What size nozzle are you using? A 0.4mm nozzle can't really get away with a layer height of 0.1mm and a 0.2mm nozzle can't get away with a line width of 0.38mm.
And by "filling in the top corners" you mean this?
(Things are always so much easier to show when you have colour scheme set to "line type")
At your line width, there just isn't room to get a narrower gap in:
11 hours ago, Slashee_the_Cow said:What size nozzle are you using? A 0.4mm nozzle can't really get away with a layer height of 0.1mm and a 0.2mm nozzle can't get away with a line width of 0.38mm.
I'm using a 0.4. I was led to believe that a layer height of 0.08 was possible, so I thought I was being conservative. What is the smallest layer height you would recommend? I can switch to a 0.2 nozzle of it's not small enough.
11 hours ago, Slashee_the_Cow said:And by "filling in the top corners" you mean this?
Yes.
32 minutes ago, Adventurehill1 said:I'm using a 0.4. I was led to believe that a layer height of 0.08 was possible, so I thought I was being conservative. What is the smallest layer height you would recommend? I can switch to a 0.2 nozzle of it's not small enough.
There isn't a particular guideline for minimum layer height for a nozzle (just that your maximum should be about 80%). It's largely a matter of how good your printer is - the thinner your layers get on the same size nozzle, the more accurate your extrusion has to be. Especially to control flow for different parts of a model, you will eventually run into a hard limit based on the size of the E step. If you have a Bowden extruder, then forget about really thin entirely - on a 0.4mm nozzle I wouldn't even try anything shorter than 0.12mm. Even on my printer with a direct drive extruder, results start to get a bit iffy if I try anything below 0.1mm on a 0.4mm nozzle, but I don't exactly have an expensive printer (Ender-3 V3 SE).
I'm just curious about your priorities here - you're trying to print 0.1mm layers with 0.4mm lines - that just doesn't compute to me (but most things humans think don't, so it must be a cow thing).
Generally the idea with thin layers is to print fine detail, but for fine detail you're much better off reducing your line width (guideline: about 60-150% of your nozzle width) first. And if you're not going for fine detail, then why go for such short layers? It'll just take longer to print and be more liable to get messed up in the process (as you've seen).
With a 0.2mm nozzle you should be alright to do 0.08mm layers, but you'll want to reduce your line width to 0.3mm, maximum. But if you go with 0.3mm (or anything above 0.24mm, going by the guidelines) lines then you're defeating the usual purpose of a thinner nozzle, which is higher detail, so you'll get something pretty similar to what you could do on a 0.4mm nozzle anyway, but take more time doing it.
17 hours ago, Adventurehill1 said:Also, the settings on this profile produce some pretty disastrous results...
yes. No idea what is going on there.
I have seen .06 layer height with .4mm nozzle and it looked pretty damn good. But not every printer can do that - the Z axis in particular will likely move .07mm one one layer and then .05 on the next and this creates a lot of ugliness. In my opinion .2mm layer looks the best but on a really well made printer with super clean and well greased Z screws and with a highly accurate extruder, 0.06mm can look better than 0.1.
I would try thicker layers (start with 0.2) and every other setting the same to see if the issue is indeed layer height. Instead the issue could be print speed - no idea. Or crappy printer - no idea what causes that weird mess on your "calibration cube".
2 hours ago, Slashee_the_Cow said:I'm just curious about your priorities here - you're trying to print 0.1mm layers with 0.4mm lines - that just doesn't compute to me (but most things humans think don't, so it must be a cow thing).
I need a smoother surface on my print than a 0.2 height and 0.42 line width will give me. It's an aerodynamic part, and it needs to look good as well.
1 hour ago, gr5 said:yes. No idea what is going on there.
I have seen .06 layer height with .4mm nozzle and it looked pretty damn good. But not every printer can do that - the Z axis in particular will likely move .07mm one one layer and then .05 on the next and this creates a lot of ugliness. In my opinion .2mm layer looks the best but on a really well made printer with super clean and well greased Z screws and with a highly accurate extruder, 0.06mm can look better than 0.1.
I would try thicker layers (start with 0.2) and every other setting the same to see if the issue is indeed layer height. Instead the issue could be print speed - no idea. Or crappy printer - no idea what causes that weird mess on your "calibration cube".
I've been trying to debug this sloppy mess my printer call finished prints for a while now. So far for PETG I've tried changing temperature, print speed, retraction settings, and cooling, as well as some other minor changes. It all looks about the same.
