ng2423iv2

Introduction:

The third iteration of this wing (now with a real airfoil). My guess is that this will give significantly more lift than previous KF airfoils and will allow much more efficient flights.

Components:

• Sunnysky 2204 2300kv motor

• Hobbyking 18a 2-3s esc with 2A BEC

• Dollar tree Foam board & pipe insulation

• D8 Sbus/pwm receiver Frsky xm+

• Noxe F4 flight controller (flywoo version)

• Beitian 180 GPS

• Lumenier CP-520 camera

• 2x SG90 servos

• HappyModel Whoop vtx 25/100/200 VTX FX799T 200mw vtx

• Buzzer

Conclusion:

192g dry.

Maidened on the same day as completion. There were several issues discovered during the initial flights. First, the VTX had issues on low power and as a result, I couldn't see it in the goggles. I had to manually change the vtx power on the OSD before each flight. Unfortunately, the speedybee app didn't have the programming tab which allowed me to change the vtx power level dynamically. Secondly, it required a lot of reflex, which required quite a few adjustments. Lastly, the D8 receiver was terrible. I suspected as much, but wanted to test the range anyway (which ended up being about 150-200meters). There was also one more issue where there were 2 failed launch attempts where it made some strange screeching noise instead of spinning up the motor. I am not sure if there is an issue with the ESC at this point.

However, the airframe was a success. While KF airfoils are great for LOS, a real airfoil produces so much more lift that it is much more efficient at lower speeds and power levels. I was able to cruise on 3s at around 15% throttle and a 9 min flight covering 6km coming down with around 3.6v. I also flew it on 2x 2s550mahs in parallel which required just under 20% throttle to maintain altitude and covered 7km in 11mins with a resting voltage of over 3.7v. This is going to be a very efficient cruiser once the issues are sorted out. Unfortunately, it weighs more than I would have wanted, but the current wing loading is still very low as it lands easily with no throttle.

Update 1/19/21: I swapped out the VTX to the FX799T since I was getting a lot of dropouts. Weight is now 205g dry.

Update 1/20/21: Video issues are resolved, but I couldn't get a good range test as the gusty winds were pretty much the limit for this plane. At one point, I gave it full right stick and it continued to bank left. The only thing I could do was bank left in a big circle to come back around to land. I was however able to get 1.6km on the xm+, which is the farthest I've gotten on the internal antenna.

Update 1/21/21: Replaced the left servo since it was failing. Not sure if that was the cause of the banking issue during the last flight. I also trimmed away a lot of the foam in the back to allow better airflow to the props.

Update 4/14/21: It didn't get enough speed and came down during launch, but even though I disarmed, the launch sequence hadn't completed and it continued to spin the motor while on the ground burning it out.