circles getting closed in cura

[Areyan 0]

so im pretty new to 3d printing and ive made this row of circles (in shapes of hexagons) in blender, when i put it into cura it closes the circles close to the to when it finishes. i want the entire thing exactly as it looks like on the prepare tab picture i included (hole from one end to the other). also when i try to put in 1 hexagon at a time it still fills in the inner space, couldnt find anything online to fix this. please dont use any big technical words im new to this world.    

[gr5 2,167]

Please post your project file so I can see what's wrong.  It could be the model.  Or it could be settings.  If you post the project file I can see both.

 

Do "file" "save project...".  Post that file here.

 

 

 

[gr5 2,167]

Hello?  Still need help?  I'm going to guess your normals are backwards for those inner walls.  And that means you are probably using sketchup.  Am I close?

[Areyan 0]

1 hour ago, gr5 said:

Hello?  Still need help?  I'm going to guess your normals are backwards for those inner walls.  And that means you are probably using sketchup.  Am I close?

i am using blender but where do i use the file options

 

[Areyan 0]

sorry this is only the stl i cant but the .blend file in. if there is any you want me to export it as tell me

hexagon test rings.stl

[gr5 2,167]

In cura click "File" in the top left corner.  It's a menu item.  Then "save..." for older Cura and "Save project..." for newer cura.  Please post that file.

[gr5 2,167]

So I looked at your STL file.  The normals are all messed up.  There is a Cura plugin that fixes normals - I tried it and it worked great on your model.  blender is one of those programs that let you reverse the normals (put the walls inside-out) which confuses cura.  Here's how to fix them in Cura (but there are also ways to fix them in blender but I don't know much about blender).

 

In the upper right corner of Cura click "marketplace" and make sure you are on the "plugins" tab and install "Mesh Tools".  Then restart Cura.  Now right click on your model, choose "mesh tools" and first choose
"check mesh", then "fix model normals"

 

[gr5 2,167]

Oh I found this:

if using blender - here's how to fix your model
I went into edit mode with the object in Blender 2.83 and pressed "a" which selects all faces / vertices / edges, depending on what select mode you are in. The entire object should be highlighted. I then went to "Mesh" (see images), went to the "Normals" section, and selected "Recalculate Outside". This probably will not fix any edges that are not merged, but it will fix the faces that are inverted on the object. 

[Areyan 0]

13 hours ago, gr5 said:

Oh I found this:

if using blender - here's how to fix your model
I went into edit mode with the object in Blender 2.83 and pressed "a" which selects all faces / vertices / edges, depending on what select mode you are in. The entire object should be highlighted. I then went to "Mesh" (see images), went to the "Normals" section, and selected "Recalculate Outside". This probably will not fix any edges that are not merged, but it will fix the faces that are inverted on the object. 

thank you so much, been a lot of help.

[Areyan 0]

14 hours ago, gr5 said:

 

hexagon test rings.stl

 

once again i have a problem. i put the second part onto my design and it seems to close 2 of the spheres near the last few layers how can i stop this i just want 2 spheres in the middle 

 

[Areyan 0]

hexagon test rings.stlsorry i forgot to add the flooring to that this is my final file, it still does the same thing though (closing the sphere)

 

[tinkergnome 927]

Still a lot of mesh problems...

A lot of faces with wrong normals and the walls of the spherical things in the middle have no thickness.

 

I think there are plenty of tutorials out there about how to use Blender together with 3D-printing...

At least you should activate the "3D printing tools" plugin and always check the model before exporting it.

And be absolutely sure that there are no doubled vertices and no overlapping faces and all that... Basically - always do all the "standard" checks for a good mesh topology...

 

Good luck!

 

 

Edited March 26, 2021 by tinkergnome

[Areyan 0]

1 hour ago, tinkergnome said:

Still a lot of mesh problems...

A lot of faces with wrong normals and the walls of the spherical things in the middle have no thickness.

 

I think there are plenty of tutorials out there about how to use Blender together with 3D-printing...

At least you should activate the "3D printing tools" plugin and always check the model before exporting it.

