Rigidity and theory

Seems like my .6mm thick stainless steel pipe is less than required. Or the build is too big for the pipe.

Anyway, here is a model to calculate the max. bending, max middle assembly weight or to get the dimensions you need for a certain build.

It was a 5 minute job so if anyone has any questions (or spots a mistake), please ask.

Didn’t find a similar thing posted. If it was, please take my thread down.
Btw, the model is incomplete (just a sketch)…