Mini transparent printing test cube with embedded sphere

This is a small solid cube with a spherical void inside it. This is useful to find good settings to obtain a truly transparent print on FDM printers before trying something larger and more advanced like [cymon's skull dice](https://www.thingiverse.com/thing:2236613).

I also provide a model with small drain holes if you want to print this on an SLA/DLP printer (where obtaining true transparency should be quite a bit easier than on an FDM printer).

The print shown is transparent ABS, but any transparent filament should work if you do the following things:
* 100% infill, obviously
* Print with a bit of over-extrusion (not too much, just enough to ensure air bubbles are pushed away from between the layers)
* Print slowly
* Print hot, with just enough cooling to keep the print from turning into one messy blob.
* Printing in thin layers may help as well.

Natural PLA should also work to a certain degree, although its transparency is limited and will look milky for thicker object