Modular angled Filament Box storage rack shelf system

I designed this modular filament box storage rack with a 15 degree tilted base so that it would be easy to slide filament in and out and to read labels when it's placed on the floor or otherwise below eye level. It's easy to use, easy to print and doesn't use excessive amounts of filament. It's designed to accept standard filament boxes up to 230mm across and deep and a variety of heights as well as having the ability to use M4 threaded rod for reinforcement or if you'd like to hang the rack from something. You will need a printer capable of printing objects up to 255mm by 220mm by 125mm.

 I've provided 2 shelf sizes, Tall shelves are designed for boxes up to 100mm tall, short shelves are designed for boxes less than 75mm tall. I've provided 3 different variants of each height of shelf

• Pattern A - This is the pattern I like the best, it has a strong geometric form without being overly repetitive and provides good strength without using too much filament to do it. The down side of this pattern is that it has some fairly large overhangs that some printers may find challenging. Diamond or other low-friction nozzles really help!
• Pattern B - This is a simple isogrid pattern, much less visually interesting but still efficient and easier to print
• Solid Side - This is the strongest and easiest to print design but at the cost of requiring dramatically more filament.

The system comprises of 

• Base unit - You'll need to print one of these to put the racks on. It's angled back 15 degrees to match with the racks and it also has room in the base to mount 2 raspberry pi's because \_(ツ)_/ why not? To use the Pi mounting points you'll need some M2.5 heat-set inserts.
• One or more rack units - Add as many as you like in any combination you like! They slot into the base and into each other. It's easiest to slot them if you drop them directly vertically onto the existing stack and get all 4 locating tabs engaged at once. Don't try to engage the tabs one at a time as the rack will get out of alignment and you'll have a tough time of it. If you want extra strength the rack can optionally accommodate long M4 threaded rods passed right through the entire stack at each support column, just drill out the holes to remove the bridges that make them printable.
• Optional Top Cap - You can just leave the rack as is but if you'd like the option to have a flat surface to put things on then you can print the Top Cap as well. If you're using the M4 support rods then the top cap has M4 nut wells so you can tighten the rods without having anything protruding at the top.

Printing Settings 

• Print using a stiff, strong filament. PLA or CF/GF reinforced filaments are recommended. More flexible materials like PETG or ABS are not recommended.
• Use a wall thickness and top/bottom layer thickness of not less than 1.2mm, extra walls will add strength more efficiently than higher infill.
• This was designed to be printed with 0.4mm or 0.6mm nozzles. Larger should work, but check your slicer's output to make sure it doesn't do anything silly
• If your slicer has an “Alternate Extra Walls” option then using it will add a lot of strength very cheaply
• It's very important the bottom layer stays flat, if it's not then assembly will be difficult. Use of brims or other adhesion aides is recommended.
• Use of fuzzy skin will make the design look more polished, but may cause challenging overhangs, especially on Pattern-A