Li'l Grim Reaper SR --- 4S, 3" Build - Naked Vista, super-low filters *flight video*

By MamaJOE on Jan 11, 2023

11  433  5

The story behind the build

This is the evolution of my Li'l Grim Reaper Build.
Long story short, watch how it flies:

After I crashed this little guy and had to take it appart anyway, I tought of make some improvements regarding the flight performance.
The major change is the frame, which is now doubled to make it super stiff and allows me to use only minimal filtering in Betaflight.
To compensate the surplus weight, I decided to strip the vistas heatsinks.

Choice of components

The components already existed and I just modified the construction of the stack and changed some small parts.
For the camera I upgraded to a Nebula Pro Nano, which seems to be the best choice due to it's low weight an the 120 fps.


I had some headache about the durability of a naked vista, so I added two tiny headsinks on top of the upper board, which doesn't get so much airflow due to the canopy. Furthermore I let a big spacing between the two board. Till now it works without any problems, even on full-power.
To use the potential of the stiffened frame, I added a JST SH socket, providing a UART, to connect a data logger (JHEMCU F4-Openlager) for tuning flights.
I added a second JST SH connector for the RX, because I have a very weird issue in conjunction with this AIO board: as long as the RX is connected, I cant't flash the board. Therefore it's a big advantage just to unplug the RX than desolder it.
The Micro USB connector of the AIO board ripped off short before, so I took the chance to place it tuning-friendly :)

Flight quality

This tiny guy really flies super responsive with a good powerlevel. It's fun to throw it around and you have to push hard to get it into prop-wash.
The 550 mAh battery offers a better weight-to-power-ratio, while the 650 mAh battery offers great flight time.
But form your own opinion how this quad flies and watch this: short flight


Weight with props: 104 g
AUW with 4S 550 mAh: 165 g
AUW with 4S 650 mAh: 181 g
Flight time (550 mAh): approx. 3:30 to 7:00
Flight time (650 mAh): approx. 4:00 to 8:00


Part List


Quadcopter multirotor stack adaptor 16x16 20x20 25x25 30.5x30.5


GEP-SP SKIP 3inch Frame - GEPRC (2 builds)


HGLRC Petrel 120X 3 Inches Toothpick FPV Frame Kit (5 builds)

Flight Controller

HGLRC Zeus25 AIO 3-6S F722 Flight Controller 25A BL32 4in1 ESC (2 builds)


4 x iFlight Xing2 1404 3800KV Motor (18 builds)


HQProp Durable Prop T3X2.5X3 Grau T3X2.5X3GR-PC (4 Stk.) (2 builds)
See Site

FPV Camera

Caddx Nebula Pro Nano Digital Camera (16 builds)
See Site

FPV Transmitter

Vista Unit Module (3 builds)
See Site


TrueRC SINGULARITY 5.8 U.FL LHCP (8 builds)


RadioMaster RP2 ELRS 2.4GHz Nano Receiver w/ Ceramic Antenna (11 builds)


See Site


Tattu R-Line 650mAh 4S 95C Lipo XT30 (11 builds)

Power Distribution

2 x Panasonic 25V 330μF LOW ESR Elektrolytkondensator Capacitor Filter FPV Drone
See Site


Boxer EdgeTX Rotor Riot Edition Radio Controller - ELRS (4 builds)


21700 5000mAh Battery for TX16S
See Site


DJI Goggles 2 - Ultra Low Latency 1080p/100FPS 4K/60FPS Digital HD FPV (22 builds)

Misc Parts

Accueil (7 builds)
See Site

Misc Parts

OpenLager (3 builds)

Battery Charger

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

Battery Charger

3 x BAT-Safe LiPo Tresor sicheres Laden und Aufbewahren der Akkus
See Site

Battery Charger

ISDT PC-4860 Lipo Ladegerät Parallel Ladestation Unterstützung 4 Packs von 1-8S XT60 RC LiPo Akku
See Site

Battery Charger

HGLRC Thor Lipo Battery Balance Charger Board Pro 40A XT60 XT30 Plug 2-6S Integrated with Lipo Discharger for IMAX B6 ISDT Q6 Na (2 builds)

Battery Charger

Q6 Nano Lipo Ladegerät, DC 200W Smart tragbares digitales Ladegerät fü

Battery Charger

2 x Amacoam 2 Stück Lipo Batterie Sicherer Beutel Feuerfeste Explosionsschutz Lipo Battery Guard Tasche Sack Gebühren Schutz Tasch
See Site

Battery Charger

K2 Air Bluetooth Fernbedienung LIPO Ladegerät, AC/DC 200W/500WX2 20A S

Soldering Iron

Tilswall Soldering Station, 65W Solder Station Welding Iron with Smart Temperature Control (392°F-896°F), Extra 5pcs Sol (2 builds)
See Site


Tarion Pro PB-01 Professional Camera Backpack


ETHIX Heated Deluxe Lipo Bag V2


Kesser® Campingstuhl faltbar klappbar tragbar Angel Stuhl Camping Stuhl Faltstuhl bis 120 kg Strandstuhl Angelstuhl Klapphocker
See Site


LINGHUANG Avata Tragbar Aufbewahrungstasche für DJI Avata für DJI Goggles 2 für Motion Controller, Tragetasche Schutzhülle f
See Site


Onseuk Kompatibel mit DJI AVATA Goggles 2 Foam Pad Sponge Comfortable Eye Mask Drone Goggles Zubehör (Grau+Schutzhülle)
See Site

Misc Supplies

Bier – Wikipedia
See Site
Show stores (18)


Sign in to comment

Vincent12FPV   Jun 11, 2023  

Hi, It is a nice build you have here ! What did you use above your soldering that black paste ? and how did you applied it ?
By the why I like that you added Bier in the supplies list ! :D loved it

MamaJOE   Jun 11, 2023 

Thank you!
Yes, beer is an essential operating least for Germans 😄
The black paste is Liquid Tape, a liquid rubber that keeps cables from breaking and also insulates them electrically. It is simply applied with the tip of a screwdriver.

ClimbMit   Jan 20, 2023  

Nice and clean! What did you use to hold the frames together? I was thinking of using JB Weld to double up on my Crux35.

MamaJOE   Jan 21, 2023 

Thanks for your comment! I just used longer screws and fixed the two frames at the motor mounts and the stack mount. Additional, I put some magic damping grease between the frames. It's so sticky that the frames are bond together and it helps to reduce vibration!

ClimbMit   Feb 07, 2023 

I never thought about something greasy and sticky that would help reduce vibration. I think i get it though? I imagine that the grease forms a natural suction as well a long with being sticky. I applied JB Weld on two Crux35 bottom plates. so far so good. That perfect power to weight ratio seems a little off now. Still flies great! I know very little about pid tuning. Just using the presets in Betaflight 4.3. So much to learn in this hobby!

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