This is not the P value you want...

Having built the QuadCopter from scratch I always knew it would need tuning. The initial few flights proved it could fly and that it responded as expected, but I had expected it to be slightly more stable given the reputation of the KK2.0 board.

After those first few flights I started looking for advice on tuning via Google. While these produced lots of opinions and advice much of it was contradictory and mildly confusing. All of it agreed that I needed to adjust the P and I values. Exactly how to adjust them and what the effects of getting it wrong would be was less clear, but as the next step was tuning, I decided I would start changing the values. (However, as I outlined in Changes the timing wasn’t ideal and I probably shouldn’t have.)

The weather finally cooperated, allowing me to fly it for the first time with all the changes in place. The results were mixed. The new cleaner layout was an improvement and the new dome gave it a more robust feeling, but the handling was noticeably worse. Was this due to the new ESC or the changed P values?

Yesterday and today saw more flights and as my experience has grown things have gotten easier, but still I felt that things weren’t quite right and that set me to thinking back to all the advice I had read around tuning the P & I values.

*Finding good guides to help with the tuning wasn’t easy and some of the videos weren’t as clear as they thought they were. Watching obviously experienced pilots perform fast manoeuvres over a large area and then declare what needs to be changed isn’t helpful 🙁 It would be great if someone could write one!
*

“The KK2.0 board requires flying.”

This was one statement I saw in many different places and led me to think that the amount of effort involved in getting the Quad airborne was normal. That said, when looking at videos of other people flying none seemed to have so much trouble so I suspected something was wrong.

Initial Values

So, what values to start with?

“For small quadcopters start with a P value of 30”

What’s a small quad? Is mine small? It’s certainly not as large as many, but is it small? As I didn’t know I decided to start assuming it was a small quad and so set the roll and pitch P value to 30, I value to 0 but left the limits at their factory defaults.

Higher Values == Better Stability?

30 was certainly too low to start and appears to have been the reason for the challenges I was experiencing.

After changing the P value to 70, the Quad lifted off smoothly and was suddenly far easier to fly! Increasing it to 80 seemed to help even more though a very small amount of oscillation started to creep in. With the I value still at 0 this was acceptable.

Next Steps

Next time I fly I’m going to try increasing the I value and also see if a higher P value gives me a little more stability.

In addition I have ordered a cable to allow me to upgrade the firmware in the KK2.0 board from the 1.2 it comes supplied with to 1.5 (or 1.6) which will hopefully also improve the stability.