Quadcopter not taking off ... lifts off a little but shakes and wobbles

anshulkatta · September 04, 2016, 06:53:26 PM

my configuration - X frame DJI F450

ESC - 30 Amp

Motors - 2212 , 1000kv * 4

Props - 10 * 4.5

battery - LIPO - 11.1v , 3s

Flight controller - CC3D

my quadcopter is not lifting off correctly , it wobbles , added a video link on youtube , please help regarding it.

As far i checked 1 and 3 motors are spinning CCW and 2 and 4 are spinning CW.

Props are respective on the motors according to CW and CCW.

Please help if i screwed something wrong.

VID link -

ashimda · September 04, 2016, 07:17:43 PM

I think motors 1&3 are supposed to spin cw and 2&4 ccw.

anshulkatta · September 04, 2016, 07:29:35 PM

but then how does it even take off then..because then it should flip and not take off right

K K Iyer · September 04, 2016, 07:58:35 PM

@anshulkatta,
Saw your video. Never saw that type of behaviour earlier!

Quote from: ashimda on September 04, 2016, 07:17:43 PM
I think motors 1&3 are supposed to spin cw and 2&4 ccw.

On my ST360, the front left and rear right are CW.
Same on my mini Intruder.
Pl try resetting accordingly.
Regards.

Mohammed Naveed · September 04, 2016, 08:00:36 PM

Well just try switching The motor rotation 1and 3 cw and 2 and 4 ccw. And it looks like there is issue with the gains. Lower your PI gains slowly till there is no wobble

anshulkatta · September 04, 2016, 08:07:49 PM

how to tune PID , i have less idea about that ,

but what i do is move the throttle trim to up a little bit then only quadcopter flies...

few days earlier it used to lift off suddenly at low throttle values itself without trim..

Darshan for multirotors · September 04, 2016, 08:48:37 PM

Adjust your min throttle value according to your tx.
For PID tuning-

September 06, 2016, 04:36:09 PM

[Before reading the rest: after seeing the video couple of times, need to ask 2 things: have you calibrated the sensors right ? Also check if the FC is secure in place..]

If you have wobble on take-off , or slight wobble after you provide stick inputs [ Forward - Pitch / Sidewards - Roll ]

i have 2 below suggestions..
1. The Flight Controller placement on the Quadcopter should be placed in area where CG is expected [Lines between parallel Motors line cross ] .. Example in the character [X] the Upper part of this character where we get symbol like [v] . it should be at the middle or Little bit Up towards nose.. as shown in image below.
2. Do yourself a favor by getting wireless module[Bluetooth or 3dR] of PID values on your FlightController.. unless you want to connect USB for testing each minor changes.. [optional]

PID just tells how aggressive your QUAD needs to be. and how well the Quad responses on turn and bank maneuvers ..
Default PID should be fine to get the quad in air..

[but still for some Quad's the frame, design would be such, default PID's would not work.. because of balance of frame quad may drift towards nose or tail section.. [require accelerometer trim]..
if Vibration or oscillation is seen, PID tuning may be required unless Frame specific Mixer is used or Frame is manually balanced with components like Battery.. like example: Diatone White Sheep 500, which is tail heavy]

anshulkatta · September 06, 2016, 05:11:12 PM

Quote from: on September 06, 2016, 04:36:09 PM
[Before reading the rest: after seeing the video couple of times, need to ask 2 things: have you calibrated the sensors right ? Also check if the FC is secure in place..]

If you have wobble on take-off , or slight wobble after you provide stick inputs [ Forward - Pitch / Sidewards - Roll ]

i have 2 below suggestions..
1. The Flight Controller placement on the Quadcopter should be placed in area where CG is expected [Lines between parallel Motors line cross ] .. Example in the character [X] the Upper part of this character where we get symbol like [v] . it should be at the middle or Little bit Up towards nose.. as shown in image below.
2. Do yourself a favor by getting wireless module[Bluetooth or 3dR] of PID values on your FlightController.. unless you want to connect USB for testing each minor changes.. [optional]

PID just tells how aggressive your QUAD needs to be. and how well the Quad responses on turn and bank maneuvers ..
Default PID should be fine to get the quad in air..

[but still for some Quad's the frame, design would be such, default PID's would not work.. because of balance of frame quad may drift towards nose or tail section.. [require accelerometer trim]..
if Vibration or oscillation is seen, PID tuning may be required unless Frame specific Mixer is used or Frame is manually balanced with components like Battery.. like example: Diatone White Sheep 500, which is tail heavy]

Great your suggesstions looks pretty serious to me....

1)i was totally unaware of flight controller position , the calibration is fine , the FC is on the level , i will post the image while calibrating , CC3d Librepilot shows the exact plane of the FC ....

but important thing is the direction and how it is sticked to quad , i will try placing FC on top , now its placed in middle next to battery ...will put it up side ...also how do you guys stick the FC to quad , cello tape ??

2) dont know if cc3d is capable of bluetooth or wifi attachment...will check it up..its a pain to remove props and then calibrate and then put it again...

3) definitely a PID problem , i have to increase trim values to get it up in the air and that too just few cms...

thanks

Balakrishna Reddy · September 06, 2016, 07:02:47 PM

Do not use cello tape. Use double sided sticking tape and make sure that it is securely sticking to the frame so that it wont loose in mid-flight which happened on my first flight.
You can use cable ties as well. As mentioned by vibrant hobbies it is better to have a bluetooth module so that your work is easy.

ashimda · September 06, 2016, 08:31:01 PM

Quote from: anshulkatta on September 04, 2016, 06:53:26 PM
As far i checked 1 and 3 motors are spinning CCW and 2 and 4 are spinning CW.

According to this your motors are spinning the wrong way.
Usually when a quad flips at take off, your motor positions/ rotation is the culprit.

K K Iyer · September 06, 2016, 09:21:14 PM

@anshulkatta,
Four of the replies so far suggested that your motors are spinning the wrong way.
Why not try correcting that!

Kartik.is · October 10, 2016, 08:37:05 PM

Because your quardcrafter motors were not running together

Quadcopter not taking off ... lifts off a little but shakes and wobbles

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