I thought I would get a little involved with this thread since my S800 / Zenmuse Z15n / WooKong-M combo just isn't flying the way it was advertised.
Lets start from the beginning, as this may also help some people.
After setting up my S800 for the first time with the WK-M, I calibrated my RX&TX (Graupner GR-16 & MX-20) and inputted the correct values (I hope correct) into the software.
Using 1x 6S 5000mah battery, and based on my center of gravity (CG) being direct center of the S800 my IMU has values of x=-7 (distance from CP to the center of the IMU) | y=0 | z=0 and my GPS has values of x:0 | y:0 | z:-17 (height of the longest GPS pole). I was using the default AP settings.
On a side note, does anyone know how exact these settings need too be? will it really ruin your flight if you are say .5 - 1cm off?
I calibrated the GPS and took it for a first test fly...flight was perfect.. flawless!
I gave it a quick few turns and back a forward motion and it was holding altitude like it was on a string.
So...super excited, I then attached the Zenmuse with my Nex7, calibrated it to a separate TX/RX (another Graupner GR-16 & MX-20) and adjusted the CG point by balancing it out with the batteries. Im running 2x 6S 5000mah LiPos on the supplied battery tray that came with the S800. Seeing as the CG point was now again in the middle, i didn't change and of the IMU or GPS position settings, nor did i change any of the AP settings.
I went out for a test fly once again, and this time the flight was much worse. the main issue was the altitude hold. It was up and down like a yo-yo sometimes raising 3-4m without my control and other times dropping as if it was loosing power. GPS seemed to be holding just fine and when i changed to full manual mode, i could 'manually' get it to hover really well. I kind of gathered that this would happen there was now a lot of extra weight. I also had to move the GPS position a few degrees to the right as mentioned in the manual, as i wasnt getting a directly straight flight when using GPS.
After some reading (this forum and others), i found that i had to change the AP gain settings.
I've since done this and although flight is much better, im still not satisfied.
The settings im using atm are: 220/220/150/180, 140/140
When using altitude hold, it seems to be holding ok with a +/- of .5m. When i switch to GPS, it starts to go up and down again.
Another strange thing that it's now doing is when i am in AH and move the s800 quickly forward by about 20m, it holds altitude as it should, but when i then bring it back toward me the same 20m, it shoots up in the air by about 3-4m & the LED flashes white twice and then back to yellow which according to the manual means 'Attitude status fair'. AHHH...so frustrating! Ive put together full MikroKopter systems in a shorter time than its taken to work this out
I have contacted DJI directly asking what the optimal settings are for the whole package combination as im not using anything but DJI systems, but no response. Im surprised they dont have a simple checkbox in the software for 'Zenmuse attached' either that or somewhere you can define the total weight of the copter and then it works the gains out accordingly.
Anyway, any suggestions on these comments would be greatly appreciated as im keen to get out and fly 'comfortably' asap!