Changing ATC_ACCEL_P_MAX/ATC_ACCEL_R_MAX/ATC_ACCEL_Y_MAX on large sized heli

I am trying to fine tune my 800 size heli ( using 3.4.6). I noticed that the tail was very sensitive. So I changed the param ATC_ACCEL_Y_MAX from 270 to 140. This helps a lot and the tail is much more easier to handle. I think it makes sense since having the default rate 270 degree/sec ( ¾ of turn) is too much for a 800 size heli. It may be OK for 450 size heli though.

After this change, I was wondering if someone has tried changing ATC_ACCEL_P_MAX/ATC_ACCEL_R_MAX to value smaller that the default value (1100) on a big heli. The same logic might apply to the roll and pitch as well.

My standard settings for my large helicopters on pitch and roll are around 52000 on the 600’s, 36000 on the 900.

Please keep in mind those params are not the rate. They are for angular acceleration limit and affect the autopilot as well as you flying manually. You can set RC_FEEL if it’s just an issue with manual flight modes.

Hi Chris,
I tried ATC_ACCEL_P_MAX/ATC_ACCEL_R_MAX set to 40000 and it works great for me. I was curious what do you use ATC_ACCEL_Y_MAX for bigger heli. I am using 13000 and it seems to be working OK for me.

Also for bigger heli which can move much faster what do you use for WPNAV_LOIT_SPEED. I still have the default value of 500 but I feel increasing it to perhaps 1000 will work great.

That sounds perfectly reasonable for a 800 size that you want to handle more like a UAV/scale model instead of 3D snappiness.

i actually set mine to 300 (3 m/s). I do not use Loiter for a manually flown flight mode. I only use it for stationary hovering and/or limited moving where I want the autopilot to fly the heli so I can concentrate on other things. And when I move it I want it to move gentle and slow. I switch to Alt Hold if I want normal speeds and handling with altitude control, as Loiter is too “jerky” and unnatural for my tastes, for flying the heli around.

That being said, there’s nothing wrong with 1000 (10 m/s) if you use Loiter for flying around. As long as you keep in mind the limitations of Loiter flight mode as a pilot-controlled mode.