3C --- the Convertible Cop Car

By MamaJOE on Apr 25, 2022

3  128  5

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 I found out, that since V1.4 of the board there is a R1 solder pad which makes the softserial superseded.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

Photos

Part List

Frame

GEP-TKP16 Frame - GEPRC (3 builds)
Geprc.com
$9.99

Frame

Stiffener Brace of Carbon Fiber for Beta85X Frame (2 PCS)
Betafpv.com
$7.99

Frame

BetaFPV Beta85X Replacement/Spare Brushless Whoop Frame (4 builds)
Racedayquads.com
$4.99

Frame

Quadcopter multirotor stack adaptor 16x16 20x20 25x25 30.5x30.5
Armattanproductions.com
$3.00

Flight Controller

25.5x25.5mm GEPRC GEP-12A-F4 V1.4 F411 F4 Flight Controller AIO OSD BEC Current Sensor & 12A BL_S 2-4S 4In1 ESC for RC Drone FPV (2 builds)
Banggood.com
$47.80

Motors

4 x GEPRC GEP-GR1103 8000kv/10000kv motor - GEPRC (2 builds)
Geprc.com
$39.60

Propellers

GEMFAN Hurricane 2023-3 TRI BLADE PROP 4CW+4CCW (7 builds)
Pyrodrone.com
$3.19

Propellers

HQProp Micro Whoop Prop 1.6X1.6X4 40mm 1mm/1.5mm Shaft 4-blade Propeller For FPV Racing RC Drone (6 builds)
Banggood.com
$2.89

FPV Camera

Caddx Polar Nano Starlight Camera (6 builds)
Getfpv.com
$38.99

FPV Transmitter

Caddx Vista Unit for DJI Digital HD FPV (No Camera) (92 builds)
Getfpv.com
See Site

Antenna

TBS Crossfire Micro RX Antenna
Team-blacksheep.com
$3.95

Antenna

BetaFPV Air 5.8GHz Digital VTX Antenna LHCP - 2PCS (3 builds)
Pyrodrone.com
$15.99

Receiver

TBS Crossfire Nano Rx - FPV LONG RANGE DRONE RECEIVER (1331 builds)
Team-blacksheep.com
$24.95

Batteries

300mAh 3S 45C Lipo Battery S-Version (2PCS) (2 builds)
Betafpv.com
$22.99

Batteries

Tattu Batterie LiPo Akku 450mAh 3S1P 75C XT30 kaufen | FPV24.com
Fpv24.com
$11.71

Power Distribution

10 Elko Panasonic FR 470uF 16V Kondensator 105°C Low ESR same as FM 856743
Ebay.com
$2.00

Radio

RadioMaster TX16S Multi-Protocol RF Module OpenTX 2.4GHz RC Transmitter w/ V3 Hall Gimbals (82 builds)
Racedayquads.com
$199.99

Radio

21700 5000mAh Battery for TX16S
Radiomasterrc.com
See Site

Goggles

URUAV V2 3 in 1 Dust-proof Shading Sheet Protective Lens Cover for DJI Digital FPV Googles
Uruav.com
$7.55

Goggles

DJI Digital HD FPV Goggles (125 builds)
Getfpv.com
$529.00

Goggles

iFlight Crystal HD Patch 5.8GHz RP-SMA Antenna for DJI - LHCP - Choose Your Design (4 builds)
Racedayquads.com
$44.99

Goggles

2 x Double Quad RX Black Edition LHCP RP-SMA male speziell fr DJI HD FPV System (2 builds)
Antennenfreund.de
$48.82

Goggles

Replacement DJI FPV Goggles Sponge Foam Padding
Shop.iflight-rc.com
$11.99

Goggles

Ersatz Akku Li-Ion 4,4Ah (4 * 18650 Akku) + Tasche für Magicshine.eu - bikelight.eu - LED-Fire.com und andere LED-Lampen mit 7,
Amazon.de
$0.98

