Irregular wavy edges on top layer

[user_997469259]

Hello.
When I print rectangular parts, some of them appear with irregular, wavy edges instead of straight ones. This happens to me with parts with many edges and with straight edges.
I’m printing with matte PLA with a 0.4 mm nozzle and 0.2 mm layer. I’ve reduced the speed slightly, set the material to 101% when ironing, changed the print order of the walls, and activated the aracne, but i got the same result

. I used Bambu Studio and printed with the P1S with a standard nozzle. I’m posting a photo.
Thank you so much for your help!

[user_997469259]

No one has a reason of why this can happen? Why not all the straight edges are wavy? Faulty filament -maybe I must dry it-? Overextrusion? Underextrusion? Too much speed? Any help would be much appreciated!
Thanks!

[simon14]

@user_997469259

set the material to 101% when ironing

Can you clarify this? Is it 101% ironing flow?

Normally, it is only like this

Say, BBL PLA default flow ratio is 0.98 or 98%. You iron with 10% addition to 98% make it into 108%. This is 8% overextruded or overflow, and this extra 8% plastic has to go somewhere, yeah?

[user_997469259]

Many thanks for your reply!!
Ironing flow is set to 11% not 101%. My fault.
And Flow Ratio is 0.98.
Thanks!