My third scratch built plane is a departure from the slowflyers I've been building. For this project, I went with a larger and faster airframe. The reason was a discovery of bargain supplies that would make the final outcome about as cheap as the much smaller and slower aircraft I've been designing.
The plane I call the parkFighter is loosely modeled after WW2 fighters. When I say loosely, that is exactly what I mean. I didn't really copy any existing designs but rather just started building. The one thing all my scratch builts have in common is they have to be dirt cheap to build and this one is no exception. Here is what I did.
The airframe is made from bluecor foam.It is cheap and can sometimes be found at hardware stores. To keep things light, foam was glued together to form the basic fuselage. Bulkheads were also made of foam and glued in place. The wings are also made of foam with foam spars to hold the single airfoil shape. Cutting a matching pattern in the fuse also helped retain the airfoil shape.
Electronics were also pretty light using GWS receiver, pico servos and a zagi 20amp esc. For power, I am using surplus 280 class motors from Goldmine. Batteries are also surplus Goldmine AAA nimh cells made by Maxell. A MJ gearbox was added for torque and lower amp draws. For looks and ROGs I added ultralight foam wheels with simple wire glued to balsa mounts.
The final product weighed approximately 9.8ounces with a 6-cell pack or 10.4ounces with a 7-cell pack. The plane has a 38" wingspan and 26" length. To keep weight down, it is set up as an aileron/elevator only ship using 2 servos. My goal was to make a lightweight plane with true vertical performance. Although the final prop/gear combo may change, I accomplished my goal with a 7-cell pack driving a 9x4.7 APC slowflyer prop using a 5:1 gear ratio. With that setup, the plane was capable of slowly climbing when hand launched in a vertical position.
The plane won't win any beauty contests but was very cheap to make and proved you don't have to spend a fortune on brushless motors and exotic kits to build an electric plane with true vertical performance. |
