Quad is spinning on take off

I finished my build last weekend.

-TBS style frame

-APM 2.6

-Sunnysky V2216-12 800KV motors

-Hobby King 30A Blue ESC (f-30)

-GPS-6M+HMC5883L Compass module

-3s 5000 mah 20c LiPo Zippy

-3DR Power Module

-Hobby King Orange receiver and Futaba T8FG Super transmitter

The issue I am having is that immediately upon take off the quad spins out of control.

The steps I have taken so far include:

Ensuring motors are securely fastened, prop installation and prop directions are correct
Re-installing the firmware on my APM 2.6 (many times)
Re-installing the firmware using X style frame type (where I was using the "Spider" style frame before)
Resetting the APM in the CLI and re-installing the firmware
Calibrating the ESCs together
Ran the Test>Motors in the CLI to ensure that I have the motors hooked up properly
Ran the Test>Compass in the CLI to ensure working compass as well as the GPS
Adjusting the trim via my Transmitter (I can get it to spin the opposite direction but doesn't settle out)
Using the "Save Trim" setting in the Extended Tuning menu to try to trim out the spinning (same outcome I can over correct, but not correct the issue)

Today a friend gave me a tachometer and I noticed that at 50% throttle both of my counterclockwise motors seem to spin at about 1.5-2k rpm faster than the two clockwise motors. I ran this test about 3 times with the same results.

I also ran the ESC calibration and noticed that when I am at the part of the ESC calibration where the motors power on all of them seem to run at the same RPM at about 30% and 50% throttle.

This leads me to believe that there may be an issue with my APM 2.6. I was wondering if anyone had any ideas on this. I am new to builds, have about a years worth of experience flying a RTF quad, don't rule boneheaded mistakes out :)

Thanks much!

Jason

I found it mentioned somewhere here that the IMAX setting for yaw by default for larger high thrust to weight ratio copters just isn't giving the FC enough throttle authority to manage the torque effect produced by said large thrust to weights.... It was an obscure mention of what this "IMAX" setting governed.. I simply added two and two to get my solution for this uncontrolled rotation at takeoff on large high t:w copters...

So my scenario...

Equipment... A 700mm hex+ at 5.5kg with six 50amp multistar motors, at a 300amp max with a rough t:w of 4.2:1

Software... Copter 3.3.3

Problem... Craft would rotate clockwise at takeoff at a pretty decent rate... Several degrees/second maybe 10 but thats a rough guess...

Solution... IMAX under yaw PID setting was changed from 100 to 450 which I believe is its max value. This change and only this change enabled the craft to hold heading without torque yawing... This is not to say that less wouldn't be better, increasing other values is of no help, or that further tuning isn't required to really stabilize the yaw especially during forward flight as I have seen where they like to wander or drift a bit left to right....

Last Thoughts... So if increasing the yaw's throttle authority gives the FC the ability to use what is physically present on the craft closer to its true potential then why would you want any IMAX setting for roll, pitch, or yaw to be anything other than maximum? Wouldn't that give the craft the ability to sustain position again greater resistance IE wind... I don't understand the low limits set here by default why wouldn't they be maximum by default.. Anyways headed off on a different argument there, and I hate to answer a question with question but there it all is...

Walt

Replies

Jason Ching January 19, 2018 at 12:52pm

It’s been years since I’ve dealt with this but I recall that I purchased a new APM and that seemed to solve the problem leading me to believe that that I had a faulty sensor or other hardware component.
babak_ea January 19, 2018 at 12:14pm

I Have same problem

pixhawk , latest ver AC3.5.4

hexacopter

tiger motor mn3510 kv 360

tiger esc 40a

AUW 5.4kg , 2.7kg fram + 2.7kg battery (Lipo 6s,22A)

battery install at CG in bottom the copter

use mag+GPS with 30cm distance with any electrical power system

many times Re-install and calibration ACC,Mag,Radio,... but no used

changing Kp,KI,KD in yaw direction but no used.

I notice that one of the motor (Southwest) slower than the other! but flying

with increasing yaw Kp, solved 45 degree Cw in take off but in backward cruise when release stick spinning in CCW about 360 degree!

also when decrease throttle for descent spinning in CCW

latest flash log:

Log File C:\Users\...\AppData\Local\Temp\tmp5B3C.tmp.log
Size (kb) 3669.646484375
No of lines 45213
Duration 0:03:27
Vehicletype ArduCopter
Firmware Version V3.5.4
Firmware Hash 284349c3
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = GOOD - mag_field interference within limits (9.50%)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.19, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = FAIL - Motor channel averages = [1428, 1506, 1387, 1538, 1640, 1193]
Average motor output = 1448
Difference between min and max motor averages = 447
Test: NaNs = GOOD -
Test: OpticalFlow = FAIL - FAIL: no optical flow data

Test: Parameters = FAIL - 'THR_MIN' not found
Test: PM = GOOD -
Test: Pitch/Roll = GOOD -
Test: Thrust = GOOD -
Test: VCC = GOOD -

2018-01-18%2013-38-09.bin
Serdar GOKSAL October 7, 2016 at 8:25am

I have the same problem with

Board APM2,5 APMPRO

Firmware ArduCopter V3.2.1 (36b405fb)

Frame type : Tricopter

board orientation YAW90

GPS orientation YAW45

While trying to take off with mode stabilize arducopter can not control the yaw and starts spinning.

