Bottom Layer Fill Patterns  

RE: Bottom Layer Fill Patterns

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.

RE: Bottom Layer Fill Patterns

@covertpluto

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?

RE: Bottom Layer Fill Patterns

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.

RE: Bottom Layer Fill Patterns

@reddawg

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.

RE: Bottom Layer Fill Patterns

you can improve adhesion and reduce warping

RE:

Posted by: @reddawg

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?

IMHO it depends on the filament. I've found that the FilamentPM Silver (like what came with my original MK3 from the days before Prusament) has a really neat effect when printed with Hilbert curve on the bottom:

That surface you see feels flat to the touch (printed on smooth PEI sticker sheet), but (especially with stereo vision) has an almost holographic appearance. Must be something about the formulation of that specific filament. My guess is it is a black PLA with ultra-fine silver "glitter".

I tend to use Hilbert curve on the first layer for two reasons. One is sometimes I get an effect similar to the above. Second (though I'm not sure if this is a real reason or not) I suspect that every time there is a right-angle in the pattern at least the inside of the curve is squished down into the printsheet a little more than on straight sections. My hope is that it creates a better bed adhesion than the default rectilinear.