I had really hard mag_field interferences compass in one of my custom copters (see Tridge analysis done in this other topic)
See the mag_field during a normal flight:
The harness arrangement was done randomically inside the two main plates .In particular both red and black lines were independent (not good for mag_field!):
So, I decided to re-route the powerlines by substituting the old harness by independent highly twisted lines for each of the ESC´s starting from the battery. I´ve shortened also the battery cables to the maximum, and also twisted them a bit.
So the result is awesom: It complitely solved the problem (see second Image of a similar flight).
I hope this help others to solve in the root the eventual interference compass problems: lets "twist and shout"!
Angel
Replies
Dying to see some photos! I have been having some issues regarding Random Yaw on my X8. Would twisting wire always be a good practice in main wiring for future reference? I haven't really studied my logs yet, too busy reppairing and balancing props. TIA :)
That's very nice Dani ! Unfortunately twisting powerlines would require a complete dismantling and rewiring of my copter, which I really don't see me doing.
Surely we can't expect all users with yaw problems to rewire their copter ? It worked fine before (2.0.49) so we should be able to get it working fine again.
Hi all,
prior to using 2.5.3 I ha no problems with yaw.
With 2.5.3 yaw would have a will of it's own, wandering about 25º to each side; I believe it must be some kind of process that now is more sensitive to mag interference,
So I followed afernan's advice, high-twisted all power lines and moved the mag a bit further away.
Tested it today, and yaw is back to rock solid.
Thanks! great tip!
Extensive flight test results with new hardware setup
The goal is try to get the best offsets for the better flight. Also to compare the three method we have:
Method 1):
hand rotating (no motors) -43, 30, 25 repeteated again -30,31,17
Method 2):
Using MP / TLOG offline calibration. I´ve got three long fly records (see attached TLOGs)
TLOG
Thro>10%
Thro>20%
Thro>30%
2012-04-02 20-17-35
-21 31 76
-21 31 76
-21 31 76
2012-04-02 19-54-08
-14 34 64
-14 34 64
-14 35 65
2012-04-02 19-00-45
-17 36 89
-17 36 89
-17 36 89
2012-04-02 20-17-35
2012-04-02 19-54-08
2012-04-02 19-00-45
Method 3):
Compass Learn:
Outdoor flight:
After 2 min flight -2,40,-4
After 5 min more -19,39,-14
After 10 min more -18,52,-11
After 15 min -16, 16, -95
CONCLUSSIONS
Looking fordward your comments on this results to try to commint on one method for today until we get another.
TLOGs.zip
Nice one Angel!
He was the one who flew avoid, but unfortunately it is inevitable ... "come on let's twist again"... :P
Very cool! EMI issues are always a pain. Care to post a pictures with twisted pair harness?
That's a great result Angel!
Great stuff afternan !
Did it solve yaw problems you were having ? (if not, what symptoms did it solve ?)
The thing that still bother me is this : with 2.046 till 2.0.55 I didn't have any yaw problems and my wiring was the same as it is now...
Power to my hexa motors is done in a starburst form *. A central feedline from the battery is split into 6 branches heading into each arm
Great write up! Thanks for sharing this information. I almost wonder if this should be a blog post so more people have eyes on it.... Its good information for everyone.
Thanks again!
Clarification:
What I want to say for "independent highly twisted lines" is the following:
From the battery I´ve created four independent lines black-red (- & +) driven to each of the ESC´s. Each pair of +/- cables are highly twisted in order to cancel its own magnetic field by its own. This is done for each of the four pairs of +/- cables .