Hard Disk Drive Rack

I really liked the idea and design of *HDD holder* by Johny555, but needed specific spacing for my HDDs. I also wanted to conserve filament and time in printing. So, I poked a few holes in the design, with this re-design using FreeCAD. To make it possibly more useful for others, I also added a couple of "generic" drive spacing versions. The versions here:

1. **HDD_Rack** - combination:
* 1 slot @ 15mm wide
* 2 slots @ 22mm wide
* 1 slot @ 36mm wide
2. **HDD_Rack-17mm** - 4 slots @17mm wide each
3. **HDD_Rack-22mm** - 4 slots @22mm wide each

**Update Note:** I have added a smaller version of this rack, designed for smaller external, portable SSD (*Solid State Drive) memory devices. See my thing "[SSD Storage Holder-Rack](https://www.thingiverse.com/thing:7267839)" for details.

Customization
-----------------
I've included the source *.FCStd* for [FreeCAD](https://www.freecadweb.org/downloads.php) (free download), in case you want to customize your own spacings for your drives. Just