Hey guys,
My printer recently starting giving some artifacts on the exterior surfaces. Calibration didnt help fix these “errors” so Im curious if anyone can recommend what might be causing this?
How are you drying your filament?
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Its a new roll of Bambu PLA, shouldnt need drying straight out of the package.
Filament should not be considered “dry” in the packaging.
The defect you are seeing is normally caused by moisture in the filament expanding in the hotend which creates additional pressure that “spurts” out.
Look familiar?
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I’m not sure why you would believe a new roll of filament wouldn’t need drying, in most cases they do, even PLA. See here for your specific issue:
https://wiki.bambulab.com/en/filament-acc/filament/dry-filament
Edit: Jon was faster than I
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Agree with drying, unless you happen to have Seam set to Random and didnt tell us 
So I dried the suspect filament for 12 hours but issue persists, and also noticed the same surface problem on some new blue PLA.
Question, can too high of an ironing flow cause these similar issues? Just noticed my ironing is set to 20% while I believe default is 10%. Not sure how/when that changed but I think I’m moving it back to see if I notice improvement.
Running some ironing calibration tests to see if the issue can be improved on the dried filament.
I checked the settings on Bambu and found my son did change seam to Random when printing a “Squirtle?” figure. Changed that back to “back” and the defects are gone. I also saved off a settings preset that says “BEN DO NOT MESS WITH THIS” so hopefully this doesn’t happen again 
Not sure why Random seams does this, but obviously @Bullocks does since he mentioned it.
Wet filament just didn’t make sense as I’ve been printing fine for years with the same brand of filament, same conditions, etc. and never had an issue with wet filament before. I’d buy that a single roll could have started to cause issues but multiple? Nope, doesn’t make sense; although to put you all at ease I have dried every open roll of PLA for 12 hours.
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To be fair, it really does resemble a wet filament condition. Now that you know it’s the seam setting, it looks to me like you may have further settings issues, random seams alone should not cause large bumps like the ones shown in the picture, and is likely caused by a combination of things and/or settings.
If you’re happy with how things are, great. If you do want to go down the rabbit hole to figure out the actual issue with your random seams, here’s a starting point: Advice for reducing random seam bits? - @Olias has a good write up and a couple video links, this may or may not be slightly out of date.
In any case, my prints that are round with random seams do not print with those giant blobs, but I do have my PA, flow ratios, and retractions dialed in, which took me a lot more time than I’d like to admit.
Random seam is a great way to make gears and spinny bits mesh better. A big “ridge line” from an aligned seam catches every rotation, in a way that 100 little speckles doesnt. For aesthetics I think it ruins them.
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One of the issues is that the X1 has printed near perfectly for so long, I’ve probably got a little lax on the proper maintenance and calibration. It’s a testament to how good of a product Bambu puts out, but every now and then you have to take a step back and remember it’s just a machine that needs maintenance like anything else.
That is what I’m doing this weekend. Cleaning happened last night and general maintenance & calibration is going on today. I’ve made minor adjustments to flow rates and PA value… now walking through some ironing calibration prints to adjust as needed.
Calibration prints are already coming out better so it’s definitely on the right track. I’ve got a couple X, Y, Z calibration cubes sitting next to me that look perfect aside from some final tweaks to ironing.
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