Bottom Layer Fill Patterns
Searched around previous posts for a discussion of this but didn't find anything that directly addresses it. I frequently use the Hilbert Curve fill pattern for the top layer because of the pleasing texture it puts on the part. This begged the question: What would a bottom layer fill pattern of the Hilbert Curve (or any non-rectilinear pattern) look like? So I tried it. Apart from the first layer taking forever to print (it was a fairly large piece), there wasn't much to see because subsequent layers simply cover over the Hilbert pattern and the bottom surface of the part simply takes on the character of the bed, which in this case was the smooth PEI surface. So wouldn't this be the case for ANY pattern chosen, in which case, what's the point of allowing the bottom layer fill pattern parameter to be changed in the first place? Am I missing something subtle?
It’s there so that you can change it to your likings, but I would go for rectilinear as it is the easiest to print and gives the model strength as well as adhesion on the bed. Honestly, I have trouble with a curve on my first layer.
My point is that, for the bottom layer, it doesn't matter what pattern I choose, the finished print still looks the same, so why offer the option to change it?
I've used archimedian chords on a circular base and found with the textured base you end up with an 8 segmented pattern in the light as you move it around when printed with a glossy petg filament, looked great on the end of my air rifle moderator.
You still can see the individual extrusion lines at the bottom of the print with the smooth sheet. It is just less pronounced than the ones at the top, the setting is there so that you can change it. For example, I can clearly tell the difference between different infill patterns, it may be for more of an aesthetic reason. For mechanical parts I don’t see any reason to change it to anything but rectilinear. You can experiment with the different patterns, and see which one works for you. This is how it works, you experiment with settings and come up with ones that work best.