The story behind the build

The beginning was a GEPRC Thinking P16 HD DJI I bought.
Ok, it was nice but it suffered from deathly propwash and didn't really meet my taste.
That's why I decided to tear this thing appart and try to make it better.

Choice of components

I wanted to keep the motors and the AIO board, as well as the Vista. Everythin else was open.
I searched for a suitable frame with carbon support, because I found all these plastic frames way to wobbly.
I could not find the matching size, so I took a Beta 85X.
As a VTX-Antenna, I definitively wanted an omni, therefore i choose the lightes LHCP antenna I could find, the BETAFPV AIR.
I liked the canopy of the P16, so I kept it.

Building

I started the build with teh canopy and glued the VTX-antenna into it. My first tought was "looks like a cop car"...
After I mounted the Camera, Vista and antenna, wanted to make the canopy pluggable. A nice side-effect is, that the copter could be converted to an LOS version easily.
Just remove the canopy, add a little carbon board-safer instead and fly LOS ;)
The original P16 was configured with a softserial for the Vista (R1 via LED pad). I found out, that since V1.4 of the board there is a R1 solder pad which makes the softserial superseded.
The motors are the 8000 KV version.
After I broke one canopy, I added a carbon support for the canopys tail. This part is highly prone to break due to the VTX antenna on top.

Flight quality'

1.6x1.6x4
I run very low filters of one single D-term filter with RPM-filtering, one gyro LPF (4k PID-loop) and a Yaw LPF, pushing the master multiplier all way up to 2.0...and it's still not at the edge yet.
In the LOS version it's well powered, with the hover-point around 25 % throttle, with the FPV setup you need almost 50 % throttle to hover.
The copter flies great, agile with minimum propwash and feels almost like a 3".
But when you have to pull-out of a powerloop it's a good idea to calculate some extra meters due to the limited thrust.

2x2.3x3
These props improve the flightperformance compared to the smaller ones. They generate way more thrust but at the expense of agility.
The weight of the 2" props is app. three times that of the 1.6" props and I suppose the motors are a bit overchallenged to accelerate them fast.
But below the line it's an improvement and they also look much better.
The flight time prolonges somewhere around 30 seconds.
With the current tune, I had problems with uncontrolled movements on the yaw axis, but I thing that's a tuning issue and I have to use more filters for this setup.

Data (1.6x1.6x4)

the 2x2.3x3 props add 2 g of weight and app. 30 seconds of flight time

Weight with props: 76 g (FPV) / 49 g (LOS)
AUW with 3S: 119 g (FPV, 450 mAh) / 75 g (LOS, 300 mAh)
LOS Flight time (300 mAh): approx. 3:00 to 5:00
FPV Flight time (450 mAh): approx. 3:30 to 6:00