Perimeters print time depends on infill?
To explain what confuses me, it's the easiest you if start PrusaSlicer, add a Box shape, set Top layers to zero and slice (other settings are not really relevant in this case -I used PETG, 0.20mm QUALITY, 2 perimeters, 15% infill, for PrusaMINI.
Legend on top left corner shows time used: 5min for Perimeter and 7min for External perimeter. If I now only change Infill to zero and slice again, then I get: 7min for Perimeter and 8min for External perimeter.
Ok, in above case difference is relative small. But I also tried with some other objects (bigger, and a bit more complex), and the same happens (with increased time differences).
My question: why print time for perimeters increases if I reduce infill?
Best Answer by Neophyl:
See you say no project is needed but even in this simple case it is. I did what you said and added a box, (25mm) and selected my normal profiles. Ok I normally have 3 perimeters so I left that. I then set the top and bottom to zero and infill to 10%. I got a 27m print time with 19 minutes worth of perimeters, 9m external and 10 minutes internal. I then set infill to 0% and sliced. I then got a 20m print, same time for the perimeters (9 and 10) and the minute was for the skirt so that didnt change. This was with PS 2.3.3 so I'm not seeing the same change you are.
I'd guess that its your cooling settings from your filament profile. The slow down print time in layer is below xx setting. With no infill the layer time will be shorter and depending on the setting this could trigger that threshold. Once again my filament profiles are customised for my printer and I have that value set to 5-6 seconds so its not likely cutting in on me. All guesswork though without a project file.
[Mini+] [MK3S+BEAR]
RE: Perimeters print time depends on infill?
See you say no project is needed but even in this simple case it is. I did what you said and added a box, (25mm) and selected my normal profiles. Ok I normally have 3 perimeters so I left that. I then set the top and bottom to zero and infill to 10%. I got a 27m print time with 19 minutes worth of perimeters, 9m external and 10 minutes internal. I then set infill to 0% and sliced. I then got a 20m print, same time for the perimeters (9 and 10) and the minute was for the skirt so that didnt change. This was with PS 2.3.3 so I'm not seeing the same change you are.
I'd guess that its your cooling settings from your filament profile. The slow down print time in layer is below xx setting. With no infill the layer time will be shorter and depending on the setting this could trigger that threshold. Once again my filament profiles are customised for my printer and I have that value set to 5-6 seconds so its not likely cutting in on me. All guesswork though without a project file.
RE: Perimeters print time depends on infill?
And you're absolutely right! -I'm impressed to say the least.
Yes, at default settings, Filament>Cooling "Slow down.." is set to 15 seconds, which triggers on smallish parts, of course. I must admit I never really paid attention to Filament Cooling section.
Thank you very much.. I guess I owe you a beer 🍺 .
[Mini+] [MK3S+BEAR]
Another reason to include a project is that, you are asking a question that you apparently don't know the answer too, and this is most likely because something you are unaware of is effecting your project, we could play 50 questions, and keep guessing or someone who does know can look at your project in five minutes time and tell you what the reason is. This can also work the other way around, the responder in some cases could make an example that can demonstrate the the effect of something or the way to do something.
For example, if we saw that you had auto cooling selected in your example we might suspect that because of the decreased layer times (with the removal of infill the layer was slowed down to allow it to cool properly. but not all of us have auto cooling on, or setup the same in our profiles, etc, etc. however auto cooling would effect different shapes and sizes in different ways. if we have your .3mf file we can see your specific problem the way your using slicer.
BTW I'm not trying to solve your question here, I'm chiming in on Neophyl's comment.
See you say no project is needed but even in this simple case it is.
It's the most effective way we have to help, and communicate an issue or Idea relative to our prints, I'll go one farther, it's also very helpful in diagnosing filament related issues.
Regards
Swiss_Cheese
The Filament Whisperer