Does anyone know the diameter and pitch on the self tightening props? I have a few that are tough to thread on and whnt to purchase bottoming taps left and right hand to fine tune the threads. Seems any props other than original DJI have this problem. I also saw that the other problem with aftermarket props is that the large opening before the threads in the prop has to be cleaned up with a 5/16 drill bit, I did this with the bit in visegrip pliars so I had control and turned the prop slowly by hand. Now the shoulder under the threads on the motor shaft do not get galled by the aluminum inside the first shoulder on the prop. Thanks!