Hello All!
I finished a build of 250 quad recently:
![[Image: assembled-for-first-flight.jpg]](https://dl.dropboxusercontent.com/u/54741704//Other/copter/el%20el/assembled-for-first-flight.jpg)
After some doings with the settings and radio and so on I finally got it to fly ok in autolevel. But in rate mode there is slight angle drift on pitch (it increases incline to back).
The trick here is that quad actually not balanced – it’s center of gravity is ~2.5 cm to back from the center. I know that it possibly will fly better if balanced, but I just want to understand where this angle drift comes from so I experiment with unbalanced quad.
As far as I understand, the “rate” mode is something like “angle lock” mode – sticks control the speed of angle change, and when sticks are not touched it should maintain the set angle. But it does not.
What confuses me a lot is that the speed of drift is different over time. At the flight start (battery full) – the quad maintains angle ok, but as closer it gets to empy battery, the more it changes angle by itself (up to about a degree per sec or even more).
Why it can behave like that? Can you, please, recommend me a direction to continue investigation? Again, I suppose I can fix it by balancing quad itself, but I want to understand this behavior as I expect it to keep angle.
I finished a build of 250 quad recently:
After some doings with the settings and radio and so on I finally got it to fly ok in autolevel. But in rate mode there is slight angle drift on pitch (it increases incline to back).
The trick here is that quad actually not balanced – it’s center of gravity is ~2.5 cm to back from the center. I know that it possibly will fly better if balanced, but I just want to understand where this angle drift comes from so I experiment with unbalanced quad.
As far as I understand, the “rate” mode is something like “angle lock” mode – sticks control the speed of angle change, and when sticks are not touched it should maintain the set angle. But it does not.
What confuses me a lot is that the speed of drift is different over time. At the flight start (battery full) – the quad maintains angle ok, but as closer it gets to empy battery, the more it changes angle by itself (up to about a degree per sec or even more).
Why it can behave like that? Can you, please, recommend me a direction to continue investigation? Again, I suppose I can fix it by balancing quad itself, but I want to understand this behavior as I expect it to keep angle.
![[-]](https://intofpv.com/images/collapse.png)
