I did youtube videos and a Web page to give more informations on how to print it and to modify it with FreeCAD.
Links to my Web page giving more explanations :
https://www.gisinb.ch/yt/impression3d/portal/portal.html
Youtube video in French :
Youtube video in english :
The author remixed this model.
I completely redesigned the Portal, in FreeCAD. The basis, top and bolt are squares. I added a kind of support to help the 3d printing.
This is a smaller version.