No Consistency on Surface Sheen Matte Shine Glossy Outer Walls Banding

Hi Guys

I need an expert’s help - I’m trying to dial in the settings on this simple 4 wall enclosure to just get a consistent sheen on the outer wall - I am using BLACK PLA Overture filament. I have tried various cooling, speed settings - and even created a temp tower in Orca slicer where I adjusted the settings accordingly. I am printing at 220 and slowed my outer wall to 25m - and this has worked - instead of a matte finish I am getting a slightly glossed sheen which is what I want - BUT as you can see in the pic - where there is a through hole - the sheen is different and there is banding. AND this time it is not even around the entire model - it is only on one side. How does this happen? In the slicer I have used the color scheme map and all key colors are consistent for Flow, Speed, Fan Speed and layer time banding is not evident. I will note that the enclosure door was slightly left open as instructed from another post I saw to avoid heat creep. (I closed the door as I am typing this as it is still printing - I am curious if the ambient temp change by the door opening has anything to do with this. If anyone has solved this issue can you please provide the settings you used? Thanks

You’ve already made a thread about this, why make another?

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Because the suggestions provided didn’t help and I wanted some new visibility on this issue.

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What you have going there is “Infill Projection”. This happens when the outer walls are not thick enough, and the infill starts showing through.
As the filament is deposited and then cools, it shrinks a little, this causes the areas of the outer walls to shrink around the infill pattern, causing the outer walls to warp slightly.
A few things can greatly help if you need a perfect outer wall.

  1. Increase the wall count on the outer layers.
    For parts that need to have appearance grade walls, I jump to 5 walls.
  2. Increase the infill percentage.
    A higher infill percentage helps mitigate the shrinkage that occurs as it shortens the distance between the infill lines.
  3. Speed up your outer wall.
    My outer walls speed is set to 200 mm/s (factory default). The reason this helps is slower speeds allow the filament too much time to cool and sag as it’s laid down across the infill.

All of these work in tandem with each other, and changing one will affect the others. I would recommend switching back to a standard profile, adjusting your temp settings and volumetric flow rate, then adjust the outer wall layers to 5 and see what you get.
Black is a difficult color to get perfect, as it shows any and all defects in appearance, so you will need to play with the settings a bit to get a surface you are satisfied with. Don’t be afraid to bump your temps up another 10 or 15 degrees either. PLA can handle those higher temps without any issue. I print eSUN at temps of 230/235 all day long with no problems at all. I also keep my lid on, and my door closed, without any issues of heat creep. PLA is a lot more robust than people give it credit for.

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WOW thank you for the thorough and well thought out answer - I will try this and update - at the moment I am recalibrating as I am now dealing with this:

All of a sudden my nozzle started grinding on the infill (not grid pattern but rectilinear) - it never did that before. If you have any ideas why this could occur I would love to hear it.

It looked to me in the video that the infill was nowhere near flat. I have seen a couple of times where the nozzle wipe that happens just before printing starts seems to bump the z height a tenth or two (not always, but occassionally) and gets the Z off a few steps.
Either that, or the homing sequence was off due to lead screw binding and it didn’t get the Z set correctly.
This can lead to layer adhesion issues and cause a print fail with exactly those symptoms. The infill gets bumpy and “muddy” scrapes the nozzle, and causes runaway problems as the nozzle continues to deposit filament.

There really is nothing to do except to cancel the print, and restart it. Make sure you have the auto leveling enabled, make sure the plate is located on the bed properly, and if you haven’t done a manual flow calibration, enable the flow calibration. That should reset things and get you back to normal.
Once the auto calibration is done, if you turn it off, it will continue to use the stored auto values until you recalibrate, so it isn’t truly necessary to run it every print.

Hello AIAmantea - here is the test print with the settings:


As you can see the print is Matte - there isn’t any banding - but this is pretty much what I was getting when I first started using this printer with the default settings - my goal is to get a nice glossy outside like I get with my Prusa MK3 printers.

So I was told to slow down outer wall speed - but did not do that here

I am going to try the same print but this time slow down the outer wall.

If there is anything else you see let me know - I was also told to reduce my cooling as well - I had it at 25% - but that is when the banding started to occur with different sheens but the through holes and hence this thread.

