Elephant Foot Compensation Conflicts with Initial Layer Line Width

[Xiaoxun92]

Bambu Studio Version

1.9.1.67

Where is the application from?

Bambu Lab Official website

OS version

MacOS 14.5

Additional system information

No response

Printer

A1 Mini

How to reproduce

1. Import the attached Elephant Foot Bug Test.stl file. Note that the initial layer is very thin.
2. Set Line width -> Initial layer to 0.5mm, and set Elephant foot compensation to 0.3.
3. Slice the model. Observe the diameter of the initial layer's outer wall.
4. Reduce Line width -> Initial layer to 0.3mm, and set Elephant foot compensation back to 0.
5. Slice the model to refresh things.
6. With Line width -> Initial layer kept at 0.3mm, set Elephant foot compensation to 0.3mm again.
7. Slice the model. Observe the diameter of the initial layer's outer wall.
8. Set Line width -> Initial layer back to 0.5mm, while keeping Elephant foot compensation at 0.3mm.
9. Slice the model. Observe the diameter of the initial layer's outer wall.

Actual results

In step 3, the diameter of the initial layer didn't change in response to the 0.3mm Elephant foot compensation value.

In step 7, the Elephant foot compensation takes effect with a thinner Line width -> Initial layer.

in step 9, Elephant foot compensation still takes effect despite the Line width -> Initial layer has returned to the initial value.

Expected results

In step 3, if Elephant foot compensation is ignored when a wall is very thin, the user should ideally get a warning message about that.

In step 7, the outcome looks right.

in step 9, Elephant foot compensation should behave the same as in step 3. The discrepancy indicates a possible conflict bug between Elephant foot compensation and Line width -> Initial layer.

Project file & Debug log uploads

Elephant Foot Bug Test.zip

Checklist of files to include

• [ ] Log file
• [X] Project file

[QingZhangBambu]

there is the slice step: step 1: apply elephant foot compensation first, get the shrinked expolygon, Step 2: generate the wall with wall width. if the elephant compensation change, do step 1 & 2, so you get result in your step if only change wall width, just do step 2. so you get the result in your step 9 This is a bug that needs to be improved, but it involves the issue of how to use memory data, so it is difficult and needs to be discussed carefully.

[Xiaoxun92]

@QingZhangBambu Thank you for your comment!

From a user's perspective, I see two issues:

1. The elephant foot compensation setting can sometimes be silently ignored (as seen in step 3), which might catch the user by surprise. This is how I discovered this issue :joy:. I suggest raising a notification to the user when this happens (I assume the compensation is ignored intentionally in this case?)
2. With the same settings, the slicer generates different results (step 3 vs. step 9), which is clearly undesired. I assume this is the bug you were referring to.

[QingZhangBambu]

for issue 1:
if the outer polygon is too small, the elephant's foot will not be applyed. This should be written on the tooltip and will be improved later

[Xiaoxun92]

@QingZhangBambu Thank you! Please feel free to close this ticket when appropriate.