Customizable Parametric Book Holder

I started this because I wanted a book holder that fit my shelf, not the other way around. 

Couldn't find anything customizable enough, so I built this parametric one instead, adjustable in every dimension that matters.

What you can change:

• Total width and number of slots (overall size, not just a fixed model)
• Height of each divider, independent from the others
• Central cutout on the dividers (size, with an automatic reinforcement pillar above a certain width)
• Weight-relief windows in the base
• Reinforcement curve at the base of each divider (flare left, flare right): turn it off on the side(s) if you plan to connect multiple pieces (printing separate modules to join side by side instead of one standalone block)

A few print profiles for standard sizes are included if you want to print right away without opening the Customizer. 

But the model is built to be adapted, so change the parameters before printing when you can.

Tested for bridging and internal span strength: the default values are calibrated, not arbitrary.