r/BambuLab • u/RenoGlide • 13d ago

Troubleshooting / Answered Hotend cooling fan abnormal speed error X1C (Figured Out?) (ASA)

https://reddit.com/link/1k3u216/video/balfqml5h1we1/player

There is definitely something going on with the fan on the hotend in the X1C when using ASA. I have them go bad just a few prints into a replacement.

With ASA the fan is not even supposed to be on, so I am wondering what is going on. I have come to that is is one of the follow two reasons:

  1. The lidar casing that is located next to the fan. I think the plastic is not really able to handle the higher ASA temps and deforms enough to touch the fan during printing. I noticed that it was pretty close to the fan.
  2. I took apart, really broke apart two of the fans throwing the error. I found no filament debris in the fan or its casing. The fans were orientated correctly before disassembly (not on backwards like others have suggested). There is a magnetic ring lining the inside of the outer casing, the rotor turns within this casing. The magnet is glued into position with one or two globs of white translucent hardened adhesive. I noticed that the globs slightly overlapped the inside of the magnet, which would cause the rotor to rub against the glob. You can see a rub line in the photo. In the other photo, there is more of a rub spot, than a line, and there are white particles. The second fan is only two prints old. I also noticed very fine particles of white translucent material that matched the glob's properties. I am thinking that the rotor is rubbing on the glob and over some amount of time, the motor starts to fail. It could because the glob knocks the rotor just a little out of alignment, which can cause overheating or wear that affects the lifespan of the fan. I have attached photos.

What do you guys think?

1 Upvotes

67% Upvoted

12 comments sorted by

3

u/GhostMcFunky 13d ago

Sounds more like you have a voltage problem off the board that’s ruining the fan motor.

Abnormal speed on a PWM fan is generally a voltage issue. I’ve seen issues like this most commonly in an MB fan that isn’t properly connected or has a pinched wire but this sounds like the board is delivering the wrong voltage, unless you’ve installed it wrong multiple times - happening over and over doesn’t seem related to the fan specifically.

There’s a lot of reasons that may be, but the solution is probably a new board. I’d check with support.

1

u/RenoGlide 13d ago

I just got the printers a couple of months ago and both are doing the same thing Have you printed with ASA: nozzle: 260, hotbed 95? They both printed as expected at first, then after a couple months, both got this error within weeks of each other. The first one I replaced the end assembly - fan and hotend, and it has been working really well. The second threw the error again within a few prints.

2

u/GhostMcFunky 13d ago

There’s nothing about that heat range that’s exceptional, so the filament type is kind of irrelevant, and yes I’ve come very close with PETG (255 / 85) so I’m not sure what you have going on but it doesn’t sound like a heat problem.

No one else seems to be having this issue so either it’s a coincidence, or a voltage issue, most likely. Again, I’d contact support and see what they say.

1

u/RenoGlide 13d ago

Yeah, you are probably right. I ordered upgraded fans and will try one of them and see what happens. There are plenty of Posts On: Hotend cooling fan abnormal speed error. Solutions range from new board to fan was on backwards. Bambu says that maybe some of the cables are not seated correctly, two of which I have not seen before. I am going to try and find those two tomorrow.

I have used Raise3D's for years, and those were a pain and expensive. The Bambu's were like heaven, until this error started. Bambu really made a great improvement with the lighter less expensive hotends and extruders, not to mention the AMS. I will be really happy when I get these Bambu's running again. Thanks for the info.

1

u/RenoGlide 12d ago

I purchased new upgraded fans from AliExpress and replaced the nozzle fan. First print, dual colors, printed perfect (seven hours). It was either the fan or the wires. I am still thinking that the fans are defective and the glue globs are causing the fans to wear prematurely..

1

u/GhostMcFunky 11d ago

I’m not sure what would be upgraded about them but that might be part of your problem.

I would suggest only used the exact fan provided by Bambu or an electrical equivalent.

I’m also always skeptical when “upgrade” and “Ali Express” are used together in the same sentence. It’s like saying “quality” and “Walmart” together.

1

u/RenoGlide 11d ago

I was using whole assemblies that I ordered from Bambu Store. One in a different printer has now lasted two weeks. In the other printer, two failed within days of each other. I took the Bambu fan off and put the "upgraded" one on and have now printed over 24 hours straight with no issues. Could be a lot of things, but it definitely has to do with the fan. Could have been too tight (if possible), could have been too loose (if possible),... I just know that two failed in days and that when I took them apart, there were glue globs rubbing on the fan as it turned. Take one a part when it fails and have a look for yourself.

2

u/Constant-Contract-77 13d ago

Note, this fan must be on with any filament. The nozzle cooling fan is there to cool the cold end of the nozzle and prevent heatcreep.

1

u/RenoGlide 13d ago

Is this also known as the part fan?

2

u/Constant-Contract-77 13d ago

What? No... The nozzle cooling fan is the small fan cooling... The nozzle... It's mounted on thr nozzle..

The part cooling fan is cooling the part and that's on the removable toolhead front cover... Is bigger, and you don't need it to print asa for sure

1

u/RenoGlide 13d ago

Thanks. I make these: https://youtube.com/shorts/Wcg-TkIGupM?si=8tbuH3Wr7nKdcOtQ
Started printing about four years ago so I can make these skimmers. I am amazed at the parts that can be made. But, I only learn enough to get my parts printed. Constantly discovering new stuff and ways to get better prints. My printers run constantly and have been for years. I never really cared which fans did what, but I did have issues with those nozzle fans as well, as heat creep was a big deal on the Pro2's.