Dangerous divergence: FIXED and understood

The last Bastion to fine tune your FC matching your airframe & setup

Re: Dangerous divergence issue: NOT YET SOLVED

Postby afernan » Thu Mar 21, 2013 2:09 pm

throttle stick springed to center? You´r really a kamikaze !
Anyway, happy you found the copter not too damage. On the paper it´s a good idea but I found it too risky. It´s much easy to play with "throttle dead band". I use to have = 100, that gave enough play to stay in PH easily.
Angel
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby LPR » Thu Mar 21, 2013 3:28 pm

Angel

I've played with "throttle dead band" and I did not like the loose feel it gives.
I agree that I'm a little crazy but it works so nice in Alt/Pos Hold and missions. I put up with the inherent danger in manual. I thought I had learned to always disarm before letting go of the throttle, guess not.
One of my favorite things to do with the AQ octo is to give the Tx to people that have never done any RC and watch them be able to control the octo in just a couple of minuets. When I give them the Tx I have the octo set to RTH and then they just move the octo a little and let go to watch it go home. They get comfortable with flying really quick. Of course I tell them that there is much much more to learning RC aircraft but at lease they get one positive experience.
I stand very close to the new pilots and have the octo at a good distance away or I have them inside the house and the octo outside. Without the throttle springing to the center it would be difficult for an inexperienced person to fly it. Most of the time I just use manual mode for arming and disarming and for an emergencies.

Larry
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby Max » Thu Mar 21, 2013 8:39 pm

Larry, throttle sprung to center? Self-flying octo? :shock: That's just nuts, sorry. Either you live in the middle of nowhere or you're very lucky no one and nothing got hurt or damaged (or rather, whoever didn't get hurt are the lucky ones!). If anything, install a spring to pull the throttle DOWN by default... :lol:

Please be safe with these things!

-Max
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby Jdmagoo » Fri Mar 22, 2013 4:10 am

Hey afernan,

Do you have any links to videos showing the divergence issue? I would really like to see this

Thanks

James
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby LPR » Fri Mar 22, 2013 4:20 am

James

I you use the search at the top of the page and type in video you'll find the videos the Angel posted in this topic.

Larry
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby JussiH » Sat Mar 23, 2013 12:46 pm

I must confess that this problem has me a bit stumped, and I can not identify the cause of it.

I have had a similar problem way back on 2 X-quads, but for me it was associated with improper ESC ranges, and changing to ESC32 made it go away. For me, I could only make it happen in DVH mode.

I have only seen this on X-quad layouts and I think that all who reported this also was using Xquad mixing so I am beginning to think that its something in the way mixing is handled for that particular layout.

Teramax: Was your craft also a Xquad.

Has anyone seen this happen on any other craft layout?

Angel, can you post your mixer table?
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby skew » Sat Mar 23, 2013 1:05 pm

Mines also a X layout. I use the X mixer in the downloads section.
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby Jdmagoo » Sat Mar 23, 2013 11:20 pm

LPR wrote:James

I you use the search at the top of the page and type in video you'll find the videos the Angel posted in this topic.

Larry


Thanks Larry,

I didn't realise the vids were actually in the attached zip file, I thought they were logs.

Cheers
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby Max » Sat Mar 23, 2013 11:37 pm

The light X quad I have which does NOT exhibit this issue (and I've thrown it around to it's limits in various flight modes) uses +/- 100 for all motors on pitch/roll, unlike the mix table in the examples and d-loads sections (which uses +/- 50). With only 50% of the pitch/roll power applied to those motors, I'm not surprised it would have trouble getting out of difficult situations. If you couple that with large throws on the radio and fly aggressively... then add in some wind or choppy air... could be trouble?

The +/-50 mix table doesn't make sense anyway... absolutely no other multicopter project I've seen uses that kind of mix for a quad X.

So to add to Jussi's question about other frame setups, has anyone experienced this on a quad X with +/- 100 mixing, or a quad +?

-Max
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Re: Dangerous divergence issue: NOT YET SOLVED

Postby LPR » Sun Mar 24, 2013 3:46 am

Max

What Tilt rate P setting do you use on your quad X?

Larry
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