A different approach to an age old problem - how to store, transport and protect a standard size 3x3 Rubic's cube.  This one is sturdy and the latching mechanism has a nice positive click to it. 

This prints in place with no supports.  I use 3 wall loops and 15% grid infill.  I have printed it in PLA and PETG with good results.  Sometimes a raft or brim helps.  The Bambu H2D works fine without.  My Kobra S1 works best with a brim.  The Kobra 2 plus seems to work fine without raft or brim.

I have printed the standard fit holder (cube_holder_std_fit.stp) on Bambu H2D, Anycubic Kobra S1, Anycubic Kobra 2 Pus, and Flashforge Adventurer 5M Pro without any problems.  When I tried it on a Creality Ender 3 V3 SE however, it didn't work as well owing to the hinge fusing to itself and then breaking when I tried to work it loose.  So I made the second model (cube_holder_loose_fit.stp) with looser tolerances and it works fine.  If your printer doesn't do the standard fit model well, then try the loose one.