Surface problem at 0,08 height

Bloodcyclon · January 31, 2024, 1:02pm

Hi!

I’m pretty new to the P1S and still getting used to the machine and the slicer.
I made some test prints with a new filament (Eryone Silk PLA Dual-Color, print temp 190-220°, bed temp 55-70, print speed 30-100 mm/s) and used the trusty benchy model.

First I ran a print with the profile of Bambu Labs PLA Basic, no changes whatsoever. 0,2 mm layer height and it came out great:

Next I wanted to print with 0,08 mm layer height and used the corresponding profile and the filament settings of Bambu Labs PLA Basic. And it came out like this:

Since then I calibrated the filament, I changed a lot of variables (layer height, speeds, extrusion temperature, ironing, number of walls, different infills, infill density, you name it) but I never got it good looking.

Even with 0,16 layer height do I get those strike artifacts and blisters. Only with 0,2mm layer height everything works fine.

I don’t get it and I’m stuck… Can someone point me in the right direction please? Thanks in advance!

Lexi · January 31, 2024, 1:56pm

If you want successful and pretty prints at smaller layer heights, you’ll likely need to use a smaller nozzle. It’s not impossible just more difficult.

Olias · January 31, 2024, 3:36pm

I’m actually a bit surprised you got results this good.

You’re using the incorrect profile. Silk filaments generally require higher temps. You could try the Bambu PLA Silk profile. However, it should be noted that all of the profiles are only approximations and the notations on the MFG carton cannot be trusted. You will want to master filament calibration. There are tons of posts here and also some great YouTube videos as well. Then calibrate your filament to your use-case. Temp and speed are just two of four major variables but if you take the time to go through the various YouTube tutorials, you’ll be rewarded with a greater understanding of how your rig and each filament will perform. Unfortunately, there is still way too much variation between filaments.

Another trick is to use the quiet mode which will print at 50% speed. The trade-off is quality over speed but it will give the filament the best possibility to flow smoothly if the profile isn’t perfectly calibrated.

Bloodcyclon · January 31, 2024, 7:49pm

Thanks for your answers!

@Lexi Nice read, thank you for the input!
But I printed on 0,08mm layer height before (with another PLA) and it printed just fine, so I thought that it should work with this PLA as well:

@Olias I calibrated the filament thoroughly. I don’t have all the tests around anymore, but I did them all (except for maximum volumetric speed, which shouldn’t be the problem here?).
This is the temp tower and as you can see, there is de facto no difference in between the temps:

And here the pressure advance calibration:

I think I got the calibration sorted out? Have I overlooked anything?

And regarding the speed: I printed a benchy with only 60mm/s print speed (something my 10 year old RigidBot can handle) and it had similar flaws as the others.

I also analyzed the model and the sliced model to check if I can see any correlation between the artifacts and the model/slicing, but I couldn’t recognise any.

Do you guys have some more ideas on how I can improve the quality or do you think this will hardly work, because of the 0,4mm nozzle?

Olias · January 31, 2024, 9:35pm

I don’t think you missed anything per se but there are some refinements in testing methodolgy that I have found may give you greater granularity in your calibration. No mind you, what I am going to suggest you may not see any difference, that is until you come up against a specific flow/shape geometry that is really tough for the filament/layer height combo.

All these are also in Orca.

The PA Pattern test is one I love. But it is not as precise as the tower test. But it runs in 5 minutes first 25 minutes for the tower test. 95% of the time, it’s good enough.

The max flowrate test is a punisher though. That leaves no room for discussion. Try that out too. But note that you won’t see a difference in a Benchy because max flow rate really only impacts those models that have longer continuous filament flows.

Temp Tower

The temp tower test is controversial. At first, I was in the camp where I saw no difference. That was until one YouTube video really showed how to critically look at it. Again, the eyeball has a tough time looking at the difference unless you know how to look at it.

In my experience, when using the temp tower is like a committee, There are five test parameters and depending on what your use-case is, you will likely be forced to chose one refinement such as stringiness over let’s say crispness of text. At first glance it all looks the same but check out these examples.

Here are some examples using 0.28 layer height.

The Black filament was Overture PLA which I specifically purchased because Bambu has a default setting for that PLA and I wanted to see how close it got. The box say 190-220. Bambu profiles says 220.

Bambu setting

My setting after calibration

Here’s why. I’m only showing the extreme closeups of the temp tower corners to exaggerate the spectrum, this tower was a test between 190 and 230. I later did one between 225-255 and settled on 240. Then I ran my PA Tower and max flow rate tests.

The 230 and 190 corner. Note how much sharper 230 is vs 190.

The 230 and back edge. I think 190 looks marginally better than 230 but that’s a judgement call

Compare the inside overhang for the 200 and 205. This might be important if your model has small overhangs otherwise the corner performance might influence your judgement more. No contest here 200 looks best.

