S-curve acceleration?

Is s-curve acceleration on by default in the pre-built binaries?

If not, how do I enable it? or do I need to compile my own binary?

It is enabled by default in latest releases.

So apparently S-curve and linear advance don’t play well together.

Are there instructions anywhere on how to compile a custom build? I’ve built Marlin from code before, but that got flashed via direct USB connection, not microSD…

Nevermind. I found the build from source instructions.

Do you have some sources for that? Do you disable S curve?

Yes see discussion here:

[BUG] Linear advance incompatible with S-Curve acceleration · Issue #14728 · MarlinFirmware/Marlin · GitHub - https://github.com/MarlinFirmware/Marlin/issues/14728

The short version is that linear advance expects trapezoidal acceleration, which is the default without s-curve. Some people say “LA + s-curve” is better than “no s-curve and no LA” but not as good as “no s-curve with LA”.

I may try to build my own advi++ without s-curve sometime this week to try it out.

By default, ADVi3++ uses a K factor of 0, i.e. no linear acceleration. So by default, S curve should be OK.