The heart of your indoor duration model is undoubtedly the propeller - learn how to design and build them here.

This is a link to a spreadsheet that will help you draw up a Larrabee style propeller shape - click here.

Here's a spreadsheet that will calculate either Pitch or Blade Angles for you at different radii along your prop blade.

Bob Bailey has provided this Spreadsheet and User Notes which will enable you to automatically generate the measurements you need to draw up a complete Prop Block using the minimum of materials.

Finally this is an article by Brett Sanborn - with permission of INAV - on constructing Carbon Fibre prop outlines.

F1L and F1R props gd