This is a stacking adapter for IKEA's very cheap but originally non-stackable NOJIG storage/organizer bins. Instead of a pillar design, which takes up a lot of space inside of the bin (and so lets you store less stuff!), it instead hangs over the corner edge and supports the corners of the bin above it.

Compatible with all sizes of NOJIG bins, and pretty fast to print (about 1 hour for 4 of them with supports, on my Sovol SV06), using very little plastic. You need 4 of them per bin, because each only supports one corner :) Definitely print with supports!

This model is very rough and messy; it's definitely alpha-grade. It works, and holds the bin above it in place pretty well, but it's a bit finicky to place correctly, and has a tendency of falling over while printing due to its tallness. I also don't like that it needs supports. Please feel free to use the design and make a better version!

Things that could use improvement:

• Using less space on the outside, making the hook flush with the bin, so that no space between bin stacks is needed.
• Improving the ‘valley’ that the bin sits in; currently it is not a perfect match for the bin corners, only an approximation. Likewise, improving tolerances so that there's less wiggling room.
• Changing the design so that supports are no longer necessary for a successful print.
• Making it less prone to falling over while printing.
• Making the design properly symmetric, instead of the current asymmetry.
• Reconstructing the inside of the hook so that it's made of clean curves, rather than the current approximation based on an inaccurate 3D model of the bins.
• Making it more difficult for the hook to slide away from the corner.