Whirlygig 3" 4S Tricopter V1

By 1Smug_Bastard on Jun 04, 2019

11  353  25

Remix of the original Whirlygig 2" to reduce flex and improve flight performance. Copter arms are teardrop shaped to allow for better airflow.

Estimated Spec's calculated using https://www.xframe.tech/
Thrust to Weight Ratio: 6.25
Hover Flight Time: 21.1 minutes
Race Time: 6 minutes with max speed of 72 Mph.
Total Weight: 131 grams (Camera and battery)

Thanks to the removal of the Servo-holder, the entire print is done inverted and thus print supports are no longer needed!
From this point on, a single Nylon M2-screw is used thru the frame to support the Servo via its tab.
(as needed a Zip-Tie can still be used to provide additional support)

Notes:

  • Weight with battery 131 grams with 6.25:1 TWR. (hovers at 16% throttle)
  • Emax 1106-4500kv motors run without a Throttle Multiplier.
  • Frame Printed from Nylon / Carbon fiber mix with 0.4 mm print head.
  • 2.5 mm wide Zip-ties used.
  • For those interested in acquiring the frame, https://www.printhub.store/shop​ .
  • Updated the build with the new stiffer frame.

Edit: 7-5-2019, did the first flight (LOS) and cant get the throttle higher then 30-40% without the copter turning into a missile. Maybe more manageable in FPV flight but I have yet to try this. Tail wag is non existent but Roll / Pitch D-Term sounds a bit high due to slight warble sound observed. Was able to have a bit of fun with it Looping and Rolling like a champ!

Edit: 7-4-2019, was able to Auto-tune yesterday and perform a quick test flight today. Yaw is ungodly powerful when the throttle is punched. Will have to incrementally detune this to get something that plays nice.

Photos

Part List

Frame

Prinhub 3D Printing Services
Printhub.store
See Site

Flight Controller

Matek F405-MINI Flight Controller w/ F405, 32k Gyro, BFOSD, 32M Flash (3 builds)
Getfpv.com
$31.99

ESCs

Aikon AK32PIN 4-in-1 25A 6S 20x20
Copterfarm.de
$54.89

Motors

3 x EMAX RS1106 II 4500Kv Micro Motor (23 builds)
Racedayquads.com
$38.97

Propellers

EMAX Avan Mini 3x2.4x3 Tri-Blade 3" Prop 12 Pack - Choose Your ColorRed (13 builds)
Racedayquads.com
$4.49

FPV Camera

Crazepony MICRO FPV Quad
Crazepony.com
See Site

Receiver

FrSky R-XSR SBUS 2.4GHz Micro ReceiverDefault Title (748 builds)
Racedayquads.com
$19.99

Batteries

Tattu 14.8V 4S 450mAh 75C LiPo Micro Battery Battery - XT30 (8 builds)
Racedayquads.com
$10.11

Power Distribution

Mini-360 DC-DC Buck converter (3 builds)
Solarbotics.com
$3.65

Hardware

BMS-101HV (Coreless)
Blue-bird-model.com
See Site
Show stores (7)

Discussion

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Laetschi   Jul 05, 2019  

Looks crazy, how did you get the Servo to work? did you Just Connect the Signal from the Servo to the free MotorSignal-pad?

1Smug_Bastard   Jul 05, 2019 

I'm using pad "1" for the Servo with a PWM rate of 330Hz.. (Digital Servo running on 7.5V) From there just wire up the motors as you would any Quad.

Granted, this can also be done using Betaflight but from my own experiances with Beta, its not too Tri friendly. Specifically, tuning is a major pain, especially with a custom rig like this. PID's have to be kept low and worked upwards as even the slightest increase cause instability. You can surmise that this takes a long time and thus is not for those new to tuning.

IcarusIX   Jun 20, 2019  

This is awesome, design is really slick. how has it held up?

Show 14 more comments
1Smug_Bastard   Jun 23, 2019 

Yeah... far as i know of what currently have is Digital.

Pros: Faster, less jitter, higher PWM rates , often better torque.
Con's: A bit more expensive

Best to run the Servo at the highest voltage and PWM rate it can handle. This allows the response, torque and stall current to be much improved. I try to run at 7 volts / 330 hz if the hardware permits.

1Smug_Bastard   Jun 23, 2019 

BLUEBIRD BMS-101HV

Digital Controller 12-Bits ( 4096 Steps ) / Frequency:333Hz / Neutral:1520us, 6.0V ~ 8.5V input.

1Smug_Bastard   Jul 03, 2019 

New frame is very good. Can hardly bend it, yet its so thin.

Jodie Froster   Jun 04, 2019  

Sick man, profiling the arms like that is right on time!

1Smug_Bastard   Jun 04, 2019 

Thus far its much stiffer than the earlier 2” whirlygig and has tons of power. So much so, i have to scale the motor back by half. Yet still the TWR is 4:1 !

Only issue i have this far is that the DYS 4-in-1 F18 ESC is garbage. Dam thing has had issues from the very first moment. Everything from it not keeping Sync with any protocal other than dShot-300 to motors that sputter in flight. Will replace with an Aikon unit tomorrow. Motors ohm out fine so i dont really have any other option but to toss the DYS.

Edit: Powered up the Aikon ESC alone to have it short out instantly! (WTF)

Jodie Froster   Jun 08, 2019 

Brutal.

1Smug_Bastard   Jul 03, 2019 

Ok got the ESC issues sorted out and installed the new frame. This frame is reenforced with Carbon-Fiber inside the Nylon. While this is a little more expensive to have printed, its basicly indestructable, short of jumping up and down on it.

1Smug_Bastard   Jun 23, 2019  

Just added the motors and Servo to the newly printed frame. It's at least twice as stiff as the previous frame, while gaining maybe a gram in weight.

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