1st Flight, 1st-3rd crash, 1st Prop break.

[TAZ427]

That was fast. It seemed like one motor didn't want to go and so it would flip whenever it came off the ground.

It would rotate left and right with rudder input.

Is this more likely a motor or ESC problem. If it's an ESC then I've got an issue as I've got a Q-brain quad.

Here's my build details.

FC: KK2.1.5 (1.6 FW)
ESC: Q-brain 25A
Motors: Turnigy L2210C 1200KV
Props: 10x4.5 CW/CCW
Batt: 4000mAH, 3S, 30C
Radio: Turnigy 2.4GHz 6CH FHSS
Frame: Q450

When preparing, I checked rotation of each motor and confirmed CW, CCW, CW, CCW (had to flip direction on one motor) checked again, confirmed the correct props when putting it on (tripple checked, and checked again after first flip - never got 2' off the ground before flipping.) Tightened down the props pretty well, double checked before attempting to fly. KK2.1 setup in Quad - X-Mode, went through all settings to make sure it was configured to know good initial settings.

Verified ESC programming before flight. Performed ESC Cal using KK2.1. After doing a balance calibration I did the pivot each blade down to see them spin up test (i.e. verified KK had correct motor order)

Set autolevel to AUX switch and had aux switch on. Verified each of the A, E, T, and R (had to reverse a couple of them.)

Any thoughts on this?

 

[Toymaker]

I have completely different hardware, however I had the same issue. I had a couple problems. I had and issue with two ESC control cables being swapped. I fixed that and then discovered I had two receiver channels swapped.

 

[TAZ427]

Yeah, I checked the motors before and again afterwards, all are spinning the correct way. I had one that I had to swap wires on initial setup, but had did it before the first flight.

Also, the kk2.1 lets you test the A E T R settings via the LCD display. I had checked these and reversed two of them have correct orientation before flying.

It actually appeared as if one of the motors didn't want to spin up enough.

 

[Toymaker]

What I'm talking about has nothing to do with motor rotation. The control cables were swapped with each other. Make sure right front motor is plugged into the right front pins on your flight controller board. As well as all the others. I ended up testing mine with props by holding (very firmly) the frame. Then throttle up almost to hover. then tilt the frame. It should fight back significantly to hold level. When I first did mine(the wrong way) as I tilted it it tried to correct the same way it was tilted causing it to want to flip.

 

[TAZ427]

Gotcha, yes, I checked this as well preflight. Dipping each motor and making sure the one I dipped and only it spun up as it would to try to bring up that motor. I had the throttle low so only the low one should fight to come up for leveling.

 

[Toymaker]

How about the transmitter connections? are they all in the right connectors? When I had them swapped, I tried to correct and it made the motion worse. Test this by anchoring the Quad down and see if the correct motors are increasing RPM with the expected stick input.

 

[TAZ427]

Yes, that was what I was saying before. The testing menu on the KK2.1 lists out A E T and R and the input levels they are getting from the Rx. I had my Tx in mode 1 so had the right and left sticks swapped, changed over to mode 2 to correct, then A E T and R matched up, but had two of the channels backwards which I corrected with the reverse switchs on my Tx.

 

[TAZ427]

Here's a video w/ props of. Autolevel turned off, showing uneven spin up of motors and in particular one not spinning up w/o a fair amount of throttle applied.

I re-verified all settings, and re-calibrated the Q-Brain ESC multiple times via the KK2.1 board. After reprogramming the ESC's the slow motors would actually be on different ESC's, making me wonder if my KK2.1 FW isn't messed up.

 

[Toymaker]

Video is private...

 

[TAZ427]

Video is private...

Oopps, Just changed it to public access.