I recently decided to build another Tricopter. I have chosen Emaglio's Mini Tricopter design from thingiverse (
https://www.thingiverse.com/thing:526082) and remixed a slightly changed tail and battery-cover.
My parts-list:
3x DYS BE1806 2300kv with DYS BL16 ESC
Towerpro SG90 analog Servo
Matek 5in1-Powerboard
CC3D Atom with Librepilot 16.09
CCD-Camera, Simple OSD and eachine ET-Series VTX
3S Zippy Compact 40C 1300 mAh lipo
The Mini Tricopter was nearly not flyable with default PIDs, but I managed to reduce P-values for a (nearly) stable hover in Rate-Mode. Then I used easytune in rate-mode with racer characteristics to get it flyable. If you want to try this model, start with the following PIDs:
Roll: P=057, I=229, D=08
Pitch: P=137, I=548, D=18
Yaw: P=175, I=332, D=15
I already crashed one servo in a crash, but it does not hurt that bad: The towerpro SG90 cost around 2$ a piece and the servo can easyly be changed. I'm happy with the setup, although it's a bit underpowered for a racer. FPV works fine.