La Herencia - Norway October 2008
The old engine and cowling made by my father. |
The fuel engine was a .120 four stroke engine with a 14x8 APC propeller. Barely enough to get this hog off the ground. |
The old fuel tank took approximately 300ml of nitro fuel. |
By coincidence the old and new engines weigh almost the same. |
But the electric motor has plenty more power than the olde engine. |
Here's the downside to the electric motor. Two heavy 4 cell lipo battery packs. A total of 9700 mAh connected in... |
The batteries and ESC together way over 1 kg. That's almost three times the weight of the fuel tank originally mounted... |
I'm new to motors of this size, so a thorough bench test was necessary. I almost took this table for flight! |
The engine peaked at about 50 amps. That's about 5 times the maximum current of a circuit in a common household. |
The tachometer is showing 6600 rpm, but that's after the the voltage level had decrease by a couple of volts from its... |
At first I installed the engine with an angle down and to the right to compensate for the propeller rotation. I then... |
The motor with the ESC installed directly underneath. This is the place with best air circulation in the entire plane. |
On-off switch for current to the motor. Each time I connect it a large spark flyes as the capacitors in the ESC start... |
The ESC doesn't have built in battery eliminator for the receiver, so I had to buy an external one. |
Under the hood. From front to back: The on-off switch for the motor. The external battery eliminator for the receiver.... |
I knew I would have to open and close the hood often (and potentially fast to avoid a fire after a crash). That's why I... |
There was plenty of free space in the plane before I mounted the batteries. |
Aluminum frames for holding the batteries. I created these from bicycle bottle holders. |
The lipo batteries are mounted so as to be released forward and downards in case of a crash landing. Velcro bands are... |
I had to make a new cowling from scratch, and decided to go for empty fuel cans as a starting point. |
The oily material is hell to glue. I ended up using epoxy and tiny screws. The epoxy brakes off, so I would try Tec7 if... |
The finished cowling. |
The cowling can be taken on and off easily with a couple of nuts. That's very important, because everybody wants to see... |
Two bucks for a new pilot. Flown in straight from Hong Kong. |
The plane needed bigger wheels, and therefor also bigger wheel cowlings. So I built the using balsa wood. |
Balsa is such a friendly material to work with. Especially when you're using a dremel. |
A lot of sanding later. |
I put a spring on the wire of the old landing gear, in order to make it a bit more flexible. |
The landing gear with painted and styled wheel cowlings. |
The wings are held together with with two rods and four wires. |
I hope I never have to take those wings apart. |
The ailerons are connected by a carbon rod. |
The body is ready to fly. |
Fully mounted and ready to go. |
Top view. |
Front view. |
Total weight: 7 kg. |