A few days ago I got my first 3D printer (Bambulab P1S Combo). I started with some test prints. The included Bambulab PLA worked fine, then I tested eSun PLA+, first I had some stringing (I hope that is the correct word) but then it worked fine as well.
But then i tried printing with SUNLU PLA + 2.0 and I do not understand why the prints look so ugly. My test print is a Zelda Rupee.
This one was with the included Bambulab PLA, seems pretty good, printed with default settings
Bambulab PLA
This one is with eSUN PLA +, not perfect but ok.
eSUN PLA +
And the yellow on is the one that always turns out ugly. I tried to tweak some values, calibrated the fillament in the settings.
SUNLU PLA + 2.0
After some reading is decided to print a temperature tower.
Those where the settings in the slicer
What are those deformations called?
What is causing this?
I really hope someone can explain my mistake and help me get this working. Thanks!
The temp tower pic’s give a good indication as to the root cause. It looks like basic overhang drooping with a dash of curling.
To make that geometry, a line needs to be deposited with minimal contact to the underlying material, i.e. mainly in the air. To look good, it needs to be cooled extremely rapidly. While it is cooling, the material, subject to gravity and sitting mainly on air, droops.
Related to that is curling which can also occur if the the line is fully supported and bonding well with the underlying material. As it cools, it shrinks. This in turn pulls the local line upwards. It is particularly vexing in high speed prints where it can even lead to nozzle bending. Special cases relate to first layer curling (also important for that case: bed adhesion) and warping.
There are a couple of things that can be done to improve this.
First of all, moist filament tends to stay warm longer, leading to more serious drooping, curling and warping (see curling but at a global level). So drying filament can help quite a bit. And keep in mind that filament fresh out of the bag is not neccessarily dry. By the time you print it, it has already travelled the seven seas…
Next, it may be tempting to play around with cooling. However, in my experience, that is akin to opening Pandora’s box. It is much easier to “slow down for overhangs” (enabled as a default) and/or just slow down further.
Also, from your temp tower example, orientation can matter. Was the bad side facing the Aux-fan, the front, left door corner or closer to the poop chute than the good side? Overly rapid cooling or locally different environmental temps can play havoc with cool down behavior. Edit: If printed as in the screenshot above, the frayed edges on the right show insufficient cooling since that side is shielded from the Aux-fan.
Furthermore, curling and warping can be addressed to some extend by reducing the heat input (so as to soften less of the underlying layer and reducing the pull forces occuring during cool down). Similar to slowing down, its effect is volumetric and hence quite helpful. In particular “adaptive layer height” works a treat.
Finally, there are physical limitations. At least until the long awaited “Siemens Lufthaken” is finally released. High angle overhangs need supports for acceptable surface quality.
But that is Pandora’s second box…
For now, I would suggest to just dry the troublesome filament. At least you will then know with certainty how far you can push each filament in terms of overhang angle.
When cooling is a problem, should I try to print with open printer door?
I will try to dry the filament. I opened another package in a different color and the result is mainly the same. It is a bit overwhelming with so many variables
I think that in this particular case it is much more important to dry the troublesome filament. If after that it is still troublesome, try slowing down overhangs further to give more time for cooling from the part fan.
As for open or closed, printing open reduces the chamber temp and hence increases the likelyhood of warping and curling.
The reason why an open door and lid is recommended is another type of print failure: Heat creep. The warmer the chamber, the more likely will heat creep occur leading to a clogged nozzle.
On my X1, I can easily read the chamber temp. With PLA, I always target 35-39°C BUT only without surface ironing! When using ironing or having a print with many large retracts, print open.
On this print: 1) Dry the filament
2) Print with adaptive layer height but the other way round (Quality between 0 and 0.5): You need finer layers on the overhangs to counteract curling. Thicker layers will make the print worse.
You can also adapt the local layer height by right/left clicking in the colored side bar for fine tuning.
You may also want to check if “slow down for overhang” actually comes into effect in the slicers speed preview. That’ll help if you need to tune speed settings. Also, you seem to have a large temp window. So changing speed will have more of an observable and controllable effect than trying to solve temp and cooling. Never mind several factors all at the same time…
But make sure the filament is dry. There’s not much point in playing with settings on a filament which may have significant moisture in it.
If we loosely compare it to cooking: No amount of tweaking will turn rumen into veal!
The hygrometer in the bag does not neccessarily tell us much about the filament itself as the filament will not give up the moisture it already captured without being forced to by heat.
Also 42% is pretty high. In my AMS, I use the cheap round hygrometers. They can only display down to 10%. Once they read 11%, I know that the dessiccant is longer able to keep humidity down and give it a (careful) ride in the microwave.
My bet is that the main problem is short layer time because the part is quite small, so each layer doesn’t have enough time to cool before zhe next line is layed on top.
Short layer time is a common issue with very thin structures. It is easily addressed by printing two (or more) identical objects at the same time or forcing a prime tower.
However, since the textured plates impression is shown on the “top”, we know that this does not apply here.
You still have the benchy bow issue on the side opposite the seam. Usually it shows issues with from a missing pressure advance calibration or, and from the defect I assume that this is the case here, early curling.
I’d suggest placing the seam here (by painting it) or checking if it is due to the orientation on the build plate by rotating the part by 45°.
Also, I noticed that you are focusing on the good filament atm. It may also benefit from some drying.
