Defects in slopes/outer perimeters. What is it called and what causes it?
Just finished the assembly a few days ago and it's all about testing printing now. Everything seems mostly OK although honestly I had no idea what I was doing with the first layer Z calibration. How are you supposed to see the shape? Anyway, after initial PLA prints I started working on this transparent blue ABS-T filament. Some prints have turned out great but there seems to one defect that I haven't figured out at all yet. I haven't been able to track down the exact conditions when the defect occurs either. It seems to appear in slopes (bottom side).
See how it only occurs in the beginning in the slopes (the right side in the picture is the bottom while printing). The difference between the two is just the other one has different shell thickness parameters. The exact same defect seemed to occur. The one on the right has been sanded a little.
I interrupted this print when I saw the outer perimeter edges started looking all wonky.
The picture below is a closeup of the raft and the brim. Dunno if it's relevant or of any use in the diagnosis.
What is this defect or problem called and what is the likely cause of it?
The filament package says 1.75 mm ABS-T 230 - 250 °C. I'm using 240 °C and 100 °C temperatures.
Re: Defects in slopes/outer perimeters. What is it called and what causes it?
sagging from heat.... try more walls/shells and add infill? i see no infill. idea to so soak up the heat. also try min layer time/cooling to slow down the print to give it time to solidify before the next layer goes on top. you could try the cooling fan but it might just warp the print off the bed and weaken layer adhesion. last case is add supports for it to lay on... though technically with PETG/PLA you wouldn't it's just a worse if any of the above don't work.
Re: Defects in slopes/outer perimeters. What is it called and what causes it?
Thanks for the reply. Interesting! I guess it does in fact look like issues with heat. The bottle opener prints had very different shell and infill parameters but the defect seemed to be exactly the same regardless. The other pictures are of the Earbud holder design. All walls are quite thin so there's not much I can do about infill or shells. There were also multiple parts layed out on the surface so as far as I know there should've been plenty of time to cool down between layers.
I tried one more print with 230 °C, very slow speed and only brim—no raft. Pictures below:
To me it looks mostly great but again the slope undersides have the problem.
It might be just a coincidence or because of something else but it seemed like everything was much worse with the raft. Could that possibly make any sense?
How much can the issues be attributed to the filament material alone? I just sort of happened to get an ABS roll as well and wanted to try it. Should I just ditch it and stick to other materials like PLA and PETG?