Last week I studied Loco system, which is a posibile solution to estimate the absolute position of crazyflie. The system has two parts: a Loco deck add on crazyflie and 4 Loco anchors at ground. The system as whole works as a mini GPS system and calculate crazyflie's 3D position. For the simulator I am working on, in order to model the attitude dynamics of the system, we need to know the MOI of propeller. There are may ways to estimate This MOI. One is use a load cell, which is not accurate. Physical pendulum are commonly used to measure an object's MOI, but a small object has relatively large air resistance, so it is less accuriate to be used for a small propeller. After takled to Wenzhong, I knew that a propeller CAD model may be more useful for MOI estimation. I searched online and found out there are may CAD projects for propellers and I think that would be good references.