2/3/2020: i just tried kingkong 48mm. they power up nicely on 3s. they're great, good control, but they are a bit fragile and vibration at high speed. they're great for small space, proximity. you should drill the mounting hole deeper, so they can sit closer to motor and that would help with benting shaft. i think they're better than Azure 2035 in terms of efficiency and control and lighter weight. both are very low pitch props.

1/10/20: i know the title says 3s, but i'm happy with 2s. i did try 3s and it's too crazy for my yard. when you try 3s with this build and you'll see what i mean.
1/10/20: weather is 30 degree which is not too cold but batteries don't like it, so the flight time is short. but i'll show the video anyway.
i like hq2020x4 cut down to 2 blades. they can turn faster than gf65mm cut down to 2inch. the thrust is about the same.
remember, when you cut down gf65mm props, they become bullnose props. meaning they're a bit harder to turn.

1/8/20: i just got hq T2x2x4 props today. i cut them down to 2 blades. and it works out great. if the weather is nice enough i will record a video.
i got frustrated with people keeping telling me, 2inch 4 blades or fat 3 blades are great.
if they're so great, why props companies don't make them or people using them for 2.5in or 3in or 4in or 5in. well, that's because they're not great.
i don't know why props companies keep making bad 2inch props. so frustrated :(

nothing special.
i just want to show how gemfan 65mm props cut down to 2in, would fly.
i just put out ideas and hope someone would pick it up and make it better.
i like this setup more with 65mm props ( no cut ). but if you have to have 2in toothpick......

frame: 2in picklepic by Alexandre Arvinte
flight controller: crazybee f4 2.1 with built in frsky ( i'm actuallly using crazybee 2.0 )
props: gemfan 65mm props cut down to 2in.
motors: Geprc 1102 9000kv
cam/vtx: mobula7 aio cam/vtx ( but it's better with runcam nano 3 and tbs nano pro32 or Eachine nano which have 5v out for convenient )
batteries; 2S 3S GnB 300mah

it's easy to cut down 65mm props.
just drill a small hole on a flat surface. stick a short toothpick in, put props on it. use foam tape and stick a nail clipper down at a distance you want. and start cutting props. be careful and consistence to cut props evenly. cut about 4mm/5mm at a time. you could cut it down to 40mm to use with 0802 motors.

and use the canopy i show in the picture and link. it would protect the camera better. it's winter and i'm being lazy to use it.
to print canopy on thingiverse is very cheap with print-a-thing service. $10 setup fee + 52 cents/each. just print like 10 of them and mess with it.

i choose gemfan 65mm props, because they're the lightest and more durable than kingkong 65mm props.
3s is faster and more efficient.
you could use foam tape to cover the board up and makes it look nicer. i'm just being lazy.

i don't know how to tune quad but i leave my pid here anyway.
2s pid is about default betaflight 4.1.1
3s pid is about P around 30 and min D about 14 with throttle clipped ( not scale ) to 70%

2/5/20: Azure 2035 props. they're a bit faster than kingkong 48mm and amp draw is a lot higher. but they feel nice in small space, proximity.
it's snowing a bit, so video doesn't look good.