Huge vibration of props until the copter is takeoff

[JackJavan]

@asw2000 something that worked for me was reducing mot_thst_expo and then setting Mot_spin_min slightly higher and then recalibrate esc from within mission planner. My take off vibration was gone. But I should mention in my case I set mot_thst_expo at 0.
https://ardupilot.org/copter/docs/motor-thrust-scaling.html
Please check more details regarding thrust expo and set it according your esc and motor configuration. Since its in-house motor and esc you should have your thrust curve and details and you can have easier time than me.

Using "measured" MOT_THST_EXPO: What improvement can one expect?

Hey let’s assume one has measured the motor thrust curve and thus can determine a more accurate value for MOT_THST_EXPO, than the default of 0.65. Theoretically this should improve control and thus the copter behavior. What I’d like to understand better, since I lack the experience/knowledge: How much of a positive effect can one expect in practice? If there is any significant effect, how could one actually validate/demonstrate the positive effect, in some objective manner? Thx, Olli

Checkout this discussion too.