Small area flow compensation should depend on actual flow rate

[dewi-ny-je]

Is there an existing issue for this feature request?

• I have searched the existing issues

Is your feature request related to a problem?

Currently small area flow compensation depends solely on extrusion length, no matter the acceleration and the layer height.

As stated in #3334 this feature is a brute force approach to solve extrusion variability.

To make it work, and to make calibration meaningful, we should ask ourselves what causes it. Since now we have adaptive PA, any remaining issue of uneven flow on short extrusion length must be related, in my opinion, to non-constant extrusion rate, see
https://www.youtube.com/watch?v=XeMhQpcMrCA
which shows how many printers drop the actual flow rate already starting at 9 mm3/s. The issue is known for years, I just posted an example.

Which printers will be beneficial to this feature?

All

Describe the solution you'd like

I think the small area flow compensation should accept as input data the curve users can easily measure themselves, like in the video (weight or width approach), with
X=flow
Y=compensation needed in % (the difference between 100% and the actual %, so for example 0 up to 9 mm3/s, then increasing)
and the slicer should apply the compensation not based on extrusion length, but based on max flow achieved along each extrusion length.

So a short extrusion length at high acceleration and a long one at low acceleration should get a similar compensation.

This would adapt to various layer heights too, which the current one doesn't.

It should be made clear that this feature should be enabled after adaptive PA is enabled, since wrong PA for various speed/acceleration would cause similar issues, and PA is an easier to correct issue.

Describe alternatives you've considered

No response

Additional context

No response