C-130 Crashes! Fixed! And back into the air!
After several successful flights, my new 50' C-130 design crashed, spiraling into the ground. Having some fun with the crash investigation (see video below), my theory is that when I flipped the flight controller to Return to Home (RTH), the computer suddenly set to full throttle, causing the rubber bands holding the props onto both motors on the left side to break, leaving only the two on the right. This resulted less lift on the left side of the plane, resulting in wing stall and thus the leftward down spiral.
I used rubber bands on the 6 bladed 5x4 props as the typical prop saver O-ring didn't fit. So I switched out the 6-bladed props for 4 blades (also 5" width, 4" pitch) as I was able to get the O-rings to fit. After I printed out a new nose and re-supported the nose wheel, I got it back into the air.
With the new props, it became very clear that I had to maintain almost
full throttle to stay in the air. When turning, I noticed a similar
beginnings of the wing tip stall experienced in the video when at 50%
throttle, and with more throttle the wings leveled off. If there is a plus side, the take offs feel very scale with a long run out and relatively slow climb.
Clearly, I need more power! One options is a 6" 4 or 6 bladed prop, but have had no luck finding anything close. That leaves a faster motor. The current X2305 1450kv motor is made to turn much larger props, and it seems we need 1400kv to keep in the air. Now looking for a faster motor. The easiest option is the Sunnysky x2304 1800kv (or x2305 1850kv). Either of these should add an extra 25% which will definitely help. Not sure if that is enough, or if need to go with a much faster drone motor with ~2300kv.