This is an extended base and a battery box frame for the December 2018 Alien3d UFO box project. It is a truly great project but I couldn't fit the battery under the gear motor so I used Autodesk 123 Design to come up with a base that would hold the assembly high enough to place the battery under the gear motor. I also made a frame to keep the battery pack in place. I stuck everything together using 3dgloop.
Here's the link to Alien3d's December 2018 UFO box which has the project info:
3dGloop is marketed as an agent to help bond 3d prints to the glass print bed. I works great for this but also works great to bond two PLA pieces together. I applied a little to the battery frame and just put it where it needed to be and it stuck. I applied some to both the uprights of the new base and the bottom of the legs and set them in place. YOu probably can also use CA adhesive.