Tehllama 'Trash' Builds - $117 5" Racer

By tehllama on Nov 14, 2020

4  112  0

Yes, it really was that cheap. Yes, it's faster than I can fully utilize. That's a good thing.

This is definite black friday budget built, with some clearance items, but can actually be copied quite affordably.
$98 is what I actually have tied up in this putting it into the air, but that did involve a frame won from a local event (but that can be easily replaced with a $18 RDQ SourceV frame)

The budget magic here is a combination of comically cheap motors, clearance stack, and proven budget FPV gear.

Motors came from Emax during a sale... When $3 motors sound too good to be true, the answer is that these just weren't popular. In 2750KV, these 2306 motors made all of the power, but do unkind things to batteries without throttle limiting... but the price was absolutely right, and this is why that price isn't just clickbait. Realistically, any cheap motor will do.
Frame is a FlightOne Leo, with some hand-me-down parts (Nytfury didn't want the 6" arms) so I cobbled it together as Hybrid build. These are actually super solid frames, and seriously underrated for stiffness, vibration management, and crash handling. Super high quality frames, and I actually would recommend FL1 frames because of the price and features... but don't get any with single standoffs on the back, that's the only way I've ever seen these frames fail inelegantly.
Canopy is a design by Truc who is an absolute wizard. If you like the look of the Arc canopies and frames, get the ArcV2, because this setup is amazing. I think I'll add on a GoPro carrier option in place of the elegant Beta-fish fin on top, because this setup has the extra power.
Stack is a clearance special - the Foxeer F722 20x20 units were on comical closeout (under $17), and the Skystars 20x20 BLHeli_S ESC's were $24, so that's what I went with. The ESC is remarkably nice for a budget unit, and running JESC the setup parties (48kHz PWM, 0.25 Startup Power, MedHigh Timing, and Demag Comp on Low). The Betaflight 4.3 tune is straightforward, and I'm running it more conservatively on DShot300 at 8k/4k Gyro/PID loops.
The included 670uF capacitor is also quite nice, ditto on the nicer XT60 connector. I wish it had built-in pit switch capability, but that's completely minor, and fixable for $3.
FPV Gear is another budget set of choices. Foxeer's Razer Micro is an excellent camera, period. I may swap it to a Predator because it flies well enough to deserve it, and the V4's are on closeout. The VTX is an AKK Race VTX, because $10 VTX does what I need it to. Finally, Foxeer Lollipop V3, again, on sale, but those are absolutely my favorite for ruggedness. Adding in a TinysLEDs RealPit VTX switch is also easy.
Props are part of how I manage the very high KV - lower pitch is the answer. Gemfan 51433, HQ 5.1x3.6x3, and DAL T5040C props all work well - this is actually where the rest of my Ethix S3 props and HQ 5.1x3.1x3 and 5.1x3.6x3 props will get used up, because that combination is amazing, I really do like HQ props on 2306 motors that make big power.
Batteries in this case are all CNHL units because price - the 4S 1500mAh 100C G+ (White Series) packs are such an insane value that I'm willing to punish them hard, but it works. This build will handle 5S packs, but with enough throttle limiting that difference becomes pretty transparent, but expect on having to make a separate PID profile if you want to tune to the limit (it's easy, but these motors are absolutely beasts).

My best builds are accidental 'trash' builds, and this maintains that tradition.

I have probably spent too much money seeing just how cheaply I can build a good racing quadcopter, but the results are consistently pretty excellent. For progressing on pace and learning how to tackle racecourses better, I will absolutely argue that a cheap build with cheap batteries have more than enough performance for 90% of pilots, and this makes more than enough speed for anybody with reasonable ambitions. The good news is that other than efficiency, this actually keeps up with the $300 builds quite easily.

Photos

Part List

Frame

FlightOne
Facebook.com
See Site

Flight Controller

Foxeer F722 V2 FPV Flight Controller (7 builds)
Fpvcycle.com
$29.99

ESCs

Skystars 35A KM35 Blheli_s ESC
Skystars-rc.com
See Site

Motors

EMAX RS2306-2750KV Brushless Motor (Black)
Hobbyking.com
$21.99

Propellers

10 Pairs Dalprop Cyclone T5046C Pro 5 Inch 5046 5x4.6x3 3-blade Propeller CW CCW for RC Drone FPV Racing (4 builds)
Banggood.com
$12.50

FPV Camera

Foxeer Razer Nano 1200TVL 4:3 NSTC CMOS FPV Camera (1.8mm) - Black (4 builds)
Tinysleds.com
$16.99

FPV Transmitter

AKK Race 25-200mW VTX w/ Pit Mode & Smart Audio - MMCX (11 builds)
Racedayquads.com
$9.99

Antenna

Foxeer Lollipop V3 5.8GHz Stubby SMA Antenna 2 Pack - Choose Your Polarization and ColorRed / RHCP (60 builds)
Racedayquads.com
$19.90

Receiver

FrSky XM+ SBUS 2.4GHz Mini Receiver (55 builds)
Pyrodrone.com
$15.99

Batteries

CNHL BLACK SERIES 1500mAh 14.8V 4S 100C Lipo Battery XT60 Plug for RC Drone FPV Racing (22 builds)
Banggood.com
$22.65

Radio

FrSky Taranis QX7 ACCESS 2.4GHz RC Transmitter - Choose Your Color (254 builds)
Racedayquads.com
$129.99

Goggles

Flysight FPV Goggles 5.8Ghz Diverity Video Goggles SPX02 40CH Wireless RC Drone Racing Goggles with HDMI in and PIP Function DJI
Amazon.com
$398.00

Misc Parts

NytFury ARC One Pod and Fin
Shop.flightone.com
$19.99

Video Receiver

ClearView 5.8 Ghz Pro Receiver - ClearView Factory Direct
Clearview-direct.com
$549.95

Radio Module

iRangeX IRX4 Plus 2.4G CC2500 NRF24L01 A7105 CYRF6936 4 IN 1 Multiprotocol STM32 TX Module With Case (5 builds)
Banggood.com
$36.99

Battery Charger

ISDT SC-608 150W 8A MINI Smart LCD Battery Balance Charger AU Warehouse (14 builds)
Banggood.com
$54.27

Soldering Iron

TS100 Portable Programmable Smart Soldering Iron (258 builds)
Racedayquads.com
$58.99

Backpack

RAID Pack II
Atstacticalgear.com
$219.99
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