Can any of you answer my question I posted about calculating thurst with a propeller. How do you do it and how many rpms are necessary per pound of thrust?

The only thing that comes to my mind would be to insert a thinner rebar type reinforcement into the brick during production.

If I have a 72 inch propeller I want to use to vertically lift something, how do I determine how many rpms I need to achieve each pound of thrust....