Lots of people have been asking about PID tuning recently so I thought I would try and condense all the key info into a safe baseline tune that will start to get people in the right direction without having to copy paste a tune.
This is aimed as a starting point for x8 BF4.2 builds on 7″ or 8″ props; Siccario // Thicc. YMMV, the real value of this post is the explanation of each of the key settings
Master Multiplier: 1.2 – this turns up P I and D and makes the drone push harder to correct for stick inputs and against external forces. – This has been reduced from my initial suggestion to allow for I-term issues caused by loose cameras as suggested by Sam Sanford. Extra P & D gain is added further down this post to keep the drone following set point
PD Balance: 1.4 – this mellows out P bounce back and resists all movement by turning up the D term – this really helps make things smooth. Setting this balance too high can result in hot motors, ideally this balance is determined using blackbox logging. 1.4 is a safe bet and you can see how it feels a couple of clicks higher, checking motor temps and listening for motor trilling as you go
Stick response: 0.5 – this turns down a boost effect that pushes the drone more aggressively when the sticks are moved fast – this generally isn’t ideal for Cine stuff as you want smooth footage
I Term Relax Cutoff: 5 – this is in the right hand panel on the tuning tab. Turning this down from the default setting prevents I term accumulating when the drone is rotating faster than the threshold. This tames slow wobbles after fast flips and rolls which can happen when a larger drone is not tracking set point well
Anti Gravity Gain: 10 – this is in the right hand panel as well. Turning this up from default will reduce the amount of nose wobble you get when blipping the throttle or powering out of a dive. Settings higher than 10 might be needed but the sticks will start to feel stiff with large throttle movements
Filtering: It is possible to increase prop wash performance by reducing the amount of filtering (less filtering = bigger slider number in GUI = filter cutoff at higher frequency in hz!).
On bigger drones you really need to be using blackbox info to make adjustments before you move away from having the filter sliders at 1. You don’t fully benefit from reduced filtering unless you are increasing your PD gain at the same time.. otherwise you are sacrificing the ability to fly with damaged props without taking full advantage of the improved flight performance.
RPM Filtering is highly recommended. Once setup, put the Dynamic notch to the following settings so it can focus on the lower frequencies while RPM filtering does the higher ones:
Dynamic Notch Width Percent: 0
Dynamic Notch Q: 250
Dynamic Notch Min Hz: 90
Dynamic Notch Max Hz: 350
PD Gain: 1.3 start with your PD gain at 1.3, if you are used to flying 5″ on BF defaults it should start to feel much better, probably a little loose still. If you want to get better prop wash handling and a more dialed in feel then you can slowly increase the P and D gain, checking motor temps each time until you hear the motors trilling in the air. Then back it off a notch or two. If the motors are already trilling or getting hot at 1.3 then reduce the PD gain
For drone ops: alex AT designtuneoperate.co.uk