Uneven laying - filament related?

[MooseJuice]

Hello…

Having issues with printing again.

The first layer is always kinda wavey, which seems to ripple throughout the entire print.

This is very noticable on larger, flat items… I’m getting very tired of screwing with this. Truth be told, smaller parts that dont have large flat areas don’t seem to come out bad… It just seems like big flat parts. The little waviness may be present on the first layer but usually it levels out after a layer or two.

Now, I have tried hot… I have tried cold… I have tried fast… I have tried slow.

I have done extruder calibration, I have done linear actuation…

I print temperature towers, which all look the same on the posts, and none of the bridges look good, minus the hottest one which is usually kind of thing but at least stays where it belongs.

Long story short, I am really getting frusterated. Every time i make a step forward something else gets worse.

So right now, I had attributed the problems to crappy filmament, from a supposidly good brand, but measuring it, its quite oval.

However, this spool I have now, which was purchased from Snapmaker (after they rejected the orginal material, this should be the esun material now), is also out of round.

Both brands, i can measure 1.75, i can measure 1.73, i can measure 2.25. Depends on where I spin it.

If the diameter of the filament is the source of my issues, where do I find filament that isn’t straight up garbage… I have so many brands… so many colors…

I try lowering the flow rate, I try slowing it down…

I also tried the retraction test, the posts looks identical all the way up.

Here are some pictures of what is coming out of my printer, trying any number of settings:

You’ll see I tried doing the same part many times, i start the job and walk away, go to work and come back or whatever… now im more able to look at it and kill it much faster.

Note the top of the calibration cube, Z dimension is off while X and Y are closer to each other and the target.

The wrinkling on the print bed, the poor extrusion on the top surface… but… the sides are coming out so much nicer with the linear setting of .06 based on the test.

I can also put one of the many versions of the G-code for that part, this is the most recent:

I want to post the gcode for the file right now but it wont let me because its too large it says… so all I can share is the start of it where the values are defined

;Generated with Cura_SteamEngine 4.7.1
M82 ;absolute extrusion mode
;M104=print temp, M140 = bed temp, 109 = print temp wait, 190 = bed temp wait
M104 S210 ;Start heating extruder
M140 S50 ;Start heating bed
G28 ;home
G90 ;absolute positioning
G1 X-10 Y-10 F3000
G1 Z0 F1800
M190 S50 ;Wait for Bed Temperature ;Wait for bed to reach temp before proceeding
M109 S210 ;Wait for Hotend Temperature ;Wait for extruder to reach temp before proceeding
G92 E0 ;Reset the extruder’s origin/length
G1 E1 F200 ;extrude 1mm @ 200mm/s feedrate (prime)
G92 E0 ;Reset the extruder’s origin/length
G92 E0 ;Reset the extruder’s origin/length
M900 K0.06 ;Linear Advance K-Factor
G92 E0 ;Reset the extruder’s origin/length
G1 F3600 E-5

I’ve done the bed temp, nozzle temp, flow rate, etc. Top layer quantity was 7

[brent113]

I feel for you @MooseJuice, 2 steps forward, 2 steps back.

Well the easiest thing to start with is the filament. Using an online ellipse area calculator the cross sectional areas of an ellipse that’s 1.74/2.10mm diameter is 2.87mm², but a 1.75mm circle is 2.40mm². That would lead to overextrusion of 19.6%! That’s super bad, but can be adjusted for if it’s consistent through its length.

If you unspool 20ft or so and check the minimum and maximum diameters, is it consistent? If not, you’ll get waves of over/under extrusion.

I’ve had good luck with Hatchbox, I haven’t used Prusament but understand it’s manufactured to a tight tolerance, and I’ve seen other recommendations around from @sdj544 and @atom that I can’t recall this moment.

Just focusing on this area:

Knowing the toolpath will come back and fill in that small area later, it looks like the filament got thicker and is overextruded compared to the surrounding area.

[Atom]

So the line in the red circle looks like a travel path. If your oozing some filament while the tool head moves it tends to leave lines like that.
The green circle is somewhere that didn’t finish printing on that layer yet.
The waves in the orange circle appear to be over extrusion or warp.

The last one is the hardest to fix, my questions are this 1. Is this a structural part (do you need really good cohesion)?
2. What is your line width set at?
3. Are you seeing any first layer adhesion issues in that area?

[MooseJuice]

For brent,

regarding the filament consistency, i cant find a 1 meter span similar let alone 20 feet. However, its generally within .02 from one area to the next. I think… I have about 10 different spools of material and I guess I will open them all now to see if ANY of them are not shit.

