Surface Mode Surface and Surface Mode Normal travelings

[websurfer 1]

I am working on a part to print with LW-PLA. It's crutial with this plastic to minimize traveling outside the model becouse of crazy stringing.

I found out it works out with Surface Mode "Surface". I nearly have no traveling outside the model and final part was printed almost without strings.

 

Now I need to change surface mode to normal, with same options I am having result completely different. 

 

Is there any way to achieve result alike first one but with Normal Mode?

FV_fuse01(2mm).3mf

[websurfer 1]

Also, I've tried combing modes but it  has no effect at all

[Slashee_the_Cow 271]

Combing only changes what it will avoid when travelling inside the model, not in an air gap.

 

Part of the problem is that you're getting a little bit of skin, even in these columns where you don't need it:

Even at the back column:

That's what's causing one set of travels back and forth. It does all the walls then all the skin:

If we lower Top/Bottom > Skin Expand Distance then it no longer generates skin in these areas:

But then we have a problem at the angled bit: it expands outwards more than one line width per layer, so we end up with holes:

But even with the project as you had it, there's still this effect a little bit:

 

So what can we do here?

Having your layer height be a factor of your line width (or vice versa) never hurts. Here it is with a 0.2mm layer height:

The effect is still there, but it's a bit lessened.

 

Okay, so at this point we're probably barking up the wrong tree: why is it generating skin on the inside in the first place?

I... honestly don't know. Your model isn't watertight, but I fixed that and it's the same.

Hold on, what's this I spy?

Those are tiny gaps at the bottom.

And they go the whole length up the side of the column. Could this be the problem? It might want to generate skin because it's exposed to the air.

So I just did a brute force merge vertices. It closes the gaps at the top and bottom:

Though if I zoom in close, there's still gaps in some places in the columns:

But has it helped?

A little bit! It's only generating the skin on one side where there's gaps. I tried increasing the threshold on merging vertices, but that just removed detail, never closed the edges. So why not. I try a different close holes method and it complains about having non-manifold faces. So what happens when I remove non-manifold faces?

Cross section from the middle of one of the columns with the vertical hole in it. Ouch!

Umm... so zoom out:

TRIPLE OUCH!

 

So basically... the problem is your model. Depending on what program you used to make it you might need to find the right settings to get it to generate a good quality STL.

[websurfer 1]

Thank you a lot for such a detailed answer! It was funny to read 🙂

I found out it minimize travels with Thin Walls option enabled. I don't know why, but it worked out. Anyway, Combing option is not make any difference in any of configuration I tried. I've found a lot of discussions about Combing option weird behavior in Cura >5.0, so I've tried to use Cura 4.13 and Combing made the trick even without Thin Walls option almost without traveling outside the model and stringing.

[Slashee_the_Cow 271]

8 hours ago, websurfer said:

Thank you a lot for such a detailed answer! It was funny to read 🙂

I found out it minimize travels with Thin Walls option enabled. I don't know why, but it worked out. Anyway, Combing option is not make any difference in any of configuration I tried. I've found a lot of discussions about Combing option weird behavior in Cura >5.0, so I've tried to use Cura 4.13 and Combing made the trick even without Thin Walls option almost without traveling outside the model and stringing.

Great to hear you seem to have figured out a solution that works for you and hopefully you've learned a few things along the way 🙂. 3D printing is mostly an experience thing, you don't start knowing how to do everything, you learn a bit almost every time you print (even I'm still figuring out new stuff as I do it).