I am continually losing track of the various formulas and calculations required to build duration indoor models. So I have put many of these on my website to be able to find them when I need them.

Listing if the distance to the 45 deg station for various prop pitches
Calculate Propeller Pitch
Calculating the micrometer settings to cut tapers on a Harlan style stripper
Calculate the base circle diameter for wing ribs
Balsa Density Calculator that does odd size, standard thickness sheets
Balsa Density Calculator that does odd size, odd thickness sheets
Torque Meter Calculator that figures the deflection per unit of torque on any size wire
Download (225k) the balsa stiffness calculator ported to a desktop application by Fred Rash based upon a web version by Don Slusarczyk which is based upon a formula developed by Bernard Hunt.
Download (9k) the Excel EZB motorstick spread sheet by Bill Dodson. Details in INAV 105