Discussions

The Phoenix is reborn in new form! The skyhunter airframe that previously housed my APM 2.5 has been upfit after the last crash with a Pixhawk autopilot and the components listed below.

The plane flies well. So far I've logged about an hour of manual flight time and an hour of FBWA flight time as I tune in the PID control loops.

I am seeing a few different problems I'd like help diagnosing:

1. When switched to RTL or autopilot the airframe becomes unstable and begins to behave erratically before I switch back to MANUAL to recover. This can be seen at about 30% of the way through the attached log when the plane proceeds to make three circles and enter a spiral. I've also seen the error "Bad compass health" intermittently during startup. Could be connected?

2. The telemetry link that used to work out over multiple (8+) miles is now working slowly with link degradation after only a few hundred yards. This can be seen in the video. the dragonlink system is new. I was previously on 2.4GHz. Could these be interfering?

3. After a short flight (10 minutes) my ESC was beeping to indicate a radio glitch. "ESC detected unusual signals or loss of signal on throttle wire". Could my power scheme be causing interference between devices on the plane? See PDF.

Interested to hear any recommendations or tests that can be performed. Has anyone else seen this type of behaviour? The reason the plane is being upfit with the pixhawk is because my motor shorted out and my APM was bricked when the power module overheated. I'd hate to repeat poor power distribution practices and repeat the failure.

Let me know if any additional information is needed.

Thanks,

Zach

SPECS:

Airframe - Skyhunter 1800mm

Autopilot - Pixhawk version 2.4.3

Telemetry - RFD900 TX/RX

GPS - Ublox NEO-7N

Receiver - DragonLink V2

Transmitter - Turnigy 9x DragonLink V2

ESC - Castle Talon 90Amp 

Motor - AeroDrive SK3 3542 800Kv

Antenna Tracker - Pololu Servo Controller

Video Tx - Boscam 1000 mW 5.8 GHz with Blubeam Antenna

Video Rx - 5.8GHz with 10 turn helical

Files:

Skyhunter Wiring Schematic - Skyhunter%20Wiring.pdf

Example Flight Log - 2014-07-26%2019-52-37.tlog

Airframe Pictures

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