Hi, every mesh that you are going to 3d print needs to be watertight, that mean that has to have thickness and needs to be closed(like a solid), I would recommend you to remove the spherical object at base of the structure.
Reduce the amount of subdivision that the pipe surfaces have, that makes the mesh to have a lot vertices that you don’t really need, and makes the STL file to work slower on the Slicer, turn off a lot of the components preview, they are not necessary, and makes the definition difficult to understand.
I personally wouldn’t use the surface pipe, they are very expensive geometries, you can use the mesh pipe component, is a lot nicer( I recommend you to search for a plugin that’s call WeaverBird for Grasshopper). The Mesh inside the yellow circle is the one to bake and to print, the 3d model is not at scale so when you added to the slicer is going to be very small.
parapluie-watertight.gh (60.8 KB)
This is not necessarily the finish object, because when I opened the original file, were some old components in the file and I couldn’t see them.