Hello everyone!
I’m having issues while printing with ABS with my A1. All my tests are done with PLA or PETG as the first layer, after that I set Bambu Studio to change the filament to my green ABS. With PLA and PETG, all my tests below works perfect, and this is my first time ever printing with ABS. Also, this is my first 3D printer, so I’m not sure how to do some stuff yet.
So… I first printed a temperature tower test and I could see that my filament works best with 240ºC, with the least amount of stringing in the test. 8 - Tower_Temp_ABS_230-270ºC.3mf (1.6 MB)
You are doing well so far in terms of staring with basic filaments and trying the right approach to ABS settings worked out.
Not every noob does this
Your main issue here is time.
Try your stringing pillars again but clone them 2 or three times to print them by layer, not by object.
You will see a significant change for the surface quality as now these pillars have more time to cool down.
So check and play around with the cooling settings to see if you can further improve the cooling for fine details like the benchy top.
There is not just layer time to consider with ABS but also cooling time, like with the benchy.
ABS stays very soft for very long, which means for fine details you might need a much slower print speed and/or or add a little waste pillar on the plate at some distance to the model.
With slow travel times this again gives those fine details more time to cool.
The nozzle temp is quite relative with ABS when the print has high speed and very slow speed areas.
It keep oozing and the longer it stays in the melting chamber the more it oozes.
Try another temp test but use just a simple cube with no infill and no top layers.
Print with three walls and see whether or not you can pull the layers off with some pliers or such.
If not lower the nozzle temp by 3 to 5 degrees and try again.
Once the layer bond fail use that temp, add 5 degrees and use it as you baseline.
As for the retraction…
Try not to mess with both speed and distance.
Manually extrude about 5mm of filament, use something to quickly wipe over the nozzle then see for how long it keeps oozing…
Repeat but right after the wipe manually retract 2 or 3mm - check how long it takes now to start oozing again.
Use this to find the required retraction distance that gives you just enough time between print moves - don’t retract too much as this can get air inside the melting chamber…
The speed has to be determined by trial and error.
Start low and check when you start to see a cleaner ‘lift off’ with the z-hop enabled.
Note this value and keep going.
Once you see no further improvement determine a mid range value and give it a go.
Heheheh, thanks! I bought my A1 last BlackFriday, since then I’ve being using PLA and PETG. I just noticed this temperature and retraction test when I got a RED PLA that was ozzying a lot, making a lot of strings. So I learned about this.
So I did this, I cloned twice, and I spread the 3 objects as far as I could.
This is what I got:
The one in the back (still looks bad):
OMG, I have never used those manual control, LOL. I will try that tomorrow. I think I’ll need a video guide to instruct me in that. I will search on youtube.
And thank you very much for all this instruction!
To get more cooling on the chimney, increase fan speed for “Max fan speed threshold.”
That sets the fan speed for layers with shorter layer times … like when printing the chimney.
If you have “Slow printing down for better layer cooling” active, you can also slow down printing speed by increasing “Layer time” for “Max fan speed threshold.” This causes printing to slow down so that layers take at least that long to print.
The only issue is this minimal string in the last layer. Any advice on that?
So right now I have the temperature set to 240 and max cooling set to 100% with 7 seconds layer time.
The poles are so smooth to the touch, with no artifacts whatsover. When I tried to bump the retraction I started getting some small punctures in the pole, so I’m not sure what to adjust right now.
Only the top layer (last layer) that is showing just teeny-tiny string in the retraction test (poles)
----Edit
I could also get a very good result with 50% fan and 9s layer time. I’m trying to get a better result because the first benchy with 100% and 7s showed a crack near the back round window. Probably because it cooled down too fast and didn’t adhere so well. But at least now I’ve an idea of what is happening.
Especially with higher temp filaments there is a delicate balance between enough cooling to maintain details but not so much as to reduce layer adhesion.
For the top layer, you can try dropping the printing speed from 200 > 150 mm/s.
