At this point, I’ve tried raising the nozzle heat, the bed temperature, cleaning the plate with soap and water, changing the PTFE tubing, making sure the filament spool is dry, and using an alternate ABS filament color. I have also ran the calibration for leveling the bed and the flow calibration without issue.
I even swapped out my previously used nozzle for a brand new nozzle. I am at a loss as to what steps I can take next to fix this.
None of these have resolved the issue and this is my third attempt with the print. I do have a spare PEI textured plate I can attempt with. The machine has run for about 900 hours on primarily ABS for the majority of those hours. The ABS is Bambu’s ABS white filament or black filament.
Are you monitoring the temperature inside of your printer. ABS should be on the warm side like temps should be greater than 35C.
But most important. It definitely looks like temperature related. Have you tried another spool of another manufacturers ABS just to rule out a defective filament?
Also, if your nozzle was recently serviced, did you check to make sure that the silicon sock was clean and intact. Also, inspecting the thermistor is not a bad idea. If you’ve got backed-up filament creeping underneath the silicone sock, it may have also gotten in between the thermistor. Normally this would be reading too low of a temperature. Cleaning the whole nozzle is not a bad idea.
Check out this YouTube video on Bambu’s channel it may help.
You didn’t mention that you tried the troubleshooting techniques outlined in the Bambu Wiki but here are two that come to mind if you haven’t already tried them.
Here’s one on hot end maintenance.
Here’s a good Wiki page from Bambu describing how to clean the nozzle. Although it likely is not what’s causing your issue, it does show you how to tear down the nozzle assembly.
You didnt mention that you checked the belt tension.
I also print with ABS only also. If i saw that failure. I would do a full maintenance with a full calibration and a reboot after the calibration.
Manually move the x carriage front to back to see if it has any tight spots especially on the x axis. Clean it with IPA till it is smooth again if it has tight spots.
Make sure your new nozzle is torqued tight. Some users has seen them little screws come loose after a change.
I have been monitoring the temperatures consistently, it has been reading at 40 C on average.
I have not tried other manufacturers spools, I don’t have any on hand. I only purchased Bambulab filaments for the AMS recognition functionality. I’ll give checking the thermistor a go, the silicone sock was clean without any visible damage as well.
I’ll try cleaning out the nozzle and extruder again just to be sure.
This is what the print looked like after letting it continue to run for a few hours into the night. I paused it at this point to decide what to do next.
@Barryg41, I have not checked the belt tension yet so I will give that a shot. Thank you for mentioning it. I’ll also move the carriage as you’re mentioning and check on the torque for the nozzle. I had run the calibration and reboot as you mentioned, but only did the nozzle swap for a new one, cleaned the extruder, and changed the PTFE tubes as a sanity check.
Yeah, that’s what I was afraid of. If you look at posts here in the last 60 days, there have been numerous reports of Bambu filament problems. Some of these include color changes and performance differences for the exact same part number. The conclusion most of us have drawn is that Bambu is having problems with their supply chain and are changing production houses. So, don’t assume that just because this spool has the Bambu name on it that it was made with the same process or ingredients from the last time you purchased it.
Look to see either the date codes or batch number. But truth be told, the only real test would be to get a spool from an entirely different source. It’s the only way you can be certain that the spool is different.
Also, I just realized your feeding this through an AMS. Have you tested it outside the AMS? Wouldn’t it be a kicker if the entire issue ended up being in your feed path. At least it’s something you can eliminate as a variable.
I will run a test with some Creality filament that I discovered I had in my workshop, didn’t realize I had it. Its an ABS hyper Creality spool, so I’ll run that test later today.
Using the Creality ABS spool I had along with a comprehensive maintenance cycle seems to have resolved the issue. In the maintenance cycle I did the following:
Belt tensioning
Carbon rod cleaning
Self-test after the above two steps
Bed leveling long screws regreased after cleaning
Side fans and hot end fan cleaned
PEI textured plate cleaned
Lidar camera lens cleaned
Camera lens cleaned
Filament cutter replaced
Nozzle cleaning roller replaced
Activated charcoal filter replaced
Hot end, extruder, and nozzle disassembled and cleaned
Here is a multiple day print in progress using the back spool holder and the Creality ABS spool I mentioned above:
So far it seems like it is working as expected. It makes me wonder what to do with the Bambulab ABS spools I have now…I’m hoping someone from the Bambulab customer service team sees this and can advise me on what to do with the spools I have. I have around 10 spools of their ABS filament and I’m not sure if I can trust them to work given the previous experiences in this thread.
That’s all well and good, but it may not prove that your troubleshooting methods were the remedy. Did you first try the Creality filament before making changes to the machine? If not, how do you know what solved the issue?
To put this to rest, try the Bambu filament again. If it functions, the machine was at fault. If it fails, the filament was at fault. Without a proper diagnostic method, changing two variables at once can obscure the root cause and give a false sense of having fixed the problem. If it happens again, you won’t know which part of your remedy was effective.
