Add-on Propeller Duct (Parametric)

Add-on Duct for multirotor.

This is designed to add on to an existing multirotor or fixed wing with adequate space. This will mount between motors and frame arms with the props below the motors like a pusher motor in a plane.

Proportions and parameters based on the work of Jason L. Pereira [1].
First introduced to me by capolight [2].


[1] https://drive.google.com/file/d/0BzZ213vBQVkTOHFnbUxkRVRZOGc/view
[2] https://capolight.wordpress.com/2015/01/14/quadcopter-rotor-duct/