I’m useless at flying mini quads. Project “Get good at flying mini quads” is my way of try to improve my skills whilst helping others to learn along the way.
Part 4 – Tuning
Good tuning is the difference between a good pilot and a great pilot but it is also one of the hardest skills to learn in the sport of drone racing. In this part of the project I tried to get the best possible tune I could out of my R220 Evo FPV Racing Drone. The odds were stacked against me (as you’ll see) but I did learn a lot along the way.
Below the video you’ll find a list of all the resources I used for this part of the project…
- BorisB Betaflight – alternative cleanflight firmware
- Stopped Clock: The Chore of Tuning PIDs – Jimmac’s excellent PID tuning tutorial
- F1FPV: Full PID Tuning Cleanflight in FPV – A nice tuning video by Shelby Voll
- The Perfect Multirotor Tune – Another clear video from IBCrazy
Tuning your FPV Racing Drone (can be tricky)…
So as I said in the video, this article isn’t supposed to be a tutorial in tuning. I’m just not good enough at it for that! There are however plenty of others who do have the skills and knowledge and I’ve linked to some of them above. These are the rules I followed:
- You can’t tune with self-levelling turned on. Some experience and comfort with rate mode is essential
- Tune the P first, then the I and finally the D. You can normally do the majority of roll and pitch P/I tuning together
- Tuning the yaw is just as important for a truly “locked in” feeling
One of the most useful tools I discovered during this article was the use of in-flight adjustments in CleanFlight. Once connected to the CF GUI, clicking on the “Adjustments” tab gives a whole host of tuning options that can be assigned to switches on your transmitter. The Taranis and CPPM comes into their own here as I could easily assign two 3-position switches to Aux1 and Aux2 (channels 5 and 6). This allowed me to assign 3 parameters at a time (e.g. Roll & Pitch P/I/D) to one switch and Increase-stop-Decrease to the other. What you have to remember is after landing and disarming move the left stick to bottom left and right stick to bottom right to save your settings (mode 2).
Tips & Tricks I learned…
- Start with the stock settings as these are often quite close to a good tune.
- Push the P up until you see fast vibrations then decrease until they stop. This way you’ll know the upper limit. Be sure to test at high throttle settings as well – setting P at 30% throttle is no good.
- Take time on the I to get it right. You can mask bad I settings with high D but it won’t be as locked in. Make sure you test your I whilst descending AND moving forwards. If you come straight down you will be in your own propwash and that is always going to be a bumpy ride!
- D will be a lot higher than you think it should be. If you go too high the ride will feel a bit too robotic so be sure to play around with the numbers until it is locked in but feels smooth and responsive.
- Tune the yaw in line of sight or adjust the camera to zero tilt. Don’t do what I did and try tuning with a 20 degree tilt!
- Make sure your quad is balanced but tune with the same setup you intend to fly. It’s no good using a smaller battery and removing the GoPro if that isn’t what you intend to use every day.
- In BetaFlight the “Rate” settings don’t effect the tune so you can play with them later to get a faster flip and roll rate.
A last word about YAW
I’m still not convinced about my yaw tuning. I need to spend some more time tweaking it as not only was camera angle an issue but the yaw footage in the video was showing a definite overshoot and struggle to stabilise. In Shelby Voll’s video he advises dropping the P gain on yaw quite a bit as it is very high in the stock settings. I’m not sure this is the right thing to do but until I try it all out I’ll never know.
Another theory I read is that yaw response has a lot to do with prop selection. In this video I was tuning with 5030 triblades. These are very light and low pitched so the theory might be true. I shall try some heavier 5040 bullnose and see what happens.
I’m not sure I ticked all the boxes with this one but it has taken so long and so many botched attempts to cover the subject that I eventually had to run with it.
I’m happy with my roll and pitch tuning. The quad feels nicely locked in and flies well. The BorisB BetaFlight is an excellent firmware and the stock settings for PID1 are a great starting point. In-flight adjustments are definitely the way to go as they saved me a huge amount of time going back and forth to the computer to make changes.
Anyway, I hope this helped a little bit. I’ll try to do a follow up soon on the yaw tuning and how the numbers ended up. This is what I have at the moment…
RC Rate is set to 1.00.
Note: I haven’t ignored setting looptime! In BetaFlight, looptime is no longer a parameter that can be manually set. The software decides it for you. On my setup it seems to have settled for a looptime of around 1000.
- R220 Evo carbon racing frame
- Quanum 2204/2300 motors
- Afro 20A Race Spec ESCs (running BLHeli 13.1 and damped light)
- Naze32 Acro Rev5 flight controller – BorisB Betaflight firmware (CleanFlight)
- Gemfan 5030 triblade props
- Zippy Compact 1500mah 3S 40C LiPo
- HobbyKing FT952 200mw VTx with IRC Spironet antenna
- Turnigy IC-120SHS CCD camera
- FRSky D4R-II Rx with CCPM and Telemetry via Naze Soft Serial port
- Mobius C Lens HD camera