Hi, I am a newbie, trying to build a first quadcopter for my son to get him interested in science and engineering.

I have a peculiar problem that the quadcopter is not lifting off the ground without flipping.
A video showing the problem is here (See near 0:55 onwards):

For past 1 month I have read tons of forums and seen lots of videos. Here's all that I have tried.

Steps already tried (to the best of my knowledge)

1. Reset of KK board 4-5 times after seeing various videos.
2. Changed 3 ESCs on M3 (with new ones). Changed 2 motors on M3 with new ones.
3. Checked all ESCs are connected correctly.
4. Checked all ESC pins on KK board are correct.
5. Motor directions are correct. Motors spin together. Without propellers, they even seem to be running in sync at nearly the same speed visually.
6. Tried to liftoff with higher throttle instead of slower liftoff. Broken a few propellers. It straight runs into side and drops.
7. ACC calibration (all show 512).
8. ESC calibration by various means. This is confusing at times (see more below).
9. I even flipped the board and the direction so that M1 become M3 and M2 became M4. After doing this M1 started to misbehave in exact same way. This lead me to the conclusion that its not the motors or ESC. Its the board.

Technical Specs
- FlySky FS16 Transmitter
- KK2.1 Board 2.1.x, FW 1.19S1 Pro Steveis
- A2212, 1200KV motors
- 30A ESCs
- Battery: 2200 mah, 25C RC LIPO
- No external GPS etc.
- All settings are here: https://www.dropbox.com/sh/kvhrbzyofii8act/AAC7IJzAvY3JUEc3x5iHzHg4a?dl=0


ESC Calibration

Honestly this is quite confusing. I tried to do this in two ways:
1. With all ESC pins to board connected, powered the board and kept 1+4 pressed.
2. Pulled out first ESC pin (no power to board) and then after pressing 1+4 pinned that in.

In both of these types I see throttle pass-through. Then I hear the first main beeps when trottle is full. But when I drop the throttle to zero, sometimes I hear a small beep from one of the motors and sometimes not.

I have tried ESC calibration atleast 30 times till now. I still don't know if its correct or not.
I didn't find a clear guide on how to individually calibrate them. Do I plugin ESC-1 wire and then remove others and calibrate?

Others
I have not upgraded the firmware. If I understand correctly this is the latest.

I was also considering buying a OpenPilot CC3D board or something else if this board is so difficult to program.

Requesting if someone can guide me. I am residing in West Delhi. If you live in Delhi I would really like if you can talk to me and help me please.

Hi! Welcome to RCIndia.
Here's a quick troubleshoot.
Go to the setting> gyro bubble (img 16,17 from Dropbox attachment) > rotate the kk board/quad along x-y axes. Does the dot move or remain centred?

If there's no movement of the dot, then it's a malfunctioning gyroscope sensor (MPU6050).

Kiran, you are a genius. Spot on. 

It does not moves. Both the ACC and Gyro bubbles are dead at the center and don’t move when I tilt, rotate or whatever I try to do.

So I even did this. I removed the propellers and after arming pushed the throttle half way and made the copter vertical. Even then all motors seemed to rotate at same speed. So seems like the sensors are dead. I also went into MPU6050 settings and tried to change the settings to see if it would revive the gyro. No luck.

I bought this at Lajpat Rai market in Delhi at Everest Electronics. All the things he told me and sold were good.

So at this point what should I do? I guess my options are buy a new KK2.1 board and check the gyro at the shop itself. Or should I consider buying a different board that you may recommend? I read that CC3D is 32 bit and is more stable, but I don’t know that for a fact.
What would you recommend I do and what would you recommend I check when I buy the next controller?

Again, really thanks for your help. We’ve been struggling with this for a while now and somehow I missed checking this repeatedly.

You're welcome

P. S   many kk boards do have the problem with gyroscope.
       Try to get the board replaced (if it's returnable/under
       warranty) If not, there are better flight control boards
       but they do require some programming via PC and
       aren't as user friendly as this one.
       CC3D or Naze32 will do. If you want to upgrade to
       F.C with GPS,  have a look at APM 2.8.

It’s not returnable. But that’s okay.
GPS: Not right now. I’ll start with basics and then try that out.

I had earlier found this post and read through the discussion. I also think CC3D might be worth considering. I do have a MacBook and I see they have a software to program via USB.
http://www.rcindia.org/multirotors/naze-32-vs-cc3d-a-newbie's-story!/

With CC3D or Naze which is easier to get working out of the box? My son is kind of discouraged (he is 9 yrs old) and he thinks this will never fly. I want this to get flying quickly as I want to teach him that we need to try hard and things work.

I will probably buy a new kk2.1 with working gyro (taking battery and esc with me) and a second board CC3D (or Nazeif you recommend).
I can also buy Acro as the second board if that is more easier. Will need to check availability at the shop.

PS: Next time I am in Bangalore I owe you a beer.

CC3D has stm32 microcontroller while the kk is embedded with Atmega328.
The former allows the user to modify/upgrade easily since it's based on opensource software.

Since, the main motive of the build is to hover with basic flight characteristics,  any one of them will do.

I haven't used a kk 2.1 in almost 4 years, but I remember the firmware that came stock with it (1.9S1) had this same issue. It might be worth trying to flash Steveis 1.19S1 or RC911s firmware again before replacing it. All you need is a cheap USBasp tool or even an Arduino.

If you do end up replacing it, both the CC3D and Naze are pretty outdated because they have the F1 processor. Even though on a 450 size quad you don't need extreme performance, it may be worth picking up something with an F3 or F4 since F1 isn't supported by newer firmware.

I think for the price of another kk or cc3d (may be little more), you can buy a f4 flight controller.
Its not difficult to program it with INAV or betaflight firmware.
You can also get much more features like altitude hold, position hold (gps), rth (gps) etc.

Note - I went through same route. 450-kk-cc3d. Finally ended up 210-f4

I got the copter working. I got it working with KK2.1 to for now just this weekend. Will experiment more wtih CC3D in near future.
Thanks a LOT for all your help.

share your happiness by uploading video of your flight with your son