ISB extrusion interlocking connector

I needed in my project 40x80 extrusion, but I only had 2040 ISB type profiles laying around - so I made a connector how they can be combined as one solid piece.

I included the fusion files for you to make your own - i tried 10mm but ended up using 15 mm tall pieces, the longer the bit is the more difficult it is to slide in.

Later I will make my 40x80 as v-slot by https://www.thingiverse.com/thing:4189668