Unfortunately my hatchbox is PETG which I am thinking maybe I should just stay away from for awhile to avoid destroying things with my fists.

So if my oval is consistent, i could calculate how much over it is against the 1.75 and the extruder should be able to accommodate with adjusting the flow rate despite it not being round is what you are saying? Sounds like you had a formula or web page for figuring that out?

On to atom,

Green circle - that was a finished part in that particular case, it just finished like that… I can see why you would say that, but you can tell the 3 round bosses extending up beyond that layer.

Some of the pictures are not finished parts, but if they have those bosses on them, they were finished.

Line width has been .4 but also tried a bit smaller .32

Yeah, I do have first layer adhesion issues there. I think, not the entire area, but some of it. It kinda depends, it looks like maybe anywhere I have more than a calibration cube (which seem to always come out really nicely) it begins to do that.

It is not a structural part, no. It is, however, decorative. Its part of a mechanical light switch cover I wanted to put in my office and just looks like garbage.

I gave up on that, and am now trying ABS for awhile…I got it to stick with some magigoo, and printed some test cubes, but there are separations - going to turn up the heat some more on my next go.

Decided to try to make a functional model for something some asked me for at work, a clip to attach to their welding helmet so they can open it without touching the glass. Playing with 3d modeling beyond extruding a 2d shape is really exciting concept to me…

I will be switching back to the PLA to try this model again, this was a good distraction for me. The ABS is not easy to get to stick but at least I accomplished SOMETHING positive yesterday (a prototype of the part, which split into 5 separate hunks from adhesion issues, but at least its something that looks good and finished printing…) I have a revised model and I am going to keep printing it til it comes out how I want, its only a half hour print job at 100% infill so it will be a good exercise.

[brent113]

I just googled ellipse area calc and used the first one, seemed to work well enough. Make sure and use the radius and not the diameter like I did hahaha: https://keisan.casio.com/exec/system/1223289167

You could take the area from the calculator above and solve for the circle diameter that’s equivalent to that (if A=pi*r^2, then diameter would be 2*(A/pi)^.5) and plug that into the filament diameter in the slicer.

You could also instead find the ratio by dividing the areas to figure out how much of a factor you’d need to adjust your extrusion multiplier by. With my previous numbers of 1.196x as much being extruded, you’d just divide your extrusion multiplier by that.

[Atom]

If that is a finished layer that is very odd… seems like a slicer error to me. I say that because of the way that all of those style lines follow the radio’s of some other part. Its like the slicer meant to go back and fill them in, but then didn’t.

Having the width just a bit smaller(like you said you tried) can make up for some of those waves when you have a large flat piece.

I have had a lot of issues with getting good adhesion across the A350s bed, and we all know that @brent113 bed is far from flat.

I will admit that I never have gotten a good smooth finish from the SM2 like I do with my ender3 and I have yet to figure out why.

[MooseJuice]

Well, I guess hopefully we can figure it out together over time!

I am back on that part, this time with ABS

I am trying a concentric pattern on the top layers this time

[MooseJuice]

So I am experimenting a lot to try to resolve this… Alot of it is over extrusion as predicted, but what I don’t understand is

if I print a raft, it looks gorgeous. Why would the top of my print look different than the top of a raft?

I am going to be looking very closely at the raft settings to try to transfer them over to my top layers.

Also, perhaps my understanding of top layers is not correct,

I have 3 bosses on this print that stick up about 3/16 of an inch.

Is it possible that the “top layers” are literally only the top layers of the bosses instead of the top layers of all surfaces?

If that’s the case, perhaps if I figured out how many layers were in the bosses, and added 6 to that… it would work?

[Atom]

That depends on the slicer your using. I know cura applys the “top & bottom” setting to the first and last x layers for any given spot. Not sure why your raft would come out better. If you have a separate top layer flow setting you can try adjusting that?

[brent113]

In addition to what atom said - rafts printing fine but not top surfaces tells me there’s a difference between unconstrained regions (raft) and constrained (top).

With a raft you spiral outwards.

With a top surface a perimeter is set, and then infilled.

With unconstrained regions small amounts of overextrusion will be impossible to visually see unless you’re measuring with a micrometer.

With constrained regions any overextrusion will be forced upwards.

Tops are very sensitive to

• Number of solid layers over the infill
• Infill density
• Infill overlap percentage

The first solid layer over sparse infill will be horrendously underextruded as the filament is continuously bridging and will take on a circular cross section and have virtually no horizontal pressure adhering the filament together. This results in a layer with small depressions between adjacent extrusions and not a smooth surface.

