Surface finish issues with Bambu Lab Silk Filament

HotFix · October 6, 2024, 5:59pm

I have 3 different rolls of Bambu Lab Silk. Pink, Blue, and dual Orange/Red. With all 3 filaments I have noticed a top and side surface finish issue I can’t figure out or explain, that I don’t have with any other brand of silk filament (Flashforge, Eryone, GIANTARM, MIKA3D, etc…).

FYI - I print all silks @ 50mm/s for both outer walls and top surface, where prints already default to 50mm/s for the bottom layer, and never higher than 0.16mm layer height. What I am going to try and explain here is not an issue with the visible layer being too fast or too tall, and I print all silks at 230c.

Instead of trying to explain what is going on, let me show you. First up is a Tron light cycle I tried to print out of the Bambu Lab blue silk:

The print is using the exact same settings across all 4 bike chassis except for the other 3 are using the Generic PLA Silk profile with non-Bambu Lab silk filament.

I also noticed that just the Bambu Lab silk filament stuck REALY hard to the prismatic plates I was using, compared to every other filament. It was so bad that it left residue I had to scrub, not wipe, off, and I’m not the only one to report this.

This leads me to believe Bambu Lab has done something to the filament to try and make it print better.

The issues are very pronounced on the top layer as evident by these Unicorns I printed with Bambu Lab pink silk @ 0.16mm layer height (the top surface shouldn’t be rough like that at all), a giant fidget spinner that looks really bad on the top layer (I tried printed it with both the default top surface pattern and also concentric, both were equally bad with the concentric top surface being what is pictured), and then a top of a pumpkin print (printed at 0.12mm layer height) with the orange/red dual silk that got rough in a few random spots:

Then there are the issues with overhangs and surface quality as well. Not sure if it is in focus enough but hopefully the bottom of the pink tail on the unicorn is inexplicably rough. You can also see the bottom overhang is rough (I flipped it up for the picture) and some weird ringing on a wheel for the Tron bike:

I’m at a loss as to why all 3 Bambu Lab silk filaments have these issues consistently with top surface finish, side and overhang (even slight like in the Tron wheel), and generally sticking way harder than they need to every build plate. I’m also not the only one to have this issue as it happened to Frankly Built on his most recent video where he printed 4 Dr. Doom masks, all out of Bambu Lab Silk silver, and you can see on at least 2 of them that the filament is causing the same texture/surface quality issues:
Which BAMBU LAB 3D Printer is BEST…For YOU!

Again, no other silk filaments act like this, even close to this so I have pretty much sworn off Bambu Lab silk filament which is a shame since I love all their other filament.

Olias · October 6, 2024, 7:14pm

I get it, this is frustrating. Unfortunately, if you search the forum, you’ll find tons of posts about issues with Bambu Silk and Bambu Matte filaments. I’ve tried several variants of both, and here’s what I’ve concluded:

The factory filament profiles are just flat-out wrong. You’re better off doing manual calibrations.
Both Silk and Matte PLA need drying, and even then, they leave a sticky residue on the print plate that’s a pain to clean. On top of that, they produce consistently unsatisfactory results.

In conclusion, and your photos back this up, Bambu Silk and Matte filaments are garbage compared to other options. My experience has been the same. Here’s an example of Bambu Silk Gold straight out of the bag—terrible. Even after manual calibration, the improvement was minimal and not worth the hassle.

Check these two side-by-side photos: one from right out of the bag and one several months later after I used a filament dryer. You be the judge. Also, even after drying I had to hand-tune the factory defaults. This spool was from 2023 when Bambu was on their best behavior. Now it looks like their Silk and Matte filament quality control has only diminished.

Unfortunately, I had to make room in my slicer, so I no longer have that filament profile to upload.

Unless you’re locked into the AMS system and need Bambu spools, it’s clear that Bambu Silk and Matte are inferior products. To make it worse, recent posts suggest they’ve only declined since switching manufacturers. Add in the 40-60% price premium over competing filament suppliers, lousy return policies, and poor shipping options, and it’s a joke. Why pay extra for a subpar experience? It’s mind-boggling.

