So I finally made a base for my 3-path dice tower v.2:(https://www.thingiverse.com/thing:1271858). No more flying dice, Maybe.
I went with a gothic arch theme for the retaining fence. I LOVE the cut stone dungeon tiles by devonjones (https://www.thingiverse.com/thing:1882293) with the OpenLock connector option, so I made sure my base also used those features. The connector clip is found in https://www.thingiverse.com/thing:1833963/#files.
I used Autodesk Fusion 360 exclusively for this. I've included the .f3d file to enhance your remixing pleasure. :)
I'm also uploading the .stl into my 3-path dice tower page.
2017-07-19 update: The fence and opening now has brick-like texture.
2017-07-20 update: I quartered the base for smaller printer beds, and cut OpenLock holes to allow them to be locked together.
2017-08-01 update: There's now a poorly-shot video of the tower & base in action here: https://youtu.be/UM9lduOIe2k