What is the purpose of the Skirt option?

[terrypin 3]

Could someone explain Cura's 'Skirt' option please? What is the point of a rectangle a few layers high which is some distance away from the printed object? Is it just to allow you to test how well the initial layers are sticking, in order to abort the print if they are not?

[nallath 1,120]

Its to ensure that the flow is nice and steady before the print starts.

[terrypin 3]

Thanks, understood.

 

If a small part of the skirt is not firmly on the bed (either displaced a few mm, or lifted up, or both) is it recommended to always stop the print? Or wait a bit longer to see if the initial layer of the object itself looks OK?

 

On several occasions I've thought it looked right, but on gently brushing it with my finger it left the base. Would experienced users have left it alone or aborted, as I did?

 

[nallath 1,120]

I personally don't touch the print once it's started. If the skirt is completely loose i do tend to pull it off so it won't mess up the rest of the print, but that's it.

[obewan 37]

i use the skirt to fine tune the Z height using babysteps so as to get a good squish for the 1st layer

[terrypin 3]

Thanks both. It's only just occurred to me that instead of frantically trying to check out the skirt as it prints I should use the Ender 3 V2 Pause button? Although could that interruption have any possible side effects?

 

Or is the better solution more radical: to always do a set of simple single-layer prints first?

 

 

 

 

[nallath 1,120]

6 minutes ago, terrypin said:

Thanks both. It's only just occurred to me that instead of frantically trying to check out the skirt as it prints I should use the Ender 3 V2 Pause button? Although could that interruption have any possible side effects?

 

Or is the better solution more radical: to always do a set of simple single-layer prints first?

Most people just check the first layer. Pausing interrupts the flow which might actually defeat the purpose of the skirt.

[terrypin 3]

Thanks, understood, that makes sense.

 

[GregValiant 1,251]

"...Ender 3 V2 Pause button? Although could that interruption have any possible side effects?"

Using the Pause function on the Ender LCD may shut down the heaters (it does on my 3 Pro) and the default "Disarm Timeout" for the steppers is 120 seconds.  If you aren't really quick, it takes longer than two minutes to re-heat and the steppers lose position, and at that point the print is scrap.  So using the Pause function needs to be practiced so you have some idea of the side effects and limitations.  Adding an M84 S1800 to your start gcode will give you 1/2 hour before the steppers time out, but the heaters shutting off is in the firmware routine that the Pause button calls.  (At the end of a print - when the steppers get disabled the disarm timeout resets to 2 minutes.)

If you are forced to Auto-Home an Ender during a print, there will likely be a layer shift of maybe .5mm because of position repeatability errors in the end stop switches.

 

I usually run my skirt at 3 loops and if there are issues with adhesion of the skirt (like if some dummy forgot to clean the build surface) then I abort.  In my case, the problem is almost always lack of preparation of the build surface which isn't going to get better by itself.

[terrypin 3]

Many thanks, much appreciate that helpful practical advice, which I'll pursue.

 

Do you manually clean the base before every print? I've so far just made a visual inspection and peeled off any filament, usually on the left edge. Plus a wipe down with a damp cloth every few days.

 

[GregValiant 1,251]

Before every print with isopropyl alcohol.  It takes about 5 seconds and is cheap insurance.

If I'm printing PETG it then gets a light coat of AquaNet Super Hold hairspray after cleaning with IPA.  It's what works for me.