ORIGINAL: c_makhija
Hi Jack,
Not blaming spectrum in anyway, i myself use JR/Spectrum. Just wanted to find out if the Go Pro could affect the signal in anyway as this roo has had 100s of flight with this setup but was the first flight with the GoPro mounted on. Unfortunately all was lost in the fire or else the batteries would be on the cycler first thing.
Chatty.
ORIGINAL: JackD
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying ''spektrum, spektrum....'' (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
I know, sorry for putting this on your thread. I just saw it going into the Spektrum doesnt work direction, stopping any possibility of serious analysis of your crash.
I doubt it had anything to do with the gopro. I do have to admit, 1200mah sounds very small. I don't know the discharge rate of A123, but if it where lions, you would not get enough power out of one. 2 1200 is ok, but if one failed (or the switch, or forgot to turn one on like i did) will leave you with very little juice to power your plane...
Again, don't know anything about A123
Later
Jack