Big Einsy Case for Bear Upgrade

This is a remix of [Boogie's Big Einsy Case](https://www.prusaprinters.org/prints/31558-big-einsy-case) on prusaprinters.org for the Bear Upgrade. Additional attributions on the prusaprinters.org listing: [Big Einsy Case for Bear Upgrade](https://www.prusaprinters.org/prints/72191-big-einsy-case-for-bear-upgrade).


Notable changes

* Geometry added to mate with the Bear Upgrade V-Slot Extrusions
◦ Use either drop-in or standard T-Nuts
◦ Use either M5-10 socket head or M5-8 flat head screws
◦ Temporary M3-12 screw (orange)  added to aid in sliding T-Nut alignment.
• Case is 3mm wider to accommodate M5 socket head screws
• Vent pattern inspired by Prusament filament spools.
• Extruder cable clamp diameter reduced to 13mm and tie wrap securing added.
• The square and hex nut cavities were resized for better retention.

Printing

* Layer height: 0.3mm Draft
* Supports: “Support on build plate only” with painted support blocking. See .3mf file for details.
* Filam