Interesting. When you say you’d not meant to put it near softserial - do you mean you accidentally connected the RX to a softserial port?
Actually, thinking about it, blackbox logging was enabled, I’ll take a look at those and see if there are any clues.
Yes I think I’ll do that next 
Also try checking the stick end points (1000-2000)
When I did my 7", I used uavtech’s presets. That went bad. Grinding hot motors etc. The pd was far too high. Stock bf 4.2 was ok though.
I had a single wire receiver on it. Just TX from the Receiver to RX on the board. Since I didn’t need the other wire on that UART I used soft serial to put it on another serial port with the LED pin so I could put GPS on the quad. That FC is very short on pads, it’s an F411 and not new.
Anyway it was running BF 3.5.7 (I think). I don’t think it should have, but something odd happened on the RX from the receiver. The packets were not getting through quickly.
In that video I had a dodgy antenna as well. I fixed that and is still performed bloody odd until I returned it to it’s original wiring and config.
Quick question(s) on ESCs.
Presumably I don’t need to worry about ESC calibration? On planes I do the whole power on with stick up thing, then reduce to zero to calibrate. I’ve never had to do that on quads…?
It’s a BLHELI-32. What config app do I need - there seem to be loads. I have BLHELI Configurator on my machine here (might be a bit old) which seems to connect ok, then when I hit ‘read setup’ nothing happens. I had to reverse a couple of the motor directions - I did this using BF4.3’s nifty motor direction tool which is very cool.
I shouldn’t need to connect to or change any ESC settings just to get up and running, should I?
If d-shot, you don’t need to calibrate.
If running 6s, put the pwm to 24khz. When I went from 4s to 6s, it kept desyncing / cutting out. 24 is good for 4 or 6s
Another little thing…
I soldered the receiver to RX/TX4 because it was in a nice easy place on the back of the board, vs RX/TX1 which is the default and on the side of the board. I turned off the MSP toggle and changed the serial RX from UART1 to UART4.
This a problem? I’ve just reflashed to BF4.2.11 - tempted to resolder the receiver to UART1 just to keep everything as standard as possible.
Right, really must do some work now! 
Odd, the schematic for the board says UART 4 is “Vacancy”… so why did they have MSP attached to it?
I guess in case you knocked the USB connector off… hmmm…
Still I don’t think it should be a problem, however experience tells me it may be worth switching to the default of UART 1 just to check. (as you have done)
After flashing you did say yes to “custom defaults” didn’t you?
Your motor mapping is correct and you’ve mounted your flight controller with the arrow pointing forwards? (Or adjusted it in CLI to be correct?)
From experience its always best to check the simple things first when fault finding 
Also is the esc - fc loom fully plugged in? It looks like its slightly out but could just be an illusion 
Well spotted Sir.
YESSS!!! It works!
So, as a software developer, I know never to change more than one thing at a time as you never know what the hell is doing what.
Yeah I completely ignored that…
Er, I think that’s it. Hovers beautifully!
So no real clue what was wrong then… 
Yup, utter muppet. Still, it works, and I can very slowly tweak one little thing at a time in terms of tuning now. Going to do another hover in a sec in the garden with 6S and 7" props, then might take it to a big field tomorrow AM and have a very gentle fly about.
Oh, what a rollercoaster. 6S and 7" props back on, same problem as before. That means it’s the props, since it was also doing the same thing with 7" props and a 4S battery this morning (albeit less aggressively).
Could it be a certain amount of load on the motors causing them to spin up? In Acro mode, they spin gently when armed and it doesn’t take off until I raise the throttle, then it shoots up. Going to have to do some Googling.
I notice when using the manual motor sliders in BF configurator, where you can spin them up on the bench, at very low values they stutter a lot. Say, 1005-1010 ish. In real flying situations I think BF considers a minimum throttle signal of 1050 - raising the slider to about 1025 has them spinning smoothly - so that’s probably not related.
Ho hum
Next way to confirm the theory is put the 5" props back on and see what happens then.
Are there differences between the props… apart from the extra 2"?
Hmmm… could it be too light for the motor/prop combination you have there?
i.e. it just can’t get the motors slow enough to be able to lose altitude.
Is there a minimum motor speed setting somewhere?
Just thinking out loud. Could it be airmode kicking in too aggressively?
That was an idea I had and is linked to what I said I think. It’s certainly worth trying without it on.
