I ran into a strange situation. After printing some ABS on the left nozzle, I attached the laser module. During the startup checks, the left nozzle was jamming when trying to retract upwards.
I removed the laser and the hot end, and discovered pieces of a white tube-like material above the hot end, which was causing the jam. After removing it, the nozzle now moves up and down normally—so that’s good.
However, I’m now concerned that something might be broken. Could this white “tube” be an actual part of the printer, or is it more likely to be filament that’s built up or deformed over time? Should I just try to fish out any remaining bits?
Anyway, I’ve opened a support ticket, but curiosity got the better of me, so I also had a go at disassembling the printer. It looks like the issue was indeed a bit of PTFE/teflon lining from inside a metal tube that’s part of the extruder filament guide. It had slipped out and jammed against the filament cutter, I suspect its function is to insulate and allow for reduced friction, it’s the only plausible explanation I can see as it’s defiantly a tube lining, and it’s held in place with the bottom of the metal outer tube slightly tapered, I guess it got soft while the printer chamber was hot the past few days printing ABS and just slipped out or broke up fragments and snagged!
After removing it, well whats left of it! the filament guide now springs up and down as it should. However, I suspect some PTFE/teflon fragments may have ended up in the nozzle—so that’s probably going to be trash, as it’ll likely jam again.
I think I’d better also wait to see what Bambu support says, but for now I’ll just stick to using the right extruder. That’s one of the perks of a dual-nozzle system, I suppose!
Because there is no tube in THERE I assumed it has to come from somewhere.
With no white plastic in the assembly either it can only come from above - IF it is a tube or remains of a tube.
And well, I did state that I have that I don’t have a H2D here but never mind I deleted that part.
Case closed.
If it’s damaged you can buy replacement H2D PTFE tubes in the bambulab store. They have a star pattern on the inside diameter, so you don’t want to replace it with some random PTFE tube from aliexpress or amazon which wouldn’t have that.
Whoa, do you have a picture of that? That sounds awesome and maybe something to help with other machines. Is the overall dimension still ID 2.5mm / OD 4mm?
I’m basing it on what was said in CNCKitchen’s interview with Tao (the really long one you can find on youtube). IIRC, they discussed it, with CNCKitchen “noticing it” and then bringing up the topic.
I assume it’s this one, which is currently in stock (at the US store, at least):
If the OP decides to replace his, maybe take a cross section before tossing the old one and post a photo of what it looks like? It would only take less than a minute.
I don’t know why they’re not selling it even now, but it looks like they’re facing quite a lot of manufacturing challenges (e.g., grid plates for laser, upgrade kit for laser, rotating dimension tool for laser, general h2d qc issues, petg hf qc/availability issues)…
Ordinary scissors will deform the tube by crushing it as they cut, whereas that happens much less with these $2 specialty cutters. I’ll go out on a limb and say that probably everybody (or nearly everybody) with a 3D printer should own a pair for cutting PTFE tube. That, or a pex tube cutter also works great.
