Planetary calculations

Here it is how to draw a planetary gear, very useful in robotics transmissions. Using only EXCEL and OpenSCAD. The planetary could be customized to yield a proper design for your own project.

OpenSCAD has a library to draw gears, easily, however: you must be able to calculate the number of teeth related to the wanted pitch.

I tried to build a library to ease this process, instead I found excel useful to make the calculations.