Micro Wing with KF airfoil

Build overview

Introduction:

This is my first model built using a KF airfoil. Wings are a great way to test and learn about aerodynamics since they're so simple and easy to build. I built this to see how a KF airfoil compares to a flat wing and also to see the perfomance difference of larger electronics on a smaller frame.

Components ($30):

  • 2x 3.7g servos with optional rod regulators
  • Emax MT1804-2480kv
  • Turnigy 10amp esc
  • 4 channel receiver
  • 5x4.5 prop
  • Dollar tree foam board
  • 2x push rods
  • Colored packing tape
  • bamboo skewer (spar)

Conclusion:

The overall build was quick and painless. The CG was also fairly easy to find using an online calculator. With the first unpowered test glides, I found the CG was off by only a few centimeters. I am also testing the use of rod regulators for the first time to see how reliable they are. Total weight without batteries ended up at 70grams. Initial thrust tests with a 2s battery for the 5x4.5 prop ended up being at about 160g thrust. I had to use slightly larger batteries to balance out the cg and the initial AUW is going to be 100g. I don't anticipate unlimited verticals with this weight, but it is definitely possible if I switch to 3s instead which should provide me upwards of 200g of thrust.

Update 1: The maiden flight revealed that the elevons were too small and the motor needed some thrust angle adjustment. It flew, but was very difficult to keep in the air.