How to get your quad flying well.

[raute]

How to improve your quads stability:

After I first built my quad, it was so instable. I had oscillation even on small maneuvers, when it descended it flipped sometimes suddenly… But now it gets better and better, so I collected the things I have done to achieve that. Maybe it will help someone with related problems.

1) Balance your props:
First, I had EPP1045 props purchased at CNC-Modellsport and they were really bad. Very much out of balance. Now I purchased them at Mikrokopter-Shop and they are so much better. Much less vibration. But Balancing with some tape is still needed, too.

2) Balance your motors:
If your motor bell is not in balance, this may cause vibration, too.

3) Use shorter arms:
Shortening the arms (=decreasing motor-to-motor size) made my quad much more stable. I know, physically longer arms mean higher torque and more force to stabilize… but it seems to be just better to have shorter arms. You will find that opinion in some other posts, too. My theory is that shorter arms reduce vibration and are less bendable.

4) Dampen your sensors:
Dampening your sensors will lead to better readings and better stabilization, because the PID-Controller is only as good as the input data you feed him. Comes crap in, crap comes out. But bad dampening can also downgrade the output if it allows the sensor to move when the quad is accelerated. So be sure that your foam covers the entire surface of the sensor and is securely glued to your frame.

5) Program your ESCs:
As I use Mystery 20A ESCs I can say that they are good… but when you try to program these, it gets very tricky. The manual is simply wrong. Google it, and you will find some hints, there are many others having that problem.
However, it may be good to program your ESCs because the initial setup may not be best for quadrocopters. You may use the following settings: Brake-Off, Frequency-16kHz, Timing-Auto or High, LowVoltageCutOff-Off, GovMode-Off.

6) Check the quality of your Wii-Motion-Plus:
If you use a clone WM+, it may be the source of bad stabilization. Some WM+ Clones (like my first one) seem to be okay in the GUI, but in flight they are way too sensitive to vibrations and cause wobbling and flipping sometimes. Some other clones may not even work well in the GUI. When purchasing a clone WM+ you will never know what PCB is inside, some are better, some are crap.
So I got an original Nintendo WM+ now and it works way better. It is really worth the few bucks more. Additionally I want to point to the itg3205 hack that sounds very interesting. I haven’t tried it yet.

7) Customize your MWC-Software:
Sometimes small changes to the MultiWii Code can improve the flight behavior. As every quad is different, it may help to adjust some values in the code, for example the degree of accelerometer smoothing.

8) Adjust your PID settings:
It is not easy to find the best PID settings for your copter, but if you have problems with oscillations or weak stability you can maybe fix it by adjusting your PID values. For example as I flew with that bad WM+ copy I had much lower P, and so it was flyable anyway. In fact the hover quality was pretty good. However, some fly perfectly with stock settings. Try it on your own.

9) Check your wiring:
One day I suddenly my quad flipped over when I applied throttle to take off. But in the GUI I can’t figure out why. Later I discovered that a loose I2C connector and the vibrations due to the accelerating motors caused these glitches. The same thing may happen to Rx- or ESC wiring. Short cuts due to metallic bolts or bad soldering are dangerous, too. In general - be sure to carefully isolate solder points, connectors and wires.

10) …and tings you never will be prepared for:
Some weeks ago I had a bad solder joint at my ESC capacitor. After searching and searching for hours I thought my ESC was fried. The problem only occurred on high motor speeds and only with props mounted... it was really tricky. Finally I cut the ESCs shrink tube and discovered the problem. What I want to say is: never give up – every problem has a source and can be fixed. Well, sometimes it will be much work and you want to trash that whole thing… but finally, you will get some nice and smooth flying, I am sure.

Maybe you will help me completing the list... So it could be a collection of hints for beginners.

raute#

[maxic31]

Hello raute!
and first of all thank's for your post.
I have a quad WMC and I meet some difficult to configure my copter. Then I try to check all parameters from the beginning.

Your post is realy interresting and i would like to add more information about Mystery ESC.
I have theres :
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9485
and, of course with bad manual.
I had choosen sames param as you: Brake-Off, Frequency-16kHz, Timing-Auto or High, LowVoltageCutOff-Off, GovMode-Off.
And to be sure, I would like to have your feeback about the sounds activity of ESC. I found this list in other forum (RCgroup may be) and it correspond to my ESC ( except 3A 3B ) ==> 12A for me.


1) _ _ * * (longer pause)

2) _ _ , _ _ , _ _ , _ _ , _ _ = 2S lipo

3) _ _ _ , _ _ _ , _ _ _ , _ _ _ , _ _ _ = 3S lipo

Some ESCs (but not all of them) have the following settings. **Note** My 20A has 3A and 3B but my 12A does not.

3A) _ _ _ _ , _ _ _ _ , _ _ _ _ , _ _ _ _ , _ _ _ _ = not sure.. possibly a NiMH battery?

3B) _ _ _ _ _ , _ _ _ _ _ , _ _ _ _ _ , _ _ _ _ _ , _ _ _ _ _ = not sure.. possibly a NiMH battery?

4) ___ , ___ , ___ , ___ , ___ = Auto battery detect possibly. Works with my 2S or 3S

5) _ * , _ * , _ * , _ * , _ * = Battery protection reduce power

6) * _ , * _ , * _ , * _ , * _ = Battery protection hard cut off

7) _ ** , _ ** , _ ** , _ ** , _ ** = Battery protection ignore

8) WWW , WWW , WWW , WWW , WWW = Reverse

9) WW , WW , WW , WW , WW = Accel soft Heli mode

10) W , W , W , W , W = Accel normal Airplane mode

11) * , * , * , * , * = Timing Auto possibly?

12) ** , ** , ** , ** , ** = Timing soft possibly?

13) *** , *** , *** , *** , *** = High timing possibly?

14) \ , \ , \ , \ , \ = 8 Khz possibly?

15) / , / , / , / , / = 16 Khz possibly?

16) _ , _ , _ , _ , _ = Appears to be restore default

17) _*_ , _*_ , _*_ , _*_ , _*_ = Governor off possibly

18) _**_ , _**_ , _**_ , _**_ , _**_ = Governor Heli 1 possibly

19) _***_ , _***_ , _***_ , _***_ , _***_ = Governor Heli2 possibly

20) _****_ , _****_ , _****_ , _****_ , _****_ = Governor possibly [/QUOTE]




For you, after a "restore default", options:
4) and 7) and 10) and 13) and 15) are correct ?

Thank's for your help

[marddi]

For you, after a "restore default", options:
4) and 7) and 10) and 13) and 15) are correct ?

Yes, but you only have to set 7, 10, 13 and 15. Battery detect is auto default, AFAIK. These sounds match my ESCs beeping exactly.. I have four Mystery blue series 20A.
You also may take a look at: viewtopic.php?f=17&t=169
The thread where the "mystery" gets solved is here: http://www.rcgroups.com/forums/showthre ... 342&page=2

raute#

[maxic31]

Oki, thank's marddi !

All is ok for me now