The point here is that you have to take a critical look at each of the five parameters and determine which one is best suited for your use-case if at all. You may see what 90% of everyone else sees and that is, very little difference between temps.

Here’s another example using a single layer test. This one I came up with on my own and it is a pain in the @ss but it tells you a lot about retraction and max volume.
The one on the left is retraction of 0.70 and the one on the right is 0.931 which is what the Orca retraction test came up with. So you might mistakenly believe that 0.70 since it gave the smoothest run would be best. But it isn’t, the test is misleading. Upon printing a Benchy, I got voids because my retraction was too high. I only include this test here to illustrate how easily one can make a mistake by selecting only one parameter.

What to look at on a temp tower

These are the five points of inspection I feel they don’t fully explain in the tutorial. Many folks already know these but I’m willing to wager many more don’t. At least I didn’t at first, I had to piece this together from other YouTube videos and 3D printing blogs.

The first 3 can greatly be influenced by layer height and speed.

Corner sharpness vs layer adhesion
Overhang stringing
Rounded corners with sharp vertical slopes.(Smooth is better… sometimes)
Retraction stringing. Sometimes this is impossible to calibrate out but at least you get to see what temp will influence it. Influenced by retraction.
Letter crispness which indicates the ability to flow uniformly in crisp turns. Also influence by Max Flow rate.

One last trick I learned from Len Dizzle of “Filament Fridays”

Don’t rely on your eyesight, use a camera and blow it up on a screen

My personal tip. Use a lighted jewelers loop to really get a great look at details. This is even better than zooming in with a camera.

Here are my favs.

https://www.amazon.com/dp/B0BP6L3X6C/

https://www.amazon.com/dp/B08RRZ6CFN/

SimEyeSee · January 31, 2024, 10:13pm

Is there a reason you suggested the Bambu silk profile over the generic silk profile?

Olias · January 31, 2024, 10:18pm

Great question. I found that the generic profiles are way too conservative to the point of being almost detrimental. Max Flow rate was just one area as an example. So I’ve become very distrusting of those profiles. However, in this case, it would be worth a shot if the Bambu Profile doesn’t give an improvement.

Bloodcyclon · February 1, 2024, 8:21pm

@Olias Thanks for the idea with the jewelers lense. I guess I’ll buy one.

And thank you for the extensive explanation on what to look out on the temp tower! This will be saved in my personal knowledge base.

Today I have printed the bunny instead of the benchy. Printed on 0,08 mm layer height and 60mm/s speeds for walls and 105 mm/s speeds for all internals as well on another print i doubled these speeds to 120 mm/s and 210 mm/s respectively. Further increase of print speeds didn’t lower the printing time, so I guess I’d hit the max flowrate barrier there.

Both came out really nice:

And both had some flaws similar to the benchy in areas with greater overhang (also similar to the benchy):

Please remind me: Which variables influence the overhang performance? Where can I tweak that? Or is this a hardware limitation of using the 0,4 nozzle?

Olias · February 1, 2024, 10:52pm

There are too many parameters for overhangs to list. But here’s a shortcut to finding them.

Click on the magnifying glass next to the filament.

When the search pops up, type in “overhang” and it will present you with the 20 or so places in the slicer that has overhang settings. Then it’s business as usual, trial and error.

However, note that there are a number of tutorials out there which show you how to create odd positioning of models so that the draw of gravity will have the least impact on the model. Having said that though, there are times when you simply cannot get away without having some amount of stringing.

This one video in particular I found helpful in the application of using supports and model positioning an a creative way.

Now if I didn’t say it before, I’ll mention it now. Silk filament is a bitch. It is really hard in my view to get perfect results. I’ve only used Bambu Silk and one other brand and it required way too much calibration. Since I do mostly mechanical parts, I really didn’t have much of a need but anyone who master’s silk filament in my view is a 3D Printing Ninja.

Bloodcyclon · February 2, 2024, 4:30pm

Oh, that search function is nice! Didn’t know about that one! Thanks for pointing that out!

No, no one mentioned that before, but I can totally agree with that This is my first try on Silk PLA and I have to say, normal PLA is much simpler… But I’ll try becoming a ninja anyways

Thank you all for your time. I guess, I’ll do some trial and error for now.

user_4258596798 · March 24, 2025, 7:45am

Hi Bloodcyclon,
I have the exact same issue as per your first few images on this thread. I print the same product at 0.08 layer height and its worked great for the last year. Then i went to print this product this week and i got the same grainy patches on any area of the piece that has overhangs, even when they are really shallow.
Did you get to the bottom of this at all ?

user_4258596798 · March 24, 2025, 10:17am

Just incase anyone else has spent a week messing with overhang settings, flow rates etc, etc. For me this exact defect as shown on image 3 from the op, was fixed by simply changing the nozzle (i.e. new nozzle same type). Must of been worn or just dirty.
Hope this helps