What Are Skirts For?

[CrazyIvan2 1]

OK, basic question and the answer must be here somewhere (I did look)... what is a skirt for?

 

Here's my understanding (corrections welcome):

 

Raft: sets up a buffer between the print bed and the first layer of the model, which can be optimised for bed adhesion.  Also eliminates any unevenness in the bed.

 

Brim: increases the surface area of layer 1 in order to improve adhesion, without getting between the model and the print bed (improving layer 1 surface quality and reducing filament waste).

 

But skirt?  It's like a brim but does not contact the actual layer 1 print, so how is that supposed to increase adhesion?  And if it's not intended to increase adhesion, then what is it for?

[PizzaTijd 13]

In my experience it just makes sure that your print head is primed; that the material is all ready to go, as it has already extruded the skirt before moving over to the print.

[Dustin 160]

You can find some documentation about it on the knowledge base
here: https://support.ultimaker.com/s/article/1667417985477

[CrazyIvan2 1]

Fair enough, so calling it "bed adhesion"  is something of a confusing misnomer!

[GregValiant 1,342]

Before there were so many ABL's available you could watch the skirt go down and make on-the-fly adjustments to the leveling wheels.  It would need to be a bigger print to be effective but it does work.

[CrazyIvan2 1]

What I'm hearing is what the skirt setting can be used for.  I'm still hoping for a convincing explanation what was in the designer's mind when skirts were invented.

 

"What we need is a gash print to start off, so that if the user is really quick they can get in and tweak the manual bed levelling on the fly before the real print starts instead of doing a proper levelling before starting the print."

 

"Tell you what, instead of extruding some filament in space or as a blob to ensure the nozzle is primed, let's draw a perimeter around the actual print."

 

Those are printer-specific things, which are normally confined to the printer config rather than the slicer settings.

[PizzaTijd 13]

The reason it was 'invented' was exactly for the reasons it can be used for. It's not a mandatory setting.

If you don't want or have to use it, don't use it.

 

You just know the scenarios now where it is applicable.

[CrazyIvan2 1]

I don't think screwdrivers were designed for levering the lids off tins of paint, but...

[Travis7s 26]

Personally I think skirt is a much nicer way to prime than a blob or extruding in space. Less "mess" inside the printer enclosure and blob especially becomes a liability because it can get dragged by the nozzle or sometimes people forget to remove the blob and you start getting blobs on top of blobs.

[CrazyIvan2 1]

Sorry to keep banging on about this but everybody appears to be missing the point: skirts may be for priming the nozzle, but it is listed under "build plate adhesion"!

 

I can accept that raft, brim, and skirt are mutually exclusive and therefore skirt has to be an 'adhesion' option, but not even the hover tips mention skirt is for priming the nozzle, so I'm sure you can understand why I don't find it intuitive.

[PizzaTijd 13]

A poorly placed first layer, because the material wasn't primed yet, causes worse adhesion.

Therefore a skirt will provide better build plate adhesion.

Edited November 15, 2023 by PizzaTijd

[Dadkitess 19]

This. Plus, why not having it around your future 3d print so that you don't forget to remove it. I don't like the prime band on PrusaSlicer for instance because it is easy to miss and it's so thick that the head can really force onto the previous prime extrusion.

 

And if it's around the future part, then it's also the occasion to see if the first contours will print well or if does not stick well exactly at the place of the print : grease / deformed plate can be heterogeneous.

 

All of that to ensure that the first layer will be as good as possible, let alone Brim and Raft, and so... In the Bed Adhesion category. And it would not fit better elsewhere, would it ? ^^