Slicing problem?

[3dnerd 6]

Hi,

I have a problem with a part I created and printed.

 

This is how it looks like in Cura:

 

And this is the printed result:

 

 

I printed Innofil PLA at 230° with following settings:

- Nozzle size 0.4

- Layer height 0.2

- Shell thickness 0.8

- Bottom / top thickness 0.6

- Fill density 10%

- Print speed 50 mm/s

As you can see in the Cura images the upper face where the inner small wall sits on is interrupted where the small wall starts.

The lower Cura image shows the 1st of three layers, there you can clearly see the small gap lines where the vertical wall sits.

Why Cura interrups the surface instead of creating a closed one?

I wish to have a closed face consisting of three layers and on top of this the small vertical wall should start. But as you can see it is not.

How can I get a closed surface before the small top wall starts to get printed?

 

In the photos of the print result you can see the gaps in the upper layer where the small wall starts. If the layer would be printed as closed surface then this problem won't come up.

How can I correct this and get a closed surface where the small vertical wall is printed on?

Thanks...

 

[dirkdirk 5]

You have to use more infill. Try 20-25%.

Also increase your top/bottom to 1.2mm.

[3dnerd 6]

Hi dirdirk,

 

thanks, yes I can do that. But I want to know why Cura does not create a solid, closed surface and on top of it the small vertical wall. Instead it creates a gap inside the surface - this takes longer and gives worse result as one can see.

I want to know if this is a slicing problem or if I can change my model somehow that this happens no more.

 

 

[dirkdirk 5]

I think this is part of the way Cura is programmed. The "gap" is the infill part. Cura only draws the perimeters and fills up the rest with infill. If someone can change this, Cura-God Daid is the one...

Instead you can print with 100% infill or change the infill to 100% for a few layers with the Plugin SwapAtZ. (Not tested, but should work)

Or just increase your infill and bottom/top and everything is fine ;-)

[yellowshark 153]

OK firstly let us look at your 4^th pic, the finished product from the top. The gaps close by the wall are almost certainly due to your .2mm layer and .6mm top/bottom layer – as dirkdirk has said and given the solution. You can see from your 2^nd pic that the base plate area has infill, which is why you are getting your problem on the top layers due to your settings.

Your 3^rd pic, showing the finished product from underneath, is more interesting. It should have a complete solid infill but it is clearly being affected by the wall, i.e. you “damaged” area is following the outline of the wall – which of course should start a number of layers further up. It would be useful to see a pic from the layer view of Cura showing layer 1.

My guess though is that the model was drawn by creating the base area first, then creating the wall, then placing the wall on top of the base area. In doing so the wall has actually been extruded into the base area rather than sitting on top. That is a guess though, it is not something I have ever seen before

Go to the advanced tab and then the quality section. There is a parameter there for “cut off object bottom”. Enter 0.5mm and then go back to layer 1 view; does it look better?

 

 

 

[3dnerd 6]

Hi Yellowshark,

thanks, just to make it clear, my posted Cura images show:

top pic: Cura 'normal' view

middle pic: Layer No. 17 (of total 40layers), the last layer below the solid layers (of the base plate) start

bottom pic: Layer No. 18, the first layer of the solid layers (of the base plate)

The upper small wall is not extruded into the base. The part was extruded from the bottom 'L' shape.

Then on the top face of that L I started another extrusion for the small top wall.

 

There is no pic from underneath. The upper phot is taken when UM2 did the last solid layer of the bottom part (layer 20).

The lower photo is the finished result similar to the Cura top picture I posted.