Infinite Modular Spool Rack

I looked at various types of modular racks, but I had trouble finding a design that suited my needs. So, I designed this one myself.Most designs had the following problems, which I needed to address. 1️⃣ Inefficient printing workflowTo print just a single module, I had to do three separate prints — one for the base and one for each side wall.Personally, I wanted to print multiple modules at once, ideally leaving the printer running overnight.The original design wasn’t optimized for batch printing. 2️⃣ No wall contact = less stabilityMost of the designs were fully symmetrical, the spools stuck out slightly from the back.This meant the shelf couldn’t sit flush against a wall, which felt unsafe — especially if I wanted to stack the shelves higher.I prefer to have racks that can lean slightly against the wall, both for space efficiency and stability. 3️⃣ Inefficient horizontal expansionEach module had its own left and right walls.So when expanding horizontally, walls were duplicated betwee