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Old Jan 07, 2012, 01:27 PM
Who dares wins
Deutschland, HE, Nidderau
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Originally Posted by topgearuk View Post
@ Vimeo Vid... That's not nice to see, but that look's a lot different to what people have been describing which was flipping and lack of control, this is my view look's more like a low battery situation.. All motor's still running and no flipping but not enough power to fly or correct it's attitude.
I had similar issues awhile ago when a rotor screw get loose. This usually happens on the units spinning in the opposide direction.

Bernd
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Old Jan 07, 2012, 01:30 PM
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Originally Posted by llbr22 View Post
+2! RTFM

Btw, all the videos of DJI's dropping out of the sky are user errors, including mine :-)
Wait, wait, wait, that depends on how you define