Bumpy our temps up another 5 degrees and cut your cooling in half.

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OK I believe this is acceptable! Thanks for your help @AlAmantea - I think the final and last setting were the increased wall loops. I am printing the larger print now and will report back.

As you can see there is still a slight inconsistency near the center through-hole but nothing that goes all the way around like previously and this one really depends on the lighting angle.

So I will mark these settings here:

Overture Black PLA Filament (Amazon special)
.20 Standard X1C Profile
.40 nozzle

Filament


Cooling

Quality - Default
Strength
Walls
Wall loops 5
Sparse infill density 40%
Spare infill pattern Aligned Rectilinear (probably does not matter)
Speed
Outer wall 25
Slow down for overhangs checked
0
25
Outer wall 2500

That is certainly a vast improvement over what you started with! Happy it worked out for you! Happy to help

Unfortunately I’m sad to report on the larger model there’s still banding near the through-hole on one side of the model - basically it’s not working like we hoped - and it’s such an odd problem it’s something to do either with the overhang or the bridge near the through-hole I don’t know what it is it’s driving me crazy

So my last experiment is removing the through-holes and marking small hole indicators on the inside of the model and therefore if the outer wall come out with a consistent sheen then I will just manually drill the holes. Not sure what else to do at this point.

I am happy to report that I got a consistent outer wall sheen without any banding - BUT I removed the through-holes AND I changed the speed of the inner gap infill to match the speed of the outer and inner walls. - I set them all to 100,

So my next experiment is to put the through holes back with these settings - perhaps it was the speeds of the inner gap fill causing the banding?

Very nice. Glad you started this thread and got help. Now others can use this thread. when I want the highest quality, i run at creality/prusa speeds. The high speed printing is really good if you dont care about quality and strength/layer adhesion. Sometimes i run fast with a single wall just as a test and then slow it way down for the final print.

Overnight I printed the complete model with the new settings I used for the previous tested solid piece - and though now I was able to achieve sheen consistency around the through-holes (unlike before) - now I have a bottom half that is more matte than the top. I am using the same, speed, temps, flow throughout.- the color scheme map shows all the same.

Below you can see the sheen change starts on the layer just where the first through-hole starts.

THIS TIME I AM CHECKING the layer color scheme map with the through-hole BUT enabled the TRAVEL indicator - and I see instead of the head moving around around and around in a circular pattern - the head moves back and forth in half circles; Each time stopping at the hole and then reversing

1 side and then stops at the hole and then reverses and goes back around to the other side of the hole

This has to be the reason.

So the trick is to get the tool head to continuously flow filament around in a complete circlet each time.

Perhaps if I add supports in these areas.

Amazing - how much investigative work and filament waste in order to get a consistent look.

I will report back

In that case, I wonder if a seam gap adjustment would help.

I am sure support will not help. The object printing is same: around to the hole and reverse. Mmmhhh … difficult … I think you have to find a temperature and speed setting where the filament doesn’t change its behaviour.
Did you try another filament brand and/or color?

I would imagine it has everything to do with the print head accel/decell rates when the head reverses at the hole.
I don’t believe there is any way to force the tool head to continue straight through and print in one direction (Similar to the way monotonic infill is in relation to rectilinear infill) but I would be willing to wager that this would solve the issue.
About the only thing I can see to verify any changes would be to look at the speeds in the preview window and see if things are consistent. Another thing could be to change the print order of perimeter walls and infill to see if that makes any difference in sheen.

The only real workaround I can come up with for you would be to print the part at 100% infill and then drill it out after printing. You could use a part modifier to change the infill percentage in only the areas need so you aren’t doing the entire part at 100% infill.

Can you all believe that support finally responded - I sent them this exact post, logs, files, etc and guess what? They said NOPE can’t be done. Though, I can do this perfectly fine on my PRUSA MK3, just takes a lot longer. They told me (as I already tested prior) - don’t use through-holes and print a solid object and drill them yourself. (So I just risk damaging / scratching my print in the process then and potentially making my print unusable.) So the answer is - have a MATTE finish and sacrifice the gloss sheen or don’t use through holes if using black filament. You can’t have both!