I've built a ZMR250 based on mini APM 3.1. I'm using Multistar 2206 2150kv motors with Afro 12A ESCs and 6x2 carbon props. All the components are linked below.
The mini quad is flyable with stock PIDs and it actually loiters, RTHs, ... really well, here is a loiter example:
These are the stock PIDs, which I use:
As expected, the problems start to appear in normal flight (stabilize mode), since I suppose the stock PIDs are intended for a much bigger quad. The resulting unsmooth flight behaviour with stock PIDs can be seen in this video:
I have, so far, no experience in tuning PIDs, but I'm eager to learn in order to get smooth flight. I have tried autotune which resulted in catastrophic PIDs turning the quad unflyable - I had to rebuild the GPS tower because of the resulting crash when trying to fly with the autotune PIDs - which is why I want to learn how to tune the PIDs manually. I would really appreciate any tips on the meaning of the different PIDs and any help in getting my PIDs right for my mini quad would be really really appreciated.
Many thanks and all the best,
ps: Here is the eqipment which I used:
Mini APM 3.1: http://www.banggood.com/MiniAPM-V3_1-Flight-Controller-With-GPS-Module-p-941834.html
Motors & ESCs: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=66977&aff=1514