Move exceeds maximum extrusion (1.203mm^2 vs 0.640mm^2) on print start

[Taff-The-Beard]

Keep getting "Move exceeds maximum extrusion (1.203mm^2 vs 0.640mm^2)" on start of print just before the extruder goes for a purge line. I've doubled checked the start print/end print/ before and after layer change lines copied correctly in Super Slicer but no joy.

I've read elsewhere about work around in disabling a saftey feature but don't wanna go down that route.

Any ideas?

EDIT: I’ve removed the suggested start/end and layer change G-codes and it now runs. I’m still after a little help as to why these aren’t working for me.

klippy (4).log
moonraker (1).log

[ovar0409]

I've got the same kind of error "Move exceeds maximum extrusion (1.804mm^2 vs 1.440mm^2)"... 1.44 because my nozzle is 0.6mm (Maximum Extrusion = 4.0 x Nozzle_Diameter^2).
I'm using variable_start_purge_length: 30 and variable_start_purge_prime_length: 12.0, I guess it's not correct....

[ovar0409]

I increased variable_start_purge_length to 50 but it had no impact. I still get the exact same message "Move exceeds maximum extrusion (1.804mm^2 vs 1.440mm^2)"

[jschuh]

Just set max_extrude_cross_section to a more reasonable value in your Klipper config. You should be fine with 3.0, which is about twice Klipper's default for a 0.4mm nozzle. I personally set it to 4.0, but that's because I don't want to have update my Klipper config anytime I swap in a larger nozzle.

For a bit more context, Klipper's max_extrude_cross_section limit is intended to catch slicer errors (e.g. mismatching relative vs absolute extrusion modes), but it defaults to such a low value that it triggers in normal printing operations (priming/purge moves, taller layer heights, larger extrusion widths, certain arachne moves, etc.). Setting it a bit larger will still catch the real slicer errors, but you won't have prints spuriously aborting in normal operation.

[Taff-The-Beard]

Awesome sauce!!! Thank you so much! You’re a star!

[goegsig]

I got the same error. Thanks for the solution-

[ovar0409]

I read about that parameter, but I was not sure about the value to use.... and before changing it I wanted to understand a bit more. Thank you,