I’ve been facing unexpected issues with my X1C printer in combination with Bambu Studio slicer over the past week, and I’m struggling to identify the cause.
I’m trying to reprint a desiccant box model that I’ve successfully printed before using the same filament, but now the print quality is awful, and I’ve had to cancel every print attempt. UPPER_SPILLPROOF Grid AMS Desiccant Pods RECTANGLE.3mf (78.2 KB)
Here’s an example using Bambu’s PLA Basic White with the default PLA profile. Just a few weeks ago, this exact filament worked perfectly without any issues.
I’ve tested on both the textured PEI plate and the smooth PEI plate, and I’ve dried the filament with a dryer (polydryer). The AMS humidity levels seem fine (around 15%), especially since I’m only printing PLA and PETG.
While the first layer appears to print well, the subsequent layers exhibit problems.
It seems like an under-extrusion issue to me, but I’ve already checked and cleaned the extruder and nozzle for debris—they both seem to be in good working condition.
Additionally, I recalibrated the filament flow dynamics and re-calibrated the X1C multiple times, but none of this has improved the results.
Does anyone have any suggestions on what might be causing this or what else I could try? I’m out of ideas at this point.
AMS humidity levels can be deceiving. Filament doesn’t give up much moisture at room temperature. Some, but not wholesale like when drying.
Since water is slow to leave it, the desiccant can dominate the humidity measurement and lead to thinking filament is dry when it may not be.
A way to measure filament moisture content indirectly is to put a spool in a sealed container with a hygrometer and no desiccant. Then the filament moisture can equilibrate with the container humidity and the hygrometer can read that humidity after about 10 hours or so. It’s a slow test.
The reason I mention filament moisture is that looks a lot like what others post with wet filament, but even more, you say the print used to work and now it doesn’t. Unless you changed something, it should print the same minus wear and tear effects which I’ve never seen myself, except for something changing with the filament.
Bambu has changed formulations on us without notice and it did affect prints. But if those are the same spool as worked before, my money is on moisture. Additionally, I don’t think we’ve seen even one report of prints getting better from moisture except through drying. It always goes the other way - good prints, then more and more problems, then failed prints.
Might look more into drying but maybe it’s some odd clog or something not related to moisture?
I measure the humidity levels with a dedicated (accurate) sensor, so ignoring the AMS humidity levels. That sensor tells me the humidity levels in the AMS are ~15%. The rolls of filament going in the AMS I dried before putting them in.
Both rolls of filament have dried for 2x 6h per roll in the polydryer. So my reasoning was that they should be dry…
I will do another round of drying to see if it improves anything!
Should be and are dry are two different things. If you have a ziplock freezer bag big enough to hold the spool and a hygrometer, you can put them in and seal them up. Wait about 10 hours and read the humidity.
I don’t know your problem is water but I see my hygrometers peg at 10% with a well-dried spool.
Wow. Glad you checked. I recently changed out my AMS desiccant and redried the spools in them. I kept the spools in sealed poly boxes during the changeout/drying and was seeing numbers in the 32-33% RH range. That filament (PLA) was still printing mostly ok but was starting to have minor issues.
I hope you solve it. Maybe someone else has ideas?
I prefer to use something more heat resistant than PLA for desiccant containers. I can put the whole container in the oven for drying without emptying it first. I use PA, but PC and ASA would also work.
I’ve already done a cold pull and thoroughly checked both the extruder and nozzle. Everything appears to be in good condition—no debris or issues.
The filament (both PETG and PLA) flows smoothly out of the nozzle in a straight vertical line.
I’ll do another cold pull just to be sure, but what puzzles me is that the first layer seems to print just fine. If the nozzle were partially clogged, I would expect it to affect the first layer as well.
I had a similar issue a while back with my A1. In my case I had recently replaced my nozzle with a brand new one. About 10 hours of printing time later everything I tried to print (filament or model) worked for a bit and then just left my entire printer looking like a snowman had exploded on it - tiny bits of fluffy filament everywhere.
After hours of trying to figure out the problem I eventually got around to putting my old nozzle back on - and the problem was instantly solved. There is clearly a clog somewhere in my new nozzle that intermittently messes up the flow, but I cannot for the life of me find it or clear it out. It worked at the beginning, so I know the nozzle isn’t defective - it’s just clogged in some way that’s not easily cleared. If you have a spare nozzle it might be worth swapping it out to see what happens.
What happens if you print a different model? If other models print OK at least that will narrow your troubleshooting down and you can rule out things like a problem with the nozzle or extruder.
The new nozzle just arrived and now the X1C is printing properly again. I still don’t see any debris or clog in the old nozzle. But of course it must be there.
