Ok, I suspect I'm up against the laws of aerodynamics here, but wondered if the APM can help?Essentially I'm run big props on my quad - normal flight is perfectly ok, but it "fights" descending; wobbles, fluctuating rpms etc. For video reasons I'd like descents to be smoother.As I said - it's probably an unavoidable consequence of my config. But an improvement would be great.
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Use ESC's with "SimonK" firmware to increase the propeller responsiveness (thus allowing more aggressive P gains), and get smoother descents. Also smaller propellers/higher rpm is better for stability, but has less efficiency.
It should be noted that I "cheat" at the moment - I stick it in alt hold (actually, I use it a lot), then do "throttle stick down". It gives me a very controlled rate of descent, and the "fighting" is reduced. It works...but I don't get the descent speed I want for the shot I have in mind. I can bump up the rate, but the "resistance" increases.
Normally, I just accept it as a fundamental property of big propped quads, but now I need to get a specific shot, it becomes a (small) issue.
I could go smaller props, but that will affect my load carrying and flight time...or I could go hex or octo? Never flow them...do they descend well?
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The problem is simple but difficult to correct. In a vertical descent the aircraft is moving through the dirty air caused by the propellers.
There is no good solution other than a slow descent rate, or some horizontal movement while descending to move out of the prop wash.
Use ESC's with "SimonK" firmware to increase the propeller responsiveness (thus allowing more aggressive P gains), and get smoother descents. Also smaller propellers/higher rpm is better for stability, but has less efficiency.
It should be noted that I "cheat" at the moment - I stick it in alt hold (actually, I use it a lot), then do "throttle stick down". It gives me a very controlled rate of descent, and the "fighting" is reduced. It works...but I don't get the descent speed I want for the shot I have in mind. I can bump up the rate, but the "resistance" increases.
Normally, I just accept it as a fundamental property of big propped quads, but now I need to get a specific shot, it becomes a (small) issue.
I could go smaller props, but that will affect my load carrying and flight time...or I could go hex or octo? Never flow them...do they descend well?