I'm no expert, but I think the Z axis on my machine (Anycubic Kobra Max) is pretty decent, it has dual z motors and everything.
I don't really want to change layer height more than I have to, since I need a smooth surface, but I can switch to a 0.2 mm nozzle.
18 hours ago, Adventurehill1 said:I need a smoother surface on my print than a 0.2 height and 0.42 line width will give me. It's an aerodynamic part, and it needs to look good as well.
Try using 0.12mm layers and a 0.24mm line width - you should be able to pull that off with a 0.4mm nozzle.
18 hours ago, Adventurehill1 said:I don't really want to change layer height more than I have to, since I need a smooth surface, but I can switch to a 0.2 mm nozzle.
To get the best results with that, regardless of layer height, you're going to need to do some manual post-processing... and by that I mean sanding.
Remember that it's a circular nozzle so lines aren't going to come out square. Each line is a little tube, basically, so the edges are round:
What I don't know about aerodynamics could fill a wind tunnel but without smoothing off the surface manually, shorter layers = smaller gaps but more of them, taller layers = bigger gaps but less of them. But if you minimise your line width then the edge of each tube won't protrude as far out from the centre, which is probably the more important part.
On 4/1/2024 at 3:41 PM, Adventurehill1 said:Also, the settings on this profile produce some pretty disastrous results...
Unfortunately the new layer height and line width settings still make a model that looks like it was 3d printed by hand. I am wondering if it is my nozzle, so I will change it for the next print.
1 minute ago, Adventurehill1 said:Unfortunately the new layer height and line width settings still make a model that looks like it was 3d printed by hand. I am wondering if it is my nozzle, so I will change it for the next print.
I have seen some pretty impressive works done by the the "3D Pens" you can buy. I have a cheap one because it's good if a model needs a touch up (or you can use it to join models).
A partially clogged nozzle could definitely mess things up. It's also possible the hot end might be partially clogged, but try changing the nozzle first because it's a much easier thing to fix 🙂
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Here is the result with a brand new nozzle. The strange stuff on the outside of the print can be removed by hand without leaving too much scarring, but I would still like to know what's happening.
This picture is so much more helpful!!
So it seems to be printing reasonably well once the support has stopped. So for now you should only be worrying about the portion where there is support involved. I can see that this side is severely underextruded - probably <50% extrusion.
Is it the same on the back side?
It seems like your settings probably change between the support and the print. I didn't look at your project file but I would make all the settings the same although it's almost certainly either line width or print speed.
When you are printing at a certain volume per second, the pressure in the nozzle takes a little while to equalize. This is particularly a problem for bowden printers but all printers. If you, for example, speed up, the pressure is too low in the nozzle and it takes a few seconds to equalize - during that time you get underextrusion. Then overextrusion when you slow down for a few seconds until the pressure in the nozzle lowers enough to equalize again.
Similar with changing layer height or line width.
Also retraction amount, if too big, can get air in the nozzle.
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1 hour ago, gr5 said:I didn't look at your project file
The main discrepancies when it comes to flow:
So we got a couple of changes there. I'm not sure why you'd need to increase infill flow, especially since it already has a higher flow to begin with:
No idea why you'd want to have the infill slightly wider than everything else.
Since as @gr5 said the results seem to be alright after the support, I'd set support flow down to 100%. Some people actually turn it down a bit so it's weaker and easier to remove from the model, but we're probably looking at a flow problem here, so we want to make the flow consistent. And speaking of consistent, change the infill line width to the same as the line width and set its flow to 100% so on every layer it's not constantly changing back and forth (in your picture it actually looks like it gets worse at it gets near the top, which definitely could be a "flow having to change back and forth" thing).
Temperatures:
The project says you're using PETG - I've never seen PETG printed that cool before. I run mine at a nice 245°. If it's not hot enough, that will cause adhesion issues (as well as possibly flow issues because it'll be a bit gluggy when it's heated).
A "personal preference" sort of thing, but I run the fan at 100% for PETG since it's not very sensitive to temperature changes.
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Hi @Adventurehill1,
You've got plenty of good advice's here.
As I've found this issue very strange, I did a little research on your print profiles and Cura.
Slicer and firmware here:
https://store.anycubic.com/pages/firmware-software
I've found out that "redit" made the two profiles present in your printer, TPU and PLA.
I'll guess that you modified the TPU profile with the temperature for PETG, yes we do this for sure.
