Table of contents
- Before you start
- Beginner's Guide
- WHOOP Section
- Go Brushless
- Tuning a quad
- Quadcopter mods
note: this guide may be a bit Whoop/Racer/FPV related, which should not discount this very good guide! I (SirDomsen) tune very similar.
After spending countless hours analyzing logs for research sake - I came to some very simple tuning conclusions that always seem to hold true. Here is my abridged and adapted guide for tuning micros. I know you didn't ask for it but it might inspire others to share something that I can learn or help someone in need.
1. Set I at a reasonable place based on known experience to start
2. Keep raising P gain until the effect of all eternal influences like wind & propwash tighten up into very high frequency oscillations. No big bumps allowed. No need for the repetitive snappy roll or pitch inputs - just go fly on a windy day and cruise around like a sunday drive & do a couple slow decents. If you can't find bumpy air - go up higher. Its there even on a calm day.
3. Raise D gain until all high frequency P oscillation is damped.
4. Go back and raise I till you see misbehavior, or the craft feels stiff - like its carrying too much momentum into turns - then lower it till that goes away and feels good to you
Pushing it further or troubleshooting: -
1. If you cant turn the bumpy ride from external influences like wind or propwash into clean crisp high frequency oscillations - then you have too much latency and P is out of sync with the motion that the gyro is measuring. Reduce filtering. You will be able to raise P higher (this happened to me with the E011)
2. If you reduce filtering too far - you will not be able to raise D gain high enough and it will be dominated by noise. This looks like a very bumpy ride for no reason
3. Find the sweet spot in filtering where you have as much P as you need to always keep the craft tight no matter what conditions you fly in and just enough clean D to keep high frequency oscillation damped.
Adjust setpoint weighting, rates, and expo to create the “feel” that you like now that it is tuned. Setpoint weighting at or very close to zero feels like a racer and increasing it slows the crafts reaction to stick inputs creating a smoother freestyle feel. The adjustment is sensitive to raise it in small increments.That feature is not widely understood.
End result - micros don't feel like micros anymore!!! I know you didn't ask for all that, but if you understand my process, maybe it will help you understand why I think an FPV camera is a better tool than a blackbox log for tuning a micro. On a larger craft - the forces that it can generate are bigger than external forces like wind so the process is different and blackbox plays a slightly different roll in the process. In short, I would not use it to tune a micro, but I might use it to help analyze a problem that I can't intuitively solve if I encounter one.
If you are flying a micro that has a bumpy ride outside - consider this procedure … it really works. I apply the same methodology to betaflight and on a typical 8.5mm craft - and this will produce P gains over 100 and D gains even higher for pitch and roll - but a locked in craft that flies like a 250 size. Those kind of coefficients may sound crazy but it really works. P gain as a starting point typically has to be increased more the lower a craft's thrust to weight ratio is. Ideally your craft should be dominated by P's influence while P is slowly corrected by I for accumulated errors, and calmed by D so it looks smooth.