Nano Whirlygig Tricopter 3"

During Covid-19 my son and I enjoyed designing and building various Tricopters. The Whirlygig was our attempt at making the smallest Tricopter possible for outdoor use. All up weight being just over 54 Grams and acrobatic flight time of just under 4 minutes.

Video

Printing

Will print just fine with PLA, PET or Nylon. Suggest 0.2 layering and a slightly higher than normal extrusion temps for better layer adhesion.

Specs / Hardware 

• 2S 300 mAh LiPo
• BetaFPV 1103-11000KV motors
• CrazyPony AIO Nano Camera / VTX combo
• BetaFPV F4 1-2S AIO Brushless “Flight Controller” with SPI FrSky receiver
• 3025 propellers
• BlueBird BMS-101HV Servo 
• Whirlygig Toothpick frame (see downloads)

*** The instructions below assumes that the builder has some experience with electronics, quads, and the software related to RC aircraft. ***

Setup

• Wire both the Servo and the Flight controller directly to the 2S Battery. (Servos use 5-7 VDC)
• Connect the Receiver and the camera to their respective pads on the flight controller.
• Connect the servos control lead to the Flight Controller's LED pad. Then remap the LED pad so the controller knows where the Yaw is.
• Within Betaflight, choose the model profile for “Tricopter”.
• Assuming your Flight Controllers ESC's can support it, enable motor-filtering, as doing so will greatly improve flight stability.
• Set the servo refresh rate to 300hz.
• Make sure that the servo is at its mechanical zero before attaching the tail mechanism. Use the small screw (provided with your servo) to attach the tail mechanism to the servo.
• Within Betaflight the servos PWM “zero” (pulse width modulation) is normally 1500. When the servo has been properly mechanically zeroed, you should see the servo snap to zero as soon as power is applied. (Not armed)
• Mount and wire up your motors. 
• Follow the propeller diagram within Betaflight for the proper orientation and rotation.

*** Warning do NOT install your props until your sure that the copter is working correctly. ***

Notes

• The tail mechanism will need a small amount of printing support around its mounting point to the Servo and maybe in the screw hole as well…
• Included in the images are the basic PID settings for the Whirlygig. Be aware that Servos do NOT like Yaw D-gain, so keep it at zero.
• When power is first applied, should the tail start to wag uncontrollably, its likely that the P or I gains are too high. (Powered up but not armed)
• If a motor is spinning the wrong way, this can be swapped either by Betaflight or with the ESC firmware updater. Should this prove difficult, you can always swap around two of the three wires, to reverse the motors direction.
• Some of the hardware I've listed above may not be available. Thus as required, all of the hardware can be substituted easily, so long as the physical size is correct.