To quickly fix a jam, I replaced the extruder and hot-end on my X1C with identical parts from the Bambu Lab store.
The new extruder came with a small tube of silicone glue. I presume it’s the same stuff that had glued the printhead electrical connectors in place when it was originally built at the factory. i.e. the same stuff that made disassembly more difficult this time around. I can understand why it was put there in the first place: to avoid disconnects during shipment and delivery of the X1C, and also because of all the vibration that hapens during calibration/printing. That said, whenever the next jam happens, it will make the next disassembly difficult all over again.
Are you all re-gluing it, or not? And if not, has not re-gluing it ever turned out to be a problem for you?
When you removed it, did you heat the glue up first? I think you are supposed to use a hair dryer or something to soften it to make it easier to remove.
I have pulled mine on\off a ffew times cleaning\inspecting extruder, i dont have any of the glue- done about 120 hours without glue now. I would love to know an aftermarket brand\name of the stuff to reapply. but it hasnt hurt me so far with out it.
To remove to glue easily, I used long needle nose tweasers and gently just pried it off section by section with gentle heat. I still managed to damage one connector (ripped one off the side tabs off) thou even doing that … so your not wrong.
I wouldn’t bother. If you ever get an error related to the printhead, push on the connectors to make sure none have worked their way out. But they go in with sufficient friction, even with a large number of thermal cycles, I don’t think they’re going to “walk”. I think you’re (much) more likely to remove it again for some other reason like a clog, long before the connectors could disconnect because they’re not glued.
When I did my first hot-end removal, I asked myself why they’d bothered with glue. And I do electronic stuff for a living, so my judgement was based on prior experience vs. just guessing.
When changing nozzle sizes you are ALWAYS unplugging, plugging in the connectors. I do a lot of nozzle swaps (0.2, 0.4, 0.6 sizes), and I don’t put the silicone glue back on the connector to the board. Too much of a pain to reapply and get off. I have hundreds of prints done without any silicone glue on the connectors with no issues.
Just make sure to turn off the printer before unplugging any of the nozzle connectors (heater, fan, thermistor). Then just make sure the plugs a properly seated when plugging them in. Then turn on the printer.
That’s a good suggestion. Neither the wiki nor the BBL youtube video on extruder disassembly made any mention of glued connections (or, if it was mentioned, I totally missed it). Consequently, my initial impression was that the printhead must have overheated, causing the connectors to literally melt into one another. I used a couple of tweezer pliars to separate the connectors. It wasn’t until later that I opened up the new extruder box and saw the silicone glue.
It was thanks to this guy’s video that I became aware that the pin connectors are just surface soldered to the PCB, not even through-holes as they should have been:
That said, I don’t think the poor guy ever realized that the connectors had been glued together, because he made no mention of it either. It’s probably what led to his downfall.
Aaaaa… They forgot that there are release tabs on Heater connector (big white wires) and the thermistor connector (2 black wire) that have to be depressed while removing.
The fan connector (1 black, 2 gray, 1 white, wire) is a friction “snap” connector.
I just use small needle nose pliers and gently depress the tabs and pull off connectors. The fan connector is again gently grasp and pull off.
If you look on the other boards in the printhead you will see that Bambu also uses hot glue on those connectors (one example I remember was the Lidar connector).
Yeah, I’m sympathetic to their mistake: it’s hard to see tabs, or even know they exist, when they’re covered in glue. It was thanks to their video that I knew to be extra careful to avoid damaging the pins or the pcb traces where they had been surface soldered down.
Had BBL had the foresight to realize some of their customers would not have the experience to properly remove these connectors, maybe they would have decided different.
But there is nothing fundamentally wrong about SMT connectors. They’re very common. Not having to punch vias through a multilayer PCB, especially for connectors in the middle of a board, can make routing significantly easier.
The USB connector in your cell phone is probably a surface mount connector.
The problem is that you can’t yank on surface mount connectors as hard as you can for through-hole. Which makes them susceptible to damage from inexperienced users.
Some of the earlier instructions, wiki etc, until cautions added - advised to ‘hang’ the hotend off by the wires, using a pin tool to clean etc. Unfrotuantely, this resulted in may reddit and other posts of broken cables as it was simply too much force and the sudden “Release” usually resulted in a sharp jerk on the wires.
Bambu does try and ensure people be careful, but yeah instructons basically hanging off the surface mount and exerting force, was never going to end well.
This sounds like very useful new information that I haven’t yet seen anywhere else.
Thanks everyone for your comments, analysis, and sharing of your experience.
It sounds as though the majority advise not to re-glue, and I find myself in easy agreement with that.
Even though my X1C is now my go-to machine, as a Prusa MK3 owner I’m deeply appreciative how that design got refined over time and official upgrades made available. IMHO, I think that approach is a big reason why people developed trust for that brand. I hope BBL will consider doing the same for the X1C, or, if not, maybe giving that opportunity to Panda or E3D or Duet or some other collaborator if BBL doesn’t have the inclination or the bandwidth to do it themselves.
Before today I hadn’t known that such a tool existed! Because of the glue, better still would have been a “JST Puller”, which, if it exists (?), would work similar to how either a battery terminal puller or a gear puller works. i.e. it would safely force apart the connection without running the risk of ripping the soldered connector off the PCB.
I used a couple of tweezer pliars to separate the connectors. It wasn’t until later that I opened up the new extruder box and saw the silicone glue. 
It was thanks to their video that I knew to be extra careful to avoid damaging the pins or the pcb traces where they had been surface soldered down.