This design was created as an addition to Simple AMS stacking stand published by JesseZhang (thanks for the idea and high-quality model!). I made this reinforcement kit because I didn't think the original design was stable enough and would cause the top box to fall over.
This kit is fully integrated with the original design, easy to assemble and requires no additional tools.
Printing material - PLA, PETG
The photo shows a working (preliminary) version of the set, which does not quite correspond to the files published in this model, so these photos should be taken as photos for clarity.
if you want to make the structure even more rigid, just use two additional rods and fasten them with upper screws (in this case the nuts no more needed)