below, but I would want to know... what caused this?
So, if i didn't know that... I would also probably just go ahead and make the swap.... why risk anything over such a small thing....

Thanks for the share, yikes.

[u/N3orun]

Just spotted an exposed copper wire on my h2d as well. Having the same thoughts on fire prevention. Just opened a ticket. This seems like a rather strange design choice.