3D printing optimised 3-way 2020 corner joint

A 3-way 2020 extrusion joint inspired by Slant 3D's video on printed joints. This does not fully wrap around the extrusions to allow panels to be mounted on the outside which means it is not as strong as the design he showcased in his video but still offers homogenous strength in all 3 dimensions. This also reduces the number of joints needed for a cube to just 8.

3 walls at 15% cubic infill is plenty rigid.

Tolerances are tight and make sure you compensate for elephant foot and have sufficient cooling for maximum print accuracy.