However, all your acceleration and speed settings (plus more) are made for TPU.
A better chose would be to use PLA parameters and just modify the temperature settings.
Thanks
Torgeir
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3 minutes ago, Torgeir said:I'll guess that you modified the TPU profile with the temperature for PETG, yes we do this for sure.
However, all your acceleration and speed settings (plus more) are made for TPU.
A better chose would be to use PLA parameters and just modify the temperature settings.
I respectfully beg to differ. My PETG profile (40mm/s) is a little faster than my TPU profile (30mm/s) but slower than PLA (60mm/s).
For detailed things like this (not that I often do them in PETG) I actually run my acceleration at 500mm/s², less than my normal prints with TPU, but 650mm/s² is still a reasonably controlled acceleration.
My PETG profile is much closer to my TPU profile than my PLA profile. For example, PETG (1.5mm) requires a longer retraction than PLA (0.8mm) because it can get very stringy, but not quite as high as my TPU profile (2mm). And yes, I'm using a direct drive extruder so the numbers won't be the same for you (but the relative difference is the point, not the absolute difference).
You also need to cut down on retractions a bit if you can compared to PLA (but again, not as much as TPU) because it's a softer filament so doesn't stand going back and forth through the extruder gears nearly as well as PLA.
Overhangs, I'll admit, are close to PLA: PLA comes out the nozzle reasonably solid (comparatively) so can handle overhangs better. PETG comes out a bit stringy, but still reasonably in shape. TPU comes out soft, so tends to handle overhangs worse (though sometimes I amaze myself about what I can pull off).
1
Good analysis, Slashee. That 110% flow is definitely a potential cause of the problem.
speed
Again, I haven't looked at the profile, but what about speed? cura profiles tend to do different speeds for each type of "line". e.g. infill, support, outerwall often all have different speeds but I don't like that - it lends itself to brief over and underextrusion. The engineering profiles all have constant speeds.
temperature
CPE and PETG are pretty similar (same thing?) so if there is not PETG profile I'd start with CPE and modify temp. CPE and CPE+ are Ultimaker-only brand filaments I think. I print a lot of PETG. I use 230C. I just checked.
fan
I've never touched fan on CPE/PETG which is at 20% which is STUPID as my UM3 and my S5 both are at 100% when you set them to 20%. So I've been fine with "100%" fan but the next time I reslice one of my PETG prints I will lower that to 2% (if printed on UM3 or 4% if printed on S5). I would try 20% since it sounds like you don't have an Ultimaker printer and that's what is in the CPE profile.
Fan probably has nothing to do with your underextrusion (it's possible - sometimes air bounces off build plate and cools nozzle especially on lower layers). If you have trouble with adhesion, lowering fan can help especially with higher temp materials. If you have ugly overhangs you want more fan. PLA usually needs more fan than 90% of printers out there are capable of delivering so with PLA always go 100%.
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14 hours ago, gr5 said:I can see that this side is severely underextruded - probably <50% extrusion.
It's not underextrusion. (Sorry for not explaining better) It's more like a flaky surface layer that can be peeled off (Maybe overextrusion?)
12 hours ago, Slashee_the_Cow said:
I'm not sure why you'd need to increase infill flow, especially since it already has a higher flow to begin with:
No idea why you'd want to have the infill slightly wider than everything else.
The project says you're using PETG - I've never seen PETG printed that cool before. I run mine at a nice 245°. If it's not hot enough, that will cause adhesion issues (as well as possibly flow issues because it'll be a bit gluggy when it's heated).
My infill has been having issues with just "bunching up" at the intersections, so I have everything set higher to help it stick where the extruder puts it.
Also, I believe my hotend runs hotter than displayed by a good bit, which seems to be a Kobra problem. I've printed everything between 220 and 250 and for me 225 is the sweet spot.
11 hours ago, gr5 said:if there is not PETG profile I'd start with CPE and modify temp.
There is a stock profile for the Kobra, but it's pretty bad. I added it to the reply so you can take a look.
Hi @Slashee_the_Cow and @Adventurehill1.
Ofc., all discussions around problems like this are valuable -and I'll sure agree with your suggestions.
However, there are some differences in here we'll need to take into consideration.
Printing with a (1.5 mm or 0.8 mm) diameter nozzle versus a size of 0.4 mm makes some differences.
If we compare the 0.8 mm and 0.4 mm nozzle we'll see it is 0.8 mm is twice the diameter of a 0.4.