Corrections from the remote control does not help to stabilize the rotation .

Serdar

all accel calibration is done facing the vehicle north.
Walter Holliday September 4, 2016 at 12:20pm

I found it mentioned somewhere here that the IMAX setting for yaw by default for larger high thrust to weight ratio copters just isn't giving the FC enough throttle authority to manage the torque effect produced by said large thrust to weights.... It was an obscure mention of what this "IMAX" setting governed.. I simply added two and two to get my solution for this uncontrolled rotation at takeoff on large high t:w copters...

So my scenario...

Equipment... A 700mm hex+ at 5.5kg with six 50amp multistar motors, at a 300amp max with a rough t:w of 4.2:1

Software... Copter 3.3.3

Problem... Craft would rotate clockwise at takeoff at a pretty decent rate... Several degrees/second maybe 10 but thats a rough guess...

Solution... IMAX under yaw PID setting was changed from 100 to 450 which I believe is its max value. This change and only this change enabled the craft to hold heading without torque yawing... This is not to say that less wouldn't be better, increasing other values is of no help, or that further tuning isn't required to really stabilize the yaw especially during forward flight as I have seen where they like to wander or drift a bit left to right....

Last Thoughts... So if increasing the yaw's throttle authority gives the FC the ability to use what is physically present on the craft closer to its true potential then why would you want any IMAX setting for roll, pitch, or yaw to be anything other than maximum? Wouldn't that give the craft the ability to sustain position again greater resistance IE wind... I don't understand the low limits set here by default why wouldn't they be maximum by default.. Anyways headed off on a different argument there, and I hate to answer a question with question but there it all is...

Walt
Pat Roy April 27, 2016 at 9:52am

I had this same problem and I know this thread is old but the fix IS to recalibrate your ESC's. You may think your ESC's are right but they are not.

You may also make sure that from SEVERAL different sources you have the correct direction set on the motors. I have seen two different diagrams for a quad on APM where the number one motor was seen as clockwise and it is in fact NOT supposed to be clockwise.
- This reply was deleted.
  - Jason Ching May 10, 2016 at 2:33pm
    
    Sounds very similar to the problem I was having. I fiddled with my computer for a long time 3 months I think - recalibrate, check escs, replace components etc etc. I ended up forking over extra money for a new computer and it seemed to fix the problem. I suspect it was a faulty sensor.
This reply was deleted.
- Jason Ching December 11, 2015 at 2:25pm
  
  Sorry this was so long ago. I think that this thread is from before I replaced my APM.
  
  I think what I had was a faulty barometric sensor or something similar.I replaced the computer/APM and it seemed to fix it. Hope this helps.
Jason Ching March 8, 2014 at 12:06am

Tried to tune PID settings.

I tuned it following the Dave C method : http://diydrones.com/forum/topics/arducopter-tuning-guide

P and D values were really low compared to similar spider style builds like this one: http://www.diydrones.com/profiles/blogs/tbs-disco-first-flight-report

For P I got 0.0020

For D I got 0.0005

I tried it several times and rested on those numbers. Any higher and I would get strong oscillations.
Jason Ching March 6, 2014 at 12:58pm
I am not entirely sure what I may have changed but the spinning is pretty much under control now. What I did was essentially take apart everything and rebuilt it.

Now it's not spinning like a top, but instead the spin is correctable with a tap of the yaw/rudder in the opposite direction, However when i do this the quad just keeps moving the in that direction. Same goes for any pitch or tilt maneuvers, the quad starts to keep going in those directions - a good adjective would be "sailing". Any clue as what this might be indicative of?

Since the rebuild I have:
- Re-uploaded the firmware
- Changed all flight modes to stabilization - also tried stabilization simple mode
- Gone through the Initial Setup wizard
- Re-calibrated the ESCs (together)
- Calibrated the accelorometer several times as I figured this is what was causing the lack of stabilization (in both the wizard and in the CLI
I was told to try to see if there is a way to adjust the gimbal gain I might take a look at that when I get home.

Wondering if anyone had suggestions.

Thanks!

Jason
- This reply was deleted.
  - Jason Ching March 7, 2014 at 8:14am
    
    When I correct for the any motion including yaw it will continue to move in the opposite direction of the original movement. It usually yaws, right, rolls right and pitches forward a little on take off so I have to try to correct for all three movements right off the bat.
    
    I really have to work hard with the transmitter to get it to stay in a relatively small area, which isn't right to me.
    
    Centering the sticks does make the copter frame come level with the ground and stay at a fixed height, but it will continue to move sideways, either backward/forward and yaw in whatever direction it was last going and carry whatever speed it was moving at.
    
    To me centering the sticks should make the copter level out and stay in a relatively fixed position when in stabilize mode.
    
    I will try to get a video up. I will also give loiter a try.
    
    Thanks for the help so far, I really appreciate it.

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Quad is spinning on take off

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