uSmile 100mm Ultralight 2.5"

By Ciotti on Apr 01, 2018

7  610  0

This is one of my earlier ultralight 2.5" builds which at 53 grams dry floated like no other 2.5" micro I've ever seen.
The sacrifice for that float was smaller motors/less horsepower, these old school Racerstar 1103 8,000's are only 3.3 gram each by sacrificing the screw holes since you really don't need them at this power level. Because of this I used a Kyocera 1.47mm drill bit to run through props when replacing them to make sure the hole isn't too tight which could push the motor shaft down out of the bottom of the bell. If the prop is too loose on the shaft, all you needed to do is put a tiny bit of superglue on the tip of a pin/clothes pin/paperclip, smear it around inside the hole of the prop, let it dry, and then run the drill bit through it by hand again to make sure it's not too tight. The residue of the dried superglue is rough and allows the prop to bite against the motor shaft.
The FC has blackbox which really helps with tuning, but as you can see from the video I have it locked in and ready to go.

The batteries I ran on this rig were...
15.2 gram 2s 300mAh
17.5 gram Nanotech 2s 300mAh
20 gram Sky Hobbie 2s 350mAh
22.2 gram Mad Dog 2s 350mAh

uSmile 100mm Carbon frame
Omnibus F4 FC w/blackbox
FrSky Xm Receiver
Babyhawk 200mW camera
Old school Racerstar 3.3 gram 1103 8,000kv motors
Racerstar 6A 4in1 ESC


Part List


Usmile 100mm Half Carbon Fiber Quadcopter Frame Kit for 1104 Brushless Motor Indoor FPV racing - Urban Drone Store

Flight Controller

Micro 20x20mm Betaflight Omnibus STM32F4 F4 Flight Controller Built-in BEC OSD for RC FPV Racing Drone (8 builds)


BangBang Racerstar 20x20mm Mini RS6Ax4 6A 1-2S Blheli_S BB2 4 In 1 ESC with 5V BEC Support 16.5 Dshot600


Crazepony 4pcs BR1103 10000KV Brushless Motors for 50 80 100 Multirotor Quadcopter Drone Red (6 builds)
See Site


usmile 10 Pairs of 2435 60mm Propeller Props for Brushless Micro Carbon Fiber Quadcopter frame 120mm Quad Frame (Red)


Hubsan X4 H107L H107C H107D Propeller Blades Props 20pcs Propellers (Blue) by Funny Utopic (2 builds)


AFUNTA Propeller Blades Compatible Hubsan X4 H107 H107D H107C H107L Quadcopter, 4 Sets (16pcs) Transparent Props Rotor for Helic

FPV Camera

Emax Babyhawk 87mm replacement VTX FPV Camera 25-200MW


FrSky Ultra Light FrSky XM Receiver up to 16CH for X9D PLUS Q X7 X9E (4 builds)


5 x Turnigy nano-tech 300mah 2S 45~90C Lipo Pack (8 builds)


FrSky Taranis Q X7 2.4GHz 16CH Transmitter (White) (263 builds)


Fat Shark Dominator HD3 Core FPV Goggles (87 builds)

Video Receiver

ImmersionRC rapidFIRE w/ Analog PLUS Goggle Receiver Module (179 builds)

Radio Module

TBS Crossfire TX LITE (6 builds)
Show stores (5)


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