I have been slowly getting back into "physical audio" - that's my term for Vinyl and Tape-Cassette, what many would call "retro" (it isn't retro for me, it is what I used to have music on before digital became a thing ;)).
One thing I haven't had is a way to hold my slowly growing DIY tape collection so I designed this solution.
There are two main parts, the Base and the Extension. The Base is 5 cassettes high while Extensions are provided in 1, 2, 3, 4 or 5 cassettes high, allowing to make full use of your space. The Extensions are designed to be glued to the layer below. The Base has positions on the bottom for 6mm rubber feet to be attached.
As such you will need to print the Base and then any number and combination of the Extensions for the size you require.
Also provided is a test piece that you can use to check that your machine will be printing to the right tolerances.
The wall thickness (1.6mm) has been designed for my printer which uses a 0.4mm nozzle. At the 0.3mm layer height (using Slic3r) this is enough to give 2 perimeters with no infill needed, aside from a small amount needed where the Extension tabs are.
You could probably get away with no infill at all.