Further, -the surface area of a 0.8 mm is four (4!) times bigger in area.
In addition this printer use a bowden tube, but I do not know the retraction length this printer are using. I'll know that some "Ender 3" types with bowden tube use the same retraction length as my UM2E+ (6.5 mm), "assuming" this Anycubic printer are close to this length.
Printing with a 0.4 mm nozzle need much higher feed pressure in order to work properly here, so using a higher speed and acceleration are really needed to improve this problem IMHO.
For the Anycubic printer reduce the speed from 80 mm/s (PLA default) "maybe" reduce the speed to say 60 mm/s and keep the acceleration the same as default PLA.
When I started printing with PETG I've used PLA and modified the parameters according the specs for the brand of PETG.
Only adjusted the speed from 60 mm/s down to about 45 mm/s, else only the temp and the fan (no fan until 25 % of print done then fan on at speed 20 % to the end). Used bed at only 45 deg. C., but with printer closed in front with a top hat as well.
Well, -inside the web site of Anycubic they recommend using PLA profile as a "template" for PETG, but need to reduce the printing speed some.
As you have the Anycubic profile for PLA, why not try this type of filament to have a little confidence with your printer.
Most of us in here started printing with PLA.
Just my 5p
Thanks
Torgeir
This print looks much better and I've seen that the acceleration and the speed are more like "PLA".
I've just magnified your test cube for a more detailed look.
This print looks much better.
Try to reduce speed from 80 mm/s to 50 mm/s.
Reduce the retraction length from 8 mm to 6.5mm.
The surface looks very disturbed, is this a brand new filament just removed from a sealed bag?
Also we'll see acceleration/resonance marks in here, so reducing speed may help.
Almost all types of thermoplastic attract water directly from the moisture in the air, so it is very important to keep it in a sealed bag with dehumidifier bags (after printing) to prevent this from happening.
But again "PLA", doing calibration without proper tuned filament profile are very challenging.
PLA are easy to get and cheap..
Anyway good luck.
Thanks
Torgeir
Unlike PLA, PETG absorbs water from the air and if you don't keep it dry it will "string" a lot. What happens is the water boils and foams the filament slightly which causes it to expand.
If you have a heated bed, the easiest way to dry PETG is to unspool the amount you will need, place that on the bed with the spool on top (no need to cut the filament as it's still attached to the spool). Cover with a blanket or towel and leave at 50C for at least 2 hours. 2 hours is enough to get the unspooled portion. 8 hours will get some of the spooled as well.
After printing with the dried filament, put in a sealed zip lock (I use 2 gallon) and include a cup (1/4 liter) of color changing desiccant. Recharge the desiccant when the color changes (typically once every few months).
Your "flaky surface layer" might be related to overextruding which might be related to "wet" filament.
I've never had this "flaky surface layer" with petg - just thick stringing. For me "stringing" is the only symptom I get when I have wet PETG. Other than that the quality is okay. When I dry the filament, the stringing goes away.
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I'm too lazy to use @gr5's desiccant method so I just bought a filament dryer from Amazon, not expensive (about AU$75) and just stick my filament in there and run it for a couple of hours before I print and it's good.
15 hours ago, Slashee_the_Cow said:I'm too lazy to use @gr5's desiccant method so I just bought a filament dryer from Amazon, not expensive (about AU$75) and just stick my filament in there and run it for a couple of hours before I print and it's good.
I have a filament dryer, which I used then printed again. The results are, well, exactly like before.
the last two cubes have been printed with the settings I attached. I'm really not sure what else it could be. I will print again with line width and flow same for infill and support and see what happens.
Well, -It's the support that's destroy your model in the first place.
Rotate your model so the "Z" is pointing straight up, the turn off the support -then you will have a much better model to analyse, for the one trying to help you and for yourself.
Are you sure you're using a 0.4 mm size nozzle? Or, could it be a much to high feed rate setting in your firmware?
I'll ask this as the line width setting in this last model was 0.24 mm (for a 0.4 mm nozzle) Cura warn you here with "Min layer width 0.34 mm). Still your model looks like this.(?)
You're using Cura 5.6.0 , Anycubic advice using Cura 5.2.0 as the profiles are made with this version, I would jump to Cura 5.7.0!
Maybe you tell us a little bit more about your printer.
Thanks
Try printing this. I tweaked a few of the settings for (hopefully) better results.
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Also, the settings on this profile produce some pretty disastrous results...
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