Solid Top/Bottom Layers vs 100% infill
I recently tried to make a small print at 100% infill as an experiment. It ended up with globs on the surface which isn't too surprising (although I'm sure I could adjust the extrusion to make it better). I noticed that the first few layers looked OK, and it wasn't until the print switched from the "solid" bottom layers to the 100% infill layers that the globs started happening, which seemed odd since I thought they would be the same thing.
As another experiment, I made a simple 15x15x10 box, 0.2 layer height, 50 layers. I printed one with 2 top layers, 2 bottom layers, and 46 rectilinear 100% infill layers in between. Then I printed another one with 25 top layers and 25 bottom layers. The one with the 100% infill (right) looked much like my previous 100% infill part. But the one with 25 top and 25 bottom layers looks OK. Shouldn't they be the same? Is a "solid" top/bottom layer actually different than a 100% infill layer? I looked in the g-code and the extrusion width is the same, but since they are diagonal its hard to determine if the spacing/overlap is the same.
RE: Solid Top/Bottom Layers vs 100% infill
most infill types are barred from 100% infill, and those that allow 100% infill often fail as noted.
I always use top& bottom layers for preference
Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Solid Top/Bottom Layers vs 100% infill
Which filament are you using and are you sure it's dry?
https://www.matterhackers.com/news/filament-and-water
wbr,
Karl
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Solid Top/Bottom Layers vs 100% infill
Only rectilinear can do 100% infill. What I am trying to understand is why a 100% infill layer is different than a top/bottom layer. Shouldn't they be the same thing? They clearly are not.
RE: Solid Top/Bottom Layers vs 100% infill
Which filament are you using and are you sure it's dry?
https://www.matterhackers.com/news/filament-and-water
wbr,
Karl
Same filament and conditions, printed back to back. I've switched between them several times one right after the other. 100% infill does it, all top and bottom layers does not. It's the only thing different. I've even printed them next to each other at the same time, same result. Something is different.
RE: Solid Top/Bottom Layers vs 100% infill
Assuming you are using PrusaSlicer, after slicing look at the legend in the top left corner and see fan speeds and print speed/temperatures and other options.
My first guess is some horrid temperature creep (are you sure you are using proper temperatures to given filament, also sometimes filaments are mislabeled such as you think you have PETG but you have PLA)
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Solid Top/Bottom Layers vs 100% infill
I don't think you are understanding the problem. If I print at 100% infill I get a mess, If I print with all solid top/bottom layers it is fine. If it was wet filament or wrong temps and speeds, it would affect both. This is simply switching between 2 different methods of producing a solid cube and getting different results.
RE: Solid Top/Bottom Layers vs 100% infill
I've created such cube in PrusaSlicer 2.6.1 with 20 to/bottom layers for horizontal shells and the only thing that is noticeable is different Layer Time and Fan Speed for top/bottom layers, which increases print speed and fan speed.
Looking at the photo from your first post the cube on the right gets more bulges the higher from the plate it is as if it was just getting hotter.
> Then I printed another one with 25 top layers and 25 bottom layers.
What was the infill in that print? 100%?
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Solid Top/Bottom Layers vs 100% infill
> Then I printed another one with 25 top layers and 25 bottom layers.
What was the infill in that print? 100%?
It doesn't matter, there were no "Internal Infill" layers where I have control over the fill %. They were ALL ether top or bottom, "Top Solid Infill" or "Solid Infill".