Does being at high altitude may affect the throttle input in rise of quad?

UKHeliBob:
The motor directions are correct for a KK2 and every other flight controller that I have seen. As to the props, when they turn is the leading edge higher than the trailing edge on each blade ?

Did you fix the problem noted in your other thread pointed out by johnwasser ?

   esc_1 = throttle - pid_output_pitch

esc_2 = throttle + pid_output_pitch
  esc_3 = throttle - pid_output_pitch
  esc_4 = throttle - pid_output_pitch




In fact, why did you start a new thread at all ?

Yeah, well about signs ,
"esc_1 = throttle - pid_output_pitch + pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 1 (front-right - CCW)
esc_2 = throttle + pid_output_pitch + pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 2 (rear-right - CW)
esc_3 = throttle + pid_output_pitch - pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 3 (rear-left - CCW)
esc_4 = throttle - pid_output_pitch - pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 4 (front-left - CW)
"
This is the original one with pids as follows: P_roll - 1.3; I_roll - 0.04; D_roll - 15; P_yaw - 4.0; I_yaw - 0.02; D_yaw - 0. same values for pitch as for roll.

with this code, my quad was bumping at start right at around 15-20% throttle. Then I recalibrated escs same issue.
So iterated lil bit changing the signs and finally got bit stable with this ones:
"esc_1 = throttle + pid_output_pitch + pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 1 (front-right - CCW)
esc_2 = throttle + pid_output_pitch + pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 2 (rear-right - CW)
esc_3 = throttle + pid_output_pitch + pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 3 (rear-left - CCW)
esc_4 = throttle + pid_output_pitch + pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 4 (front-left - CW)
"
with pids - P_roll - 2.1; I_roll - 0.04; D_roll - 0.3; P_yaw - 3.5; I_yaw - 0.02; D_yaw - 0. same values for pitch as for roll, I get stable system. like it doesn't yaw too much when I am trying to lift off even after 40-50% it remains quite stable BUT IT DOESN'T LIFT OFF AT ALL.

Also one more question is running in my mind. For a normal quad, what is usual throttle input to get lift off. I understand it is depends up on weight but on average after what throttle input will quad start to hover?