Lynxmotion HQuad500 Flipping over with any touch of right stick

Lynxmotion UAVs / Drones
1

Lynxmotion HQuad500 with Quadrino Nano

Radiolink 10 CH AT9S

The UAV was assembled per instructions and all esc’s have been calibrated properly. Upon trying to lift off, the UAV wants to lift uneven and the moment any right stick is applied to correct it will flip over. We actually purchased 6 in total and most are doing the exact same thing and none of us can figure this out.

2

No clue how much previous experience you have, so just in case, I’ll go into some detail here). This can be symptomatic of one or more issues in the setup. Obviously don’t try to lift off until this issue is resolved (one crash can be a complete write-off). It sounds like one or more of the motors and/or propellers is installed incorrectly. Remove the propellers from all motors and try the following:

  1. Check that the ESC RC input pins are connected to the correct pins on the flight controller
  2. Check that each of the motors are rotating in the correct direction (as per the manual)
  3. As always, without the propellers connected, connect the battery and start the UAV, then throttle up a bit. By hand, rotate the UAV to see if the right motors throttle up to compensate (ex. roll the UAV clockwise and both motors on the right should throttle up to compensate). Do this for yaw and pitch to verify connections. If they rotate in the wrong direction, then change the pins between the motor and the ESC to check the direction. If the wrong motos throttle up, then you need to swap the motor pins to the flight controller.
  4. If steps #1 to #3 work, and it seems the motors are connected to the right pins, and rotate in the correct directions, then find a location where you can crash with as little damage as possible (i.e. test flight) - like a field with tall grass. Install the propellers but triple check the following: Propellers have CW and CCW rotations (i.e. they are not all identical) and based on the guide, verify that you have installed the right one on the right motor. Also, check that you installed each propeller facing the right direction (the lettering, like 10x4" facing up). HOWEVER, don’t try to fly yet - you likely need to do some calibration (flight controller IMU always needs to be calibrate, so follow the procedure). Even at this step, you likely still need to do some basic calibration of the joysticks.

Making a custom UAV fly requires that every detail of the guide / instruction manual be followed - especially if this is your first time. Even the slightest issue will cause the UAV to fail and either crash, or be lost. Even with everything done correctly, you still need to learn to fly.

3

So I spent a few hours testing a bit last night. I found that by turning down the sensitivity of adjustments, I can better control how responsive the UAV is to right stick input. I double checked all the motors and propellers are spinning the right way and that when the UAV rolls in any direction the correct motors are in fact compensating for the roll.

Next step is to recalibrate everything and go from there.

4

Ok, everything was recalibrated and at least in horizon mode we have lift off and can move around in air, however, the UAV will not go back to level on it’s own and in angle and baro modes it will either not have acceleration or no pitch. It’s pretty much impossible to fly the way it is because it’s almost as if the gyro is not finding zero point.

5

Double check that the flight controller is mounted in the correct orientation on the drone, and you will need to go through the gyro calibration, and before taking off, ensure the GPS has a lock. Are you also certain that you’ve assigned the right stick on the remote control to change the flight mode (and that you have not been accidentally flying in the same mode). For example in MultiWii, you need to configure the input and assign the modes before the flight. You can also check the drone’s orientation within the software to see that at least it knows its orientation correctly.

6

I can confirm which stick is controlling the aux port for flight mode and we have been able to see differences to the extent of where it’s at. As far as gyro calibration, where is that calibrated at?

7

All of the calibration should be within the software (MultiWii Config or WinGui, whichever you preferred after having gone though the Quadrino FCT software). For example MultiWii:
http://www.multiwii.com/wiki/index.php?title=MultiWii_GUI

You might need to calibrate:
Accelerometer: http://www.multiwii.com/wiki/index.php?title=Calibration_Accelerometer
Gyro: http://www.multiwii.com/wiki/index.php?title=Calibration_Gyroscope
Compass: http://www.multiwii.com/wiki/index.php?title=Compass_Calibration
Each ESC: http://www.multiwii.com/wiki/index.php?title=ESC_Calibration

8

Well we calibrated acc, mag, compass, each esc again and gyro. Also ensured gps was locking on prior to arming and the thing is still erratic no matter what we try. We are done for at least today as a motor mount snapped after the uav shot off to the right and I was forced to bail on throttle. At least it is flying to some degree now, however, it’s not stable at all at this point.

10

We’ll discuss internally and see if we can narrow down what might be the issue. We’ll get back to you as soon as we have news.

11

Hi creaman,

First it would be nice if you can have a look at our tutorial page HERE regarding sensor calibration.

Once you are connected in WinGUI and looking at the transmitter input, are you able to move each channels individually ?
Sometimes you have “mixings” between channels in the transmitter which might cause serious issues.

Also, one common issue is the rotation direction of each motors as well as their matching CW and CCW propellers.

And a final note, if you have no “flight modes” selected there won’t be any stabilisation.

:slight_smile:

12

Hi Sir,

Today we recalibrated all four esc’s, the acc, mag and gyro. We also verified channels operate independently and that they rotate in the correct directions. Additionally, we can confirm operation in horizon mode.

We still have zero in flight stability. The gyro function is working and has been verified, however, the drone will drift off in all directions and will not hover at all without constant input. Additionally, any input seems to kill power and the drone begins to fall.

13

Hi Creaman,

Factoring that all of this was done right, one thing that might be an issue is Vibration.
If you have vibration in your system you might want to change the filter value (HERE).

Note that the “Horizon” mode will not stabilize the “yaw” axis as this is done with the MAG. (HERE)

Make sure your “trims” on the transmitter are centered and showing 1500 in WinGUI otherwise MultiWii will take that as a movement request.

14

Truthfully at this point we’re literally repeating the same steps over and over to no avail. We turned the motors up to roughly 1600 and can listen and watch on screen as two of the motors begin to idle themselves down as the other two stay constant. Once you touch the throttle at all they all level out again briefly and again 2 will begin falling. Running through these steps is honestly beyond what I understand and even the two hobbyshops we took this to were baffled.

15

If you did that without the UAV hovering, it’s a normal behavior of MultiWii explained on their wiki HERE.

16

Another flight test, another broken prop and motor mount. We are now at our wits end. It begins to hover, then decelerates, then it pitches and rolls and pretty much does whatever it wants until you manually correct no matter what flight mode we use. We’ve tried it with and without gps lock, in horizon, acro, angle etc. We have calibrated and confirmed every step repeatedly and still have absolutely no stability in flight no matter which combo we try. We’ve had a hobby shop locally look at it to no avail and ours is not the only one with this issue out of the 6 purchased. At this point we are pretty much stumped having read all the replies trying each different suggestion with none providing any sort of result with the flight operation.

17

Hi creaman,

There are a lot of things mixed in and you are trying things which should only be tried once the UAV is working.

  • Do not try and/or activate any GPS mode
  • First thing to do is to fly un-stabilized with no mode selected

Note: You will still have to “fly” your copter as this is not an auto-pilot. If tuned properly (PID) you can achieve hands off but the copter will drift side to side.

Questions:

  1. How did you calibrate your ESC’s ?
  2. In WinGUI, what do you have as signals from the transmitter and output to the motors?
  3. What about our suggestions regarding the Filter and Vibration?