I would make a challenge to Bambu, give the same no-questions-asked, free-return, money-back guarantee on filament purchases that Amazon does and see how well the product does in that marketplace. Or better yet, put the filament onto Amazon and let them handle the logistics. "Competition is good".

___________________________________________________________

OK Rant over now on to making a positive contribution.

Here’s what I would suggest in this order.

Try calibrating manually. I recommend Orca Slicer with its baked-in calibration suite. Click on this video for a good primer.
Dry the filament. But before you do, make sure you weigh it before and after to ensure that you know you’ve removed the moisture. If you don’t have a purpose build dryer, the X1 has a drier mode using the build plate but it ties up your printer for a few hours. If you have a P1, see this DIY video which shows you how to dry using just any print bed and the filament box it came in.

image884×487 27.6 KB
Run the print and then run a calibration to do a side by side bake-off of your resutls
Post your results here so the community can benefit from your experience, good or bad.

HotFix · October 6, 2024, 8:33pm

I did search on the forums before I posted and only found a couple of references to Bambu Lab silk and surface finish issues. I don’t have anything negative to say about their matte filament at this time.

I do remember I tried drying the blue silk at one point with a good filament drying during the 1/2 a roll I wasted trying to get a good Tron cycle print. It made 0 difference.

I shouldn’t have to calibrate the filament with the X1C and dynamic flow calibration, right? I have used that for every one of the filaments I struggle with.

I even used the acceleration speed modifications (in addition to all the other modifications I referenced) listed on Printing with silk filaments and I still go the surface finish issues with the pumpkin top.

I think there is something else going on here, specifically Bambu Lab may have modified the makeup of their silk filament so it prints faster (volumetric flow of 12mm/s versus 7.5mm/s), but in so doing introduced surface finish isuses and cause massive adhesion to build plates.

Olias · October 6, 2024, 8:52pm

But the important question here is; did you weigh it before and after drying? All too often folks dry a filament without measuring the weight which will confirm or deny moisture presence. Also, if a filament has moisture, one can’t know that it has been completely dried until it stops losing weight.

From your lips to God’s ears. If only the products we all buy behave like the brochures says. The point is, manual calibration is the one method where you can observe and understand every aspect of filament performance whereas automated techniques work well… until they don’t…

That’s a good idea. Have you also tried testing “silent” mode which reduces all printer movements by 50% across the board?

This was the point I’m trying to underscore here. When it comes to the two classes of filament I mentioned, their product is not performing as well as the competition.

If I understand you correctly, your quote above, that I include below, hits the nail on the head. You’ve gathered the best kind of evidence—your own empirical data. There’s nothing better than that.

I might be paraphrasing Ockham’s Razor, but when all the obvious possibilities are ruled out, the least obvious answer is often the one right in front of you. You’ve proven that you can achieve high-quality results with competitor products. So, unless you’re specifically using Bambu spools for the AMS, why continue paying 60% more for an inferior product when you have beautiful results from other products?

HotFix · October 7, 2024, 2:14am

No in this case I did not stop to weigh the specific blue silk spool before and after I dried it. I have only done that a few times through the countless spools I have dried, mostly for my on curiosity because every time I have used one of my filament dryers have proven to me they work. I.E. I’m not running a YouTube channel and need to perform a product demonstration ; I just need to dry the filament which the dyers I have do.

I am not talking about, nor have I had any issues with, Bambu Lab’s Matte filament so respectfully I would like to keep this post focused on the Silk filament issue as I think the issues I and a few others have seen are unique to the silk filament.

No, I haven’t tried slowing the printer down even more with silent mode. My initial thought was because I could accomplish the same thing by slowing down the various print speeds in the slicer, but I don’t see how is going to make the top surface set to 50mm/s print any less rough.

I’m curious if anyone others out there have had experiences with Bambu Lab’s silk filament, and/or if anyone figured out a trick not covered by you or I.

I’m also curious if anyone from Bambu Lab reads these forums and responds to reports like this. The fact that 1+ million subscriber (Frankly Built) ran into the same issue using their filament and appeared to be equally stumped by it sure seems like Bambu Lab should engage and provide solutions or acknowledge the filament has an issue.