Overextrusion nightmare after Cura to PrusaSlicer swap!!!

[cb.neil.86]

I just swapped from using an old, reliable profile in Cura to PrusaSlicer, and now every single print is a DISASTER! My Benchy looks like a melted snowman. It's got huge zits, the corners are bulging, and the top layers look squashed and messy!!!

I'm printing PLA at 200C on an Ender 3 Pro. I've already checked that my E-steps are calibrated correctly on the printer itself. I matched the filament diameter to 1.75mm in PrusaSlicer. I know the key setting is the Extrusion Multiplier, but the default for my profile is 1.0.

What value should I start with to bring this flow rate down? Are the default PrusaSlicer profiles generally set too high, or is there a hidden setting I might have missed that's forcing too much plastic out? Any advice on a quick fix, like a flow number to try, would be a lifesaver. Thanks!!!

 

[Huxter]

Welcome! That sounds awful!

First off - make sure you are starting from the .stl file - NOT a 3mf, obj... Try Benchy again w the stl file, and take PrusaSlicer defaults for your printer.

Good luck!

 

[Alan]

You’re close! Try setting flow to 95% and reprint a small cube. Most Ender profiles in PrusaSlicer need that little trim. Once it looks clean, lock it in and you’re golden. Remember most printers have their own quirks, do small adjustments!

 

[MikeHenry]

On my Prusa Core One and XL I use an extrusion multiplier of 0.93 for PLA. My Mk3 and Mk4 needed the same setting. There are several calibration prints on Printables that can be used to establish a good extrusion multiplier for your printer. Here's one, similar to the one that I use.

https://www.printables.com/model/738843-gridfinity-bin-and-extrusion-multiplier-calibratio

and here's Prusa's approach to calibrating the extrusion multiplier:

https://help.prusa3d.com/article/extrusion-multiplier-calibration_2257

There's lots of good help in Prusa's Knowledge Base.