STL file which has been sliced successfully on Cura before, now when re-sliced shows wall errors/no walls

[MagsE8088 0]

Hello,

 

Hope you can help me understand better how Cura works and if there are any issues with the program that have been experiences these past few days by others.

 

I purchased a 3D printer a month ago and for the past month I have been creating a few 3D cookie cutter designs in Fusion 360, then been printing them using an Ender 3 V2 . All was fine till last week, when I sliced a design on Cura and the preview showed all the internal walls were missing. I thought Cura might needed updating, which I did and updated to the latest version from 4.13 to 4.13.1, but wasn’t a 100% convinced that was an issue. When I tried slicing again, the same mistake appeared. I then tried ticking the "Print Thing Walls" and that didn’t look right either. I then tried re-slicing a file I have printed successfully just a couple of days before and that went terribly wrong too, the walls were not showing either.

After doing lots of online reading and research, it seemed that the problem was that my designs had walls that were too thin, which I kind of get. But what puzzles me is that if it was slicing successfully just the day before, why won’t it do that again for the same file?

I have attached the SLT and OBJ file and the G-Code for those designs that worked previously and G-Code once re-sliced again as well as images of the recent items I printed successfully.

I redesigned a couple of cookie cutters, making sure that all the closed-in lines are wider that 0.4 (that being the nozzle size on my printer). When it came to slicing some models, to my shock, Cura won’t slice the end of the cutting part of the cutter which I always, always had set at 0.5 and never had an issue with.   I had to change that size to 0.6 just so it would slice again. I have attached picture and file as well. This just doesn’t make sense to me.

I haven’t changed any of the settings prior to all this happening, I don’t think I’ve done and changes even accidentally. I have checked that all the basic settings are as they should be and as you can see I am not creating complicated 3D prints. I have tried using both standard and dynamic settings on Cura and only last night for the first time ticked on "Make Overhang Printable". Please could anyone explain why is this happening? Is there a bug somewhere? Why would it slice well for so long and then all in the sudden no longer accept the wall sizes? Why won’t Cura slice a 0.5 size wall now when, when it had no problems doing it before? Also, starting a print today, I noticed that while it used to start by printing a uniform 3mm base, and then proceed printing the rest of the inner walls a a further 3mm, now it appear that it is starting to print the inner walls, in some areas, from the bottom up

Hope you can help me figure this out, any help and advice welcome. Wasn’t expecting the 3D printing to be so temperamental, but I really hope I can get to the bottom of this as I really was enjoying it.

 

CE3PRO_Eastereggstmp12 v1 Error.gcode Eastereggstmp12 v1.obj Eastereggstmp12 v1.stl 373324297_CE3_6Eastereggsfile.gcode

[DivingDuck 105]

Check for Print Thin Walls.

[GregValiant 1,330]

I don't know guys.  I opened the "EasterEggStamp" STL file in Cura.

The walls of the hearts are really thin and they go through the initial layers weird.  So I uploaded the file to an STL repair site and got this report:

--> 0 Naked edges (?)
--> 0 Planar holes (?)
--> 0 Non-planar holes (?)
--> 1492 Non-manifold edges (?)
--> 2676 Inverted faces (?)
--> 0 Degenerate faces (?)
--> 49 Duplicate faces (?)
--> 0 Disjoint shells (?)

-> Repairing: 100.00%

----- Repair completed in 29194ms ------
-> Vertex count changed from 30339 to 27849 (-2490)
-> Triangle count changed from 63266 to 55702 (-7564)

This makes me think it's a boolean thing that occurred in Fusion.  The pieces parts weren't "unioned" correctly?

 

@MagsE8088 the model errors aside - there are a couple settings you can look at.  Make sure the "Outer Wall Inset" is 0.  You might try setting the Hole Horizontal Expansion to -.1.  I did get it to slice correctly like that.  The image is of the "unrepaired" model with 0.2 layer height, 0.4 line width, HHE -.1.

A project file is the best to troubleshoot.  If you use the "File | Save Project" command and post the 3mf file that would be good.

 

 

Edited March 8, 2022 by GregValiant

[DivingDuck 105]

Good catch @GregValiant. I turn of Meshtools last week and forgot to reverse that later on and I think too that there is something wrong with how the bodies was build in these Model.

@MagsE8088, maybe you want to attach the Fusion360 design file here? I'm sure that this problems can be fixed easily in your model on first place.

 

[MagsE8088 0]

Hello,

 

@GregValiant I can only say THANK YOU, THANK YOU, THANK YOU SO SO MUCH! I think and hope I have successfully sliced a model which is currently printing after applying those changes.

 

I now make sure that the walls of any SVG file I import in Fusion 360 get outset slightly when I trace bitmap, however @DivingDuck you are right, when I try to extrude some areas I do get a Geometry Error. To bypass that the only solution I could came up with was to hide part of the body and then extrude and unhide the body again. Any better way to do the extrusion is welcome tho. Does this link work https://a360.co/3CErXFL.

 

Thank you both so much for your time, really appreciated.

[GregValiant 1,330]

For the hearts: I would extrude the solid heart, edit the sketch and offset all lines .5 to the inside, and then make those offset lines a new sketch and cut out the center of the heart with it.  That will leave the walls as you want.  You could also use the Shell command to make them hollow and have the program ignore the top and bottom surfaces so they stay open.

 

When you have to use splines in a sketch there can be problems as the geometry is tough for the software to describe mathematically.  Better to use polylines and /or arcs and circles.

Lofted features are OK until you go to cut holes through a lofted surface.

 

For the most part we don't see a lot of issues with models created in Fusion 360 (unlike Sketchup or Blender models).  You'll learn what works and what to watch out for as you go along.

[DivingDuck 105]

@MagsE8088, I can't open the link. I have no permission to access your linked address. You need to do something like this:

 

and share the password with me. Alternatively you can attach the fusion file or send me as pm. (Export, select Type: Fusion Files (*.f3d)).

[MagsE8088 0]

@GregValiant I am going to give that a go, thank you! Experience makes perfect and as you say I will figure it out as I go along. Not giving up.

 

Thank you so much for the immense help.