And another try:-)
Voronoi -> Split base plane -> select naked edges -> copy - paste -join - delCorners - explodemove (thanks Pilou:-))- extrude tapered with negative angle - select solids - union - substract from a cube | 5min fun!!! Then try to blend/fillet erverthing -> a nightmare - not only in Moi3D;-)





Have a nice day!
Karsten