Hardware

5x Battery Straps V3 140x10 Whoop
N-factory.de
$4.83

Hardware

Taste Kopf M2 Titan schrauben M2x3 M2x4 M2x5 M2x6 M2x7 M2x8 M2x10 M2x12 M2x14 M2x16 M2x18 M2x20 Hex Fahrer Ti GR2 QCTI Schraube (4 builds)
De.aliexpress.com
$2.19

Misc Parts

5 PCS Super Loud 5V Active Alarm Buzzer Beeper Tracker 9*5.5mm for RC MultiRotor FPV Racing Drone (15 builds)
Banggood.com
$6.99

Misc Parts

FETtec Tiny LED Stick (2 Stück) (3 builds)
Fettec.net
$4.99

Radio Module

TBS Crossfire Micro TX V2 (43 builds)
Getfpv.com
See Site

Battery Charger

2 x Power Genius SAFE Parallel board XT30 and XT60 2S to 6S with Fuse Protection (3 builds)
Pyrodrone.com
$19.98

Battery Charger

2 x BAT-Safe LiPo Tresor sicheres Laden und Aufbewahren der Akkus
Amazon.de
$117.18

Battery Charger

2 x Amacoam 2 Stück Lipo Batterie Sicherer Beutel Feuerfeste Explosionsschutz Lipo Battery Guard Tasche Sack Gebühren Schutz Tasch
Amazon.de
$44.90

Battery Charger

ISDT D2 Mark 2 200W 12A Netzteil Lipo Akku Batterie Balance Ladegerät Entlader AC DC Dual für Rc Modelle 1-6S Li-ion Life NiCd
Amazon.de
$117.10

Soldering Iron

Tilswall Soldering Station, 65W Solder Station Welding Iron with Smart Temperature Control (392°F-896°F), Extra 5pcs Sol (2 builds)
Amazon.de
$48.82

Backpack

Skyreat Hard Carrying Case for DJI FPV V2 Goggles
Getfpv.com
$19.99

Backpack

Tarion Pro PB-01 Professional Camera Backpack
Tarion.eu
$149.99

Accessories

ETHIX Heated Deluxe Lipo Bag V2
Team-blacksheep.com
$64.95

Accessories

Kesser® Campingstuhl faltbar klappbar tragbar Angel Stuhl Camping Stuhl Faltstuhl bis 120 kg Strandstuhl Angelstuhl Klapphocker
Amazon.de
$32.03
Show stores (19)

Discussion

Sign in to comment

Mr_Stripes   Apr 25, 2022  
1

Throw some gemfan 2023 props on there to get some better flight time and punch.

Show 1 more comment
MamaJOE   Apr 26, 2022 

I tested the 2023 props an you was right ;) - see updated description

Mr_Stripes   Apr 26, 2022 

If it feels overpropped try some 2015 biblades. I have some on a quad with 0802 motors for endurance. Still has a good bit of pop.

MamaJOE   Apr 26, 2022 
1

I doesn't really feel overpropped, just not tuned. But biblades could be worth a try anyway...

Guides & Reviews

Jun 21, 2021

AirbladeUAV has done it again and this time they've brought long range to the 5" class! Based on the popular Transformer Mini, the new Transformer 5" Ultralight adopts a lot of the same design philosophies with larger props and more payload capacity. It can fly upwards of 20 minutes on a 4 cell Li-Ion battery pack and in ideal conditions it's got a range of over 4 to 5 miles. In this guide I'll walk..

Read more
Mar 04, 2021

With the release of the DJI FPV Drone cinematic FPV has become a lot more accessible, but you certainly don't want to crash a $750 drone! The QAV-CINE Freybott is a compact, lightweight cinematic FPV drone that can take a hit and keep going. It's a lot safer to fly indoors and around people. With a naked GoPro or the SMO 4k you can capture some great stabilized footage. In this guide I'll show you..

Read more