Voron Cube Tower Stacker

I'm printing a [Voron Test Cube](https://github.com/VoronDesign/Voron-2/blob/Voron2.4/STLs/TEST_PRINTS/Voron_Design_Cube_v7.stl) with every filament to see how it looks like. Also its a great way to check the retraction and speed settings.

So for store the cubes I modeled a "plug" to connect two of the cubes together. Since the cubes should be all identical a tower of test cubes can be build. For the first layer I also created a base to snap the first cube into.