The second solid layer will be placed down on top of the underextruded first solid layer and has the job of trying to get the surface more smooth, but it is still filling in the previous underextruded layer, and as such will also be slightly underextruded.

The third layer may or may not be correctly extruded. Some people will see underextrusion on the top layer at this point and reprint with a high extrusion (flow) multiplier. This is not necessarily the correct fix, however. The rest of the print will not be overextruded.

The number of solid top layers needed to get a smooth surface will change with the layer height, with thinner layer heights laying down less material and therefore requiring additional solid layers to get a satisfactory result. There are rules of thumb, like you should have at least 0.5mm of solid layers, so at a 0.16mm layer height you would want at least 4 layers. I think that’s a bare minimum and increasing does not hurt.

Endlessly tweaking the extrusion multiplier, as some people are wont to do, will have different effects on different models depending on the size and location of features. One way to permanently fix, if this is the only issue, is to increase the number of solid top layers, or increase the infill density. There are other ways, as well.

What I think you should do is double check a calibration cube printed in vase mode with a single extrusion width and verify it matches what the slicer says the extrusion width should be, to within a tolerance of +/-0.03mm or so.

Then, when you print a calibration cube with a solid top with 3 solid layers and also 6 solid layers, do they look the same?

• If the 6 layer test looks correctly extruded and the 3 layer is underextruded than you may need to increase solid layer count.
• If the 6 layer test is overextruded but the 3 layer is correctly extruded, that’s not good and needs to be treated as any other overextrusion would be, because the overextrusion on the 3 layer just happens to be balancing out the underextrusion-like effect of the first couple solid layers being printed over sparse infill - this is not a stable setting and will be sensitive to different shapes and sizes of features.
• If there are small pinholes as the infill pattern changes directions that may be infill overlap percentage related, or linear advance K factor related.

Once a flat calibration cube looks good, try the other types of cubes with other features of different sizes. The surface quality should not change between a large flat area and small flat area - if it does something in the slicer is still set wrong.

I know you’ve done lots of this already, so pick and choose things that sound helpful.

Once the machine is fully and correctly set both in firmware and in the slicer you should be able to print (within reason) at any layer height, any speed, and any model and it will come out the same. Getting to that point, however, goes faster with experience and can take awhile.

[MooseJuice]

Thanks, that is a lot to digest

I will briefly add before digging into your suggestions that I have done this with both a 15% infill and 100% infill. The sparce infill creates pillowing, which as you described does gradually become nicer with more layers

I think that just the way the layers are printed out in general being different is a significant portion of my problem.

It would be nice if I could tell cura just to print straight lines, skipping over the holes, as opposed to doing one section, then finding another area that mathematically in time makes the most sense to print, as the coming and going of the prints per area seems to be the major culprit of this coming out so poorly.

I’ve also found that removing the “top skin layers” seems to make a positive impact, although you wouldn’t think it should.

[brent113]

@MooseJuice

It would be nice if I could tell cura just to print straight lines, skipping over the holes, as opposed to doing one section, then finding another area that mathematically in time makes the most sense to print, as the coming and going of the prints per area seems to be the major culprit of this coming out so poorly.

What you’re describing, in part, is why Simplify3D costs $150. They have spent a lot of effort optimizing that.

[MooseJuice]

Well if Simplify3d is capable of helping here, I’ll buy it right now.

[brent113]

Cura is a capable slicer, and switching to S3D will not make under/over extrusion problems disappear. I find its path optimization and standard supports slightly better than Cura, although Cura has it beat on bridging and tree supports.

Also I think they have a “trial”, you can “return” it up to two weeks.

I particularly like S3D’s thin extrusion features (variable extrusion width and dynamic gap fill) - it’s a real problem solver in areas that need some fill but don’t have enough space for a full .48mm extrusion width - it does the math and carefully under extrudes to fill in the volume correctly. I’ve had great luck with it.

[MooseJuice]

Can you explain what vase mode is? I saw that mentioned on a file recently too, but I don’t see anything called that in luban or cura?

[brent113]

Vase Mode Settings for Snapmaker Luban

Hello, In Luban you’ll have to make a custom profile by doing this: [image] Then you’re looking for Spiralize, here: [image]

[MooseJuice]

Oh okay the spiralize thing, I tried that once, made a very thin but well detailed shell, i stopped it partway thru

[brent113]

What to do with it is detailed here:

Teaching Tech 3D Printer Calibration