Thank you so much!
Below I quote the full process of setting up custom print bed.
I would also like to add a simple solution for positioning the bed model (this question occurred in the linked topic).
What I did was (in SolidWorks) to create a new coordinate system and positioned it the same way as origin in S3D, then I saved the .stl with the new origin. It imports in S3D perfectly.
You would want to put the file into the folder:
Then go into Simplify3D and go to File-->Export FFF Profile. Then open that file up with a text editor.
Find the two lines:
Change those to:
Where myPrintModel.stl would be the name of your file.
Then save it, and go to File-->Import FFF Profile.