Grid vs Gyroid  

RE: Grid vs Gyroid

I've been curious about this too.

My best guess is that the "cool" aspect about gyroid contributed to it being the default for the mini and MK3, but now with speed being the focus with input shaping being the big new feature, grid is preferred.

RE: Grid vs Gyroid

There are many factors that go into the selection of an infill. There are many webpages that discuss pros and cons, and a google search may well be worth it. 

Speed, as you measured, is one thing. Stability the infill provides to the model another one. And it may vary based on which directions forces get applied to the model. Other aspects include the ability to fill the object with other substances. 

From my personal experience.I found Gyroid to be an all-around good infill. I'm not a fan of Grid.  It's an infill pattern that has crossing lines within a layer which might lead to pile-ups at the intersection points, and in my experience, I've seen too many issues arising from that fact. For something similar I'd rather use Cubic  

In fact, Adaptive Cubic is an infill pattern that I routinely check for my models. For objects of merely ornamental use, I find myself using Lightning frequently. 

I've never seen much point in grid...

For a recent discussion on this topic see:

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-how-do-i-print-this-printing-help/settings-for-functional-strength/#post-659890

The link takes you to one of my posts but the whole thread is worth reading.

Cheerio

RE: Grid vs Gyroid

I have seen grid infill quality issues on MK4 as well when using IS. Gaps when crossing and the filament is pulled slightly up.  This results in the nozzle colliding into the filament at those points. Its pronounced enough that it is audible. The only way I could resolve it was to radically slow down the infill speeds ( non-IS settings ) and bump the temperature by 10C. I have a macroscope and took some pics as I adjusted the settings. I'll post them up if anyone is curious.  

Posted by: @jseyfert3

I'm a bit curious. Starting off with the MINI+, PrusaSlicer has gyroid pre-selected as the infill, so most of my parts were printed with this. And in their article on gyroid, they give it glowing praise:

The Gyroid is our favorite and one of the best infills. It’s one of the few 3D structures that provide great support in every direction. Plus it’s printed relatively fast, saves material, doesn’t cross itself at one layer and looks great. The special shape of this infill allows filling it with resin or another liquid.

Then I got an MK4, and they use grid as the default infill. So I took a part I've printed previously, and sliced it multiple times to compare. Relatively large part, lots of infill.

For all times, 15% infill, 0.2 mm layer height, 0.4 mm nozzle.

• Mini, quality: Gyroid 10:59, grid 8:55. Difference 2:04
• MK4, quality: Gyroid 10:29, grid 7:55. Difference 2:34
• MK4, IS, structural: Gyroid 7:42, grid 5:09. Difference 1:33

This part may be an extreme example, given the proportion of infill (80 g of 140 g print is internal infill). But my question is, why did Prusa decide that for the Mini the default infill should be gyroid, and for the MK4 it should be grid? Was it just so that the printer was faster by default? I mean it's already faster, regardless of infill type, but was the change in defaults just to make it seem even more faster?

Also, I note that for the MINI (and a quick look appears to indicate the MK3 too), the 0.2 mm Quality uses the 15% gyroid infill, while the 0.2 mm Speed uses 20% grid. Why does the speed profile for these use higher % of infill by default? Bumping up to 20% over the 15% in quality removes most of the speed benefit of the grid over the gyroid.

Oh, I just realized when I've printed parts in grid on my Mini, the grid often seems to have defects after the nozzle crosses the crossed gridlines. Like often it won't touch, there will be a gap. And I don't recall seeing that on my MK4 printing in grid. So maybe they put the default on the Mini to gyroid because grid has issues due to the reverse bowden extruder?

Am I just overthinking all this? 😆 

RE: Grid vs Gyroid

I havent use this gallery image approach so I hope it works right...

• MK4 5.0.0. alpha 4
• All were with temps of 250C 1st an 260C remaining
• Prusa Orange T
• Dried for 10 hours at 149F

RE: Grid vs Gyroid

Lets try this way :

MK4IS - PETG grid infill - 0.20mm SPEED ( default )

[img] [/img]

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MK4IS - PETG grid infill - 0.20mm STRUCT ( default )

[img] [/img]

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MK4IS -  PETG grid infill - 0.20mm STRUCT ( default ) + Liftz

[img] [/img]

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MK4IS - PETG grid infill - 0.20mm STRUCT  ( default ) + non-is infill speeds

[img] [/img]

RE: Grid vs Gyroid

I have noted a similar things on my FLSUN V400 where I am still fine tuning the profiles. When I print at high speed with PETG I should set gyroid as infill, because often the linear infills do mess, either at intersections of lines or also in the aligned lines. On the contrary the gyroid do a complex material deposit shape that even if not perfect deposited has still a structural strength compared to the linear that drops down.

RE: Grid vs Gyroid

Prusa's own description of Grid infill seems to imply it is fast.  That's probably why they chose it for the default profiles.  I don't like it for reasons they ALSO mention:

"This is one of the simplest and fastest variants of infill. Unlike rectilinear, it’s printed in both directions (rotated by 90°) in each layer. This way, material accumulates in spots where the paths cross. The grid infill is more solid (and has better layer adhesion) than the rectilinear infill, however, it sometimes can cause annoying noise or even a print failure due to the nozzle going over the crossings where material accumulates."

https://help.prusa3d.com/article/infill-patterns_177130

I tend to stick with gyroid or lightning infill.

RE: Grid vs Gyroid

So it seems that most prefer gyroid, or at least can't provide a super compelling reason for the change to grid. In another thread, I was wondering about the switch to 0.32 layer heights instead of the old 0.30 default. ( https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-general-discussion-announcements-and-releases/why-0-32mm-layer-height-in-the-new-profiles-whats-wrong-with-0-3mm/)

It would be nice if Prusa would explain their reasoning. Surely these aren't purely arbitrary changes?

RE: Grid vs Gyroid

So it seems that most prefer gyroid, or at least can't provide a super compelling reason for the change to grid. In another thread, I was wondering about the switch to 0.32 layer heights instead of the old 0.30 default. ( https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-general-discussion-announcements-and-releases/why-0-32mm-layer-height-in-the-new-profiles-whats-wrong-with-0-3mm/)

It would be nice if Prusa would explain their reasoning. Surely these aren't purely arbitrary changes?

RE: Grid vs Gyroid

I'm a sort of dissident in this matter, preferring rectilinear over giroid or grid.  Giroid is fine but my suspect is that the undulating pattern where the X/Y steppers are continuously changing the sense of rotation, will be more stressful for the steppers and belts. Maybe I'm wrong but, just in case, I stick to rectilinear infill for most of my projects .. and it's faster than giroid.

RE: Grid vs Gyroid

Thanks all. I think I’ll probably stick with cubic for things that need infill and strength, but I want fast speed. May use gyroid depending on application.

I’ve also started to use no infill, or lightning infill, if the part doesn’t need infill for strength.

RE: Grid vs Gyroid

I print with gyroid infill 90% of the time, that is all the time unless I need another infill for a specific reason