First layer infill differs from second layer when using no bottom solid layers

[Cyondil]

What happened?

I have created honeycomb patterns in blank spaces before in various items and have done this successfully in the past. I am now using version 2.5.59.8 and have noticed there seems to be a problem when using infill with no bottom solid layers. The first layer seems to be offset/a different scale than the subsequent layers. This seems to happen no matter the pattern type for the infill.

First Layer in 2.5.59.8

Second layer and after in 2.5.59.8 (not the same):

Since I have done this successfully in the past, I decided to download an earlier version, 2.5.59.2 and it worked correctly. Seems a bug was introduced in a later version of the program. See below for examples:

First Layer in 2.5.59.2:

Second layer and after in 2.5.59.2 (same):

Project file & How to reproduce

350_Front_A_2.5.59.zip

I take the original file and then make it separate objects to apply individual settings to the "insert" pieces. To the individual insert pieces, I apply no bottom or top solid layers and then apply the infill settings (20% infill and honeycomb).

I included the project files from both 2.5.59.8 and 2.59.5.2

Version

2.5.59.8

Operating system

Windows 11

Printer model

Voron 2.4 with Stealthburner

[devsfan1830]

Just want to report that I too have this exact problem as I too do this to add a mesh on my Voron skirts. Had to make a new one to fix some keystone fitment, and suddenly this occurs rather than having the infill neatly stack. This issue did not occur for me either on earlier versions. I am also on 2.5.59.8. I have attached my project file in case that helps. keystone skirt (2).zip I can also confirm I had to roll back all the way to version 2.5.59.2 in order to correct it.

[julianjc84]

The issue is your Extrusions Widths. Printer Settings: Width & Flow: Default Printer Settings: Width & Flow: First Layer Printer Settings: Width & Flow: Infill

Set the Default and First Layer as this impacts how infill is calculated and generated. As well has Infill width plays a big role too, this will likely fix your issue.

also Perimeters & Shell : Quality Only 1 Perimeter: On Top Surface will impact the Top layer infill.

[devsfan1830]

The issue is your Extrusions Widths. Printer Settings: Width & Flow: Default Printer Settings: Width & Flow: First Layer Printer Settings: Width & Flow: Infill

Set the Default and First Layer as this impacts how infill is calculated and generated. As well has Infill width plays a big role too, this will likely fix your issue.

also Perimeters & Shell : Quality Only 1 Perimeter: On Top Surface will impact the Top layer infill.

Yep, looks like setting widths identical fixes it. I am able to leave the only 1 perimeter on top surface enabled. Interesting that the older version didn't require this. Was that a bug that was fixed?

[Cyondil]

I guess the question I have now, is this the "intended" way things are or is this something that got introduced (possibly a bug that finally got fixed?) since 2.5.59.2. As @devsfan1830 mentioned, I have been able to have this work without needing to change any settings previously and was using the same settings I have always used. If so, easy enough to change it when I need to do prints like this, but would be nice to know if this is the way things will be moving forward.

[supermerill]

duplicate of #4131 #4145

[Cyondil]

Thanks. Since this is marked as a duplicate, I will close this now.