SOLVED Problem with area of the object

[Aelban 1]

Good day to everyone ,i have this problem, when I load a model in cura I often have these grey thin lines that

define the area of the object to print with the only problem that the area is the one of the yellow object itself,

i want to print only the yellow object but the printer cosider all the space between thin lines and the object as an area to print ,so I have problems

to give dimensions to the object!How can I delete the grey thin lines so the printer consider only the yellow object as an area to print?

[gr5 2,172]

I'm not sure but I'm thinking maybe those lines are in your cad model?  I think maybe you have a "plane" under your model defined by those 4 triangles shown with dashed lines. 

 

Can you post your project file please?  Do "file" "save..." and that saves your project file and then you can post it here.  Project file will contain your STL plus your printer settings, profile and more.

[ahoeben 1,948]

The model was imported as a group. Select the object, right-click it and ungroup it.

 

Alternatively, export your model as an STL instead of as a 3MF file, and this "grouping" should not happen in the first place.

[Aelban 1]

Thanks to your advices I solved the problem ,I had to ungroup the models and then to group them again

to cancel these lines

thanks guys