Here's a simple standalone part that can help you keep a few things in one place. 

I printed mine from PLA with the 0,4 nozzle, 0,2 layer height, 20% gyroid infill, concentric top and bottom patterns. Had a little mishap near the top layer of the box bottom with a bit of missing material. Fewer walls and infill would work as well because at 20% it is already lightweight and unbreakable.

Designed in FreeCAD, model available for download.