After a long session of working on the model, I have finally finished it. This is my first project using Fusion 360 so I may have made some mistakes and the model quality could not be perfect but I am happy with it.

I also made the connections between pieces 0.2 mm smaller on every side. That's because the laser cutter erases from 0.1 to 0.2 mm and that way I can stick the pieces together without any glue.

Here are some renders of the tank: