Expensive mistake

Bambu Lab H2 Series
1

Well, it had to happen sooner or later. I had my first major screw up and nuked my left nozzle assembly in the process. I’m definitely a newbie to 3D printing, with less than a month total ownership time of my H2D, which is the first printer I’ve even seen in person.

I was printing flow rate calibration rectangles and everything was going fine through layer 4 of 7, but it was going very slowly, so I stopped watching and went to do something else in the room.

Then I got a message in Bambu Studio that the filament cutter had failed, and to please check it. Sigh, OK, must be this super-hard filament. Nope! Apparently shortly after I stopped watching the printer, something happened and the calibration prints got stuck to the nozzle. Not just one: the nozzle moved around and vacuumed up probably four or five of the things before “completing” the print job and trying to park the head, which failed because it no longer fit in the parking/purge spot due to all the junk hanging off the bottom.

Super. Alright, gotta get this massive lump of plastic off of the nozzle, no big deal - wait a minute! What are these wires embedded in the lump? Oh, I see: The heater wires all got pulled out and glued into this unholy black glob, which has also extruded up the inside of the silicone sock and completely encased the nozzle and lower half of the heater assembly.

Did this happen with PLA? PETG? Surely not ABS? Nay, it happened with PA6-CF, the toughest stuff I’ve ever printed with.

Thus began a two-hour ordeal where I used my temperature-controlled soldering iron to carefully melt through this mess and cut off tiny little portions until I could finally see the remains incased within. I was then able to very, very carefully solder the heater wires back together and command the heater ON at 300C, which finally allowed me to release the nozzle clamp and gingerly pull the nozzle out.

Think I can clean up the nozzle and reuse it, so just the heater needs replacement. The time lost, though! Turns out if there’s a fault on the left nozzle, the printer is dead. It won’t print from the right nozzle, no way, no how. I’m sure I could hack the machine start G-code to disable the checks, but down that path lies potential for serious equipment damage if I mess up the change and set home to somewhere next to the printer or something.

Ordering a new heater module off of Bambu’s store was painless, but only “standard” shipping available and then the order got sat on for two days (I did order on Sunday, so one of those days doesn’t count). Estimated delivery is Saturday, so almost a full week without my printer. Damage bill? About $40 for a new left-side heater module after shipping and tax.

How did this happen? Well, it’s Nylon, and I used the textured PEI build sheet the printer came with. No problem so far. Except: Didn’t use glue, nor did I wash the plate, which I had probably printed half a dozen things on since the last trip to the sink. The first is because I misremembered and didn’t think I needed to. The second is because I was lazy.

I think the “AI” should’ve picked up that there was a huge pile of trash stuck to the nozzle, but I can’t place all the fault on the printer as I missed using glue AND didn’t clean the plate, which I’m sure is why the print popped off in the first place. So frustrating.

1 Like
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Be careful with glue, as one mistake can easily lead to another. Make sure you read up on when and how to use glue! Its purpose is not always to make the filament stick better, but to create a separating layer so that it can be removed more easily. If you use it incorrectly, it will have the opposite effect. Unfortunately, this substance is called ‘glue’ - a more accurate name would be ‘release layer for easier removal to prevent damage to your printer plate’.

Please, before using the glue, be sure to read the wiki, otherwise you will have exactly the same problem again.

… and the data sheet for PA6-CF

As I said, I am NOT saying that you should not use glue, but rather that you should find out what the glue does in this case.

The temperature of your print plate is much more important - as is having your filament dried, because it is really sensitive to moisture. I’ll copy the tips from Sea_Plastic9920 for you.

____________

Printing with nylon can be a bit challenging due to its unique properties, but with the right techniques, it can produce strong and durable prints. Here are some tips to help you get started:

  1. Bed adhesion: Nylon tends to warp and curl during printing, so proper bed adhesion is crucial. Use a heated bed (around 60-80°C) with a layer of adhesive material such as PVA glue or a nylon-specific adhesive sheet. A brim or raft can also help with bed adhesion.

  2. Enclosed printing environment: Nylon is sensitive to moisture, so it’s important to print in a dry environment. Consider using an enclosed printer or adding a dry box or filament dryer to your setup.

  3. Printing temperature: Nylon requires a high printing temperature, typically between 240-260°C. However, the exact temperature can vary depending on the brand and type of nylon you’re using, so refer to the manufacturer’s recommendations.

  4. Slow printing speed: Nylon is prone to stringing and oozing, so printing at a slower speed (around 30-40 mm/s) can help reduce these issues.

  5. Cooling: Unlike other filaments, nylon doesn’t require much cooling during printing. In fact, too much cooling can cause warping and layer adhesion issues. Consider turning off the cooling fan or reducing the speed.

  6. Post-processing: Nylon can be post-processed using techniques such as annealing or vapor smoothing to improve its strength and appearance.

By following these tips, you should be able to print with nylon successfully. However, keep in mind that nylon can be challenging to work with, so it may take some trial and error to get the settings just right.

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I use glue with every filament I own—just not the same glue for every filament. I print everything from PLA all the way up to PPA/PPS.

So calling glue “a bad thing” doesn’t really make sense—unless the concern is that someone might use it incorrectly. By that logic, a 3D printer itself is pretty dangerous too. :grinning_face_with_smiling_eyes:

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Reading isn’t your strong suit, is it? I wrote that people should inform themselves. I didn’t say that glue is bad. I’ve never blocked a troll so fast. Bye.

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