Today I was trying to print the first layer over the entire build plate, and I ran into a problem: the printer gave me an error saying it couldn’t change the print head. I’m attaching a photo as an example.
I then tried to unload the filament from the left head, but that also failed. Currently the filament is still loaded and I can’t pull it out.
I followed the instructions and got to the step where I’m supposed to remove the front cover, but I can’t remove it because I can’t push the lift module (marked in yellow) upwards.
You should switch from left to right nozzle for the left nozzle to lift up. There are 2 ways to do that, one is to swing manually the flow blocker to the left or (the easiest ) is to power on the printer, go into the menu, click on « nozzle and extruder » and select « right ».
If there is a real issue that you can’t do it this way, then you have to swing the blocker. To remove the filament guide, remove the right hotend as well.
I can’t do either option. Simply put, what I found is this: the filament cutter cut the filament, but it remained inside along the entire length up to the extruder. The mechanism won’t move. The extruder can’t push the old filament out upwards, and I don’t know why.
Here you can see the extruder gear trying to move the filament, but it doesn’t succeed.
Moving the blocker to the left side works, and removing the hotend also works. The extruder motor works without any problems when switched to the right side. But after returning the blocker to the right side, the extruder still can’t pull out the filament. (left side) Where is cutter on left side is steal dont moving
So in the end I realized there are actually two systems that aren’t fully linked together: the blocker with the hotend lift, which also lifts Dual Extruder Filament Guide.
My problem is that the part that is supposed to lift the Dual Extruder Filament Guide does not move. I’m referring directly to the guide about the Dual Extruder Filament Guide this component: link.
Another issue is that my part is missing one hole and screw.
Basically, at the start my extruder couldn’t switch because this part wouldn’t let it lift up. I can’t remove this part because the instructions say it should be lifted, but it just won’t move. So I really don’t know what the hell to do with it.
Picture from heat bed you can see filament there
Replace H2D Dual Extruder Filament Guide | Bambu Lab Wiki
The extruder filament guide comes in versions with three screws and four screws. If the original extruder filament guide differs from the new one, before installing the extruder filament guide, first install the extruder right hotend connector located beneath the extruder filament guide.
Contact support , is the next best advice i can give you and explain your situation ,with that said the maintenance wiki should serve you well, just be careful
I did it once. I kept the right nozzle selected (left nozzle in up position). When that done, I pulled out the filament guide while pushing on the left lever. It need a little force to get it out, I first unclipped it on the right then on the left and forward.
You also need to remove both PTFE tubes and cut filament on both side by pushing in each cutting levers.
I had a somewhat similar issue—see my post “I Hate Jams.” In my case, the filament cutter jammed on what looked like a thin PTFE tube inside the metal guide. Initially, my filament got stuck, but I managed to free it. I suspect the tube actually helped prevent the cutter from digging into the filament too much.
You won’t be able to remove the filament guide plate while filament is still present, so it’s worth checking whether the cutter has fully severed the filament. If you can’t push the spring plate up, the cutter might be snagged.
You might be able to drop the spring plate by removing the hex screw in the oval-shaped hole. However, the cutter sits inside the plate and may not have enough freedom to move. You may need to remove the hex bolt holding the cutter arm—but that’s something I’d recommend confirming with support, as there’s likely a proper process for disassembly.
In my case, I also got a replacement filament guide, but I couldn’t tell if it had a PTFE tube inside or not. Everything works fine now, but it’s still a bit of a mystery where that tube came from.
If you can confirm the filament has been fully cut, try retracting it—then you should be able to remove the plate. Easier said than done, I know, but that’s the best advice I can offer from a similar experience. Tech support usually responds within a day or two. In the meantime, I just used the right-side nozzle But I was lucky mine was in the up position to start. I hope you get a resolution soon.
Good observation about the cutter — this is my photo. It’s very likely jammed because it doesn’t move smoothly from the start and keeps getting stuck, so there’s probably something wrong with it. That little spot I see there, I can’t tell if it’s PETG filament or something else.
I already submitted a support ticket this morning, so we’ll see what they say. But honestly I’m worried they’ll tell me to force it apart, because I don’t really see another way.
I also can’t remove the filament even when I switch the extruder to the right side — it seems almost glued in or stuck on something. I don’t want to pull too hard because I’m afraid of damaging or bending the linear rail. Basically, I’m really at a loss here.
As you seem able to push the filament cutter paddle in, it looks like the cutter may not be properly engaged with the lever. The action — pushing the top of the lever — pulls the cutter away, which is the opposite of how most cutters I’ve seen work. Essentially, the filament passes through the middle of the holder, and the blade slices from the opposite side.
I wonder: if you undo the grub screw in the front middle cutout window area (the one that prevents the spring plate from falling out the bottom), could you remove the spring plate — and possibly the cutter tool along with it — without needing to remove the lever? You’d need to hold the lever in while doing this. It does depend on whether there’s enough clearance underneath, of course, but this approach would be less risky for the machine overall.
You might also be able to observe through the small round hole on the left in the plate to check whether the lugs are properly engaged with the lever hooks.
If the assembly does come free, there’s a good chance you’ll be able to retract the remaining filament and finally remove the plate — assuming that’s what’s causing the jam.
Just a thought while you’re waiting to hear back from support. but im not an expert so only try what you feel comfotable to do.
As expected, the problem was with the cutter and its malfunction.
After some effort with pliers and a bit of “love,” I managed to release the filament so the Filament Guide could move upward, allowing me to remove it and pull out the filament.
I replaced the blade and reassembled everything according to the instructions.
I’ve requested a replacement blade from Bambu Lab, since the issue wasn’t caused by me.
Now, a bit of my own feedback:
The complete extruder is interestingly engineered and designed. The only thing I don’t like are the FFC cables, but I understand why they had to use them.
However, what I really don’t like is the support.
I moved from a Prusa MK3S+ to Bambu Lab, and I have to say this is an area where they really need to step up—by miles.
Waiting 3 days for a support response is just not acceptable—I expected more. I don’t blame people who choose Prusa over Bambu Lab because of this.
And honestly, I don’t understand Bambu Lab: if they offered online support like Prusa, they would gain many more customers and completely beat Prusa in every area.
Anyway, we’ll see how long it takes them to respond regarding sending a new replacement blade. I’m curious and will share an update.