And be absolutely sure that there are no doubled vertices and no overlapping faces and all that... Basically - always do all the "standard" checks for a good mesh topology...

 

Good luck!

 

 

 

thanks i think i have done it all and ready to print thanks for the help (both of you) 

[Areyan 0]

1 hour ago, tinkergnome said:

Still a lot of mesh problems...

A lot of faces with wrong normals and the walls of the spherical things in the middle have no thickness.

 

I think there are plenty of tutorials out there about how to use Blender together with 3D-printing...

At least you should activate the "3D printing tools" plugin and always check the model before exporting it.

And be absolutely sure that there are no doubled vertices and no overlapping faces and all that... Basically - always do all the "standard" checks for a good mesh topology...

 

Good luck!

 

 

just 1 more thing how can i change the settings so this thing isnt at the bottom of my build. (the circle at the floor of the build

Edited March 26, 2021 by Areyan

[Areyan 0]

actually would that bottom layer even print, maily i dont want the hexagons to connect, becuase i dont remember that being there in my other prints

[gr5 2,167]

Sorry I'm too lazy to open the STL but I think your print isn't quite flat on the bottom - the left sphere is sticking down slightly and it's printing that circle as a brim around the base (if you switch your color options in cura PREVIEW it will show skirt as a different color than the rest).

 

One quick fix in cura is to lower the part down into the glass.  But that is disabled by default so first go to cura preferences and uncheck the box "automatically drop models to the build plate".  Then click on the part and use the move tool and set the Z value of the part to -0.1 or more until it prints the entire part on the bottom layer.

 

Of course ideally you would have the bottom spheres perfectly lines up with the rest.  I mean perfect within 0.01mm.

 

[ahoeben 1,948]

1 hour ago, gr5 said:

One quick fix in cura is to lower the part down into the glass.  But that is disabled by default so first go to cura preferences and uncheck the box "automatically drop models to the build plate". 

You don't have to uncheck the "automatically drop models to the buildplate" option to move models below 0. That option only affects models that float above the buildplate, not those that are sunken into the buildplate.

 

  

1 hour ago, gr5 said:

I mean perfect within 0.01mm.

It should really be perfect within 0.00000 mm (ie: exact). Otherwise the bottom is not "flat" for CuraEngine.

Edited March 27, 2021 by ahoeben

[gr5 2,167]

On 3/27/2021 at 12:49 PM, ahoeben said:

It should really be perfect within 0.00000 mm (ie: exact). Otherwise the bottom is not "flat" for CuraEngine.

I thought if the initial layer height is 0.2mm and the bottom of the part is flat within 0.2mm then it the bottom most slice will be 0.2mm from the bottom of the part and it will slice fine.  Right?

[ahoeben 1,948]

No, AFAIK the first (initial) layer is an intersection of the model at z=0. The next layer is an intersection at initial layer height.

 

Edit: Actually, I am not 100% sure about this. CuraEngine is not my area of expertise, but this is consistent with the behavior I have seen; if the bottom is not 100% flat, the initial layer will be partial. @ghostkeeper, @bagel-orb and @burtoogle will know for sure.

Edited March 28, 2021 by ahoeben

[ghostkeeper 105]

The real answer is that it depends on the Slicing Tolerance setting. But going by the default of "Middle", it would create a cross section from the middle of the Initial Layer Height. So if your Initial Layer Height is 0.2mm, it would create a slice at Z=0.1mm.

 

Thus, you'd need to make sure the bottom of that sphere protrudes by less than 0.1mm.

[bagel-orb 61]

I thought that for the slicing tolerance of middle it slices all normal layers in the middle, but the initial layer at an offset.

 

Example:

0.1mm layer height, 0.2mm initial layer height gives layers at the heights:

0.15 0.25 0.35 0.45 0.55

 

So the initial layer is sliced at a height of half the normal layer height below the initial layer height.

[ghostkeeper 105]

No, the initial layer is also sliced through the middle of its Z range:

 

https://github.com/Ultimaker/CuraEngine/blob/991cd026ffccc6def5e5b6a937edd6ae1b7cc8bf/src/slicer.cpp#L957