I had my quad flying fairly well with 880kv motors and 10" props. I wanted to go up to the 12" props I had to get more lifting ability. When I put the 12" props on everything went crazy. Stability got bad, altitude fluctuated too easily. Altitude hold and loiter became unstable.
I am gathering there is probably an easy fix for this and rather than reinvent the wheel, I am hoping someone has been down this road before and knows the changes that I need to make :-)
I am using an APM 2.5 board with version 2.7.3 ArduCopter
Thanks
Replies
Michael, what's the pitch of your 12" props? I changed mine to 12x3.8 APC gray props and have found my 3DR 880kv quad flies pretty good with 2.73 "stock" settings. Also, I'm doing all my flying and tuning with the same payload even if I don't need the video camera and extra battery pack. My payload is a cam boom with either Sony NEX-5N or Sony CX-160 vid cam along with a second 2200mAh pack. Total 'payload' is about 550g. That's the extra 200g pack with a 350g cam.
I think the 12x3.8 props "gear down" the lift. And the payload "dampens" the flight response. I notice a difference between pitch and roll. The camera and battery are fore and aft so they deliver a higher moment of inertia in pitch. So roll is 'snappier' and pitch is somewhat slower. I could adjust this by decoupling (unlock) the pitch and roll PIDs.
So my advice is to add your payload and do your tuning with it. You didn't say, BTW, if your crazy flight was with or without payload...
Phil
you have to do the same when u change ur battery ie 3s to 4s
Hi,
You basically want to tune down anything that says rate and P. So Rate_roll_P and Rate_Pitch_P should drop considerably. They are the gains that say how fast you need to turn the motor to get the desired rate of rotation. How much more thrust do you think you have? 20%, 30%? Reduce the rate P down by that much. Same goes for throttle_rate_P
Jason