Inconsistent/odd, or shifted support layers (hard to describe, see photos)

[wdwms 2]

I've been seeing this for a few versions now; regardless of the model I'm printing. it starts to compute these really odd layers and won't just print a tower straight up w/out shifting or changing the tower shape on a few layers. Because it's causing bridging its causing stringing and other issues w/my PVA support.

 

Thoughts? Thank you!

 

S3 and is cura v 5.6..

 

 

[Slashee_the_Cow 276]

Could you please post the Cura project file (.3mf, in Cura get it ready to print then go to File > Save Project) so we can have a look at it? Unless someone is a support guru and can figure it out by the screenshots it's a lot easier to try playing with the settings.

[wdwms 2]

Sure not a problem. Project file attached here

 

arms.3mf

[Slashee_the_Cow 276]

Weird. I load the file and it's using gyroid support and looks normal. Are these the support settings you're using or did something get lost in translation?:

 

Although my first guess: it's worth noting that when you have Support Infill Layer Thickness set to something different to your normal layer height, it can look weird and and a bit thick in the preview, but it prints fine. Try turning that down to 0.1mm and if your support looks normal, then it'll probably print fine at 0.2mm.

[wdwms 2]

Oh i must have saved it on Gyroid, i was trying a few different settings. Try it on normal, tell me if this is what you see:

[Slashee_the_Cow 276]

TL;DR: You need make the following changes to your settings:

• Connect Support Lines off
• Support Horizontal Expansion down to 0.7mm
• Support Join Distance to 0mm

Thorough detective work below, if you want to see how my brain approaches this problem.

 

Okay so if I set the support layer thickness to 0.1 it still does it, but not quite as bad. This means it's not just a weird display thing.

So the problem is that for most of the layers it's drawing this pattern:

But sometimes it's drawing this which has a few extra lines:

 

My first thought was "horizontal expansion + expanding object = sometimes it rounds up to draw a little bit extra. But no, same problem with horizontal expansion set to 0:

 

Then I realised "hang on, those bits are creating a perimeter". Turn off Connect Support Lines and it's (mostly) gone:

You don't really need to connect the lines when you have a grid that dense anyway.

 

But why the little bits which it's trying to print in midair?

Then I think "the lines are sorta close together... it can't be trying to join them, can it?" *sets Support Join Distance to 0*

Apparently it can be trying to join them. I suspected that that wasn't the root cause of the problem, so flipped Connect Support Lines back on for a quick test.

I think the join distance problem is actually a problem created by removing those extra connection lines. I could see that setting the join distance to 0 created a few orphaned bits though, which are bad because they're likely to topple over and don't contribute at all structurally. *sets Support Join Distance to 1mm*

Now it's just trying to join in midair some of the lines which are getting closer as the support curves seriously inside.

Oh, but it still left at least one orphan:

Hmm, that orphan is right on the edge... if I just move the edge slightly in... *sets Support Horizontal Expansion to 0.7mm so it shouldn't try creating two extra walls where they might not be needed*

Yay! No more orphans.

 

So now with that cocktail of changes, how's it look?

It looks like any self-respecting support should.

 

So, in case you forgot them during my rambling, the changes you need to make are:

• Connect Support Lines off
• Support Horizontal Expansion down to 0.7mm
• Support Join Distance to 0mm

 

Detective work over.

[wdwms 2]

Thanks! i'll give this a whirl!