This is a 50mm puzzle cube. You will need to provide your own core and screws/springs from another cube. Although this is a mini-sized cube, the core is full size. I recommend using a YJ Guanlong core, as these can be found for $3-4 and this has been designed with that core.
Surfaces will need to be sanded smooth to allow best operation of the cube, and to allow the stickers to adhere properly to the sides.
The center caps may need to be adjusted to fit depending on your printer. I find them to be perfect fit with a standard quality print, but a bit loose with a high quality print.
This puzzle has been designed completely with open source software. Early development was done with OpenSCAD and FreeCAD. Final files were created in Blender.