customizable rod elbow connector

thingiverse

I'm looking to create a bike flag attachment that features a flexible rod connector. To make this design adaptable, I need to ensure that altering the inside radius (irad) adjusts the outside radius (arad) and the height accordingly. A small cube-like structure on one side of the connector will be integrated into the lower rod to secure the outer ring in place. To assemble these two parts, a screw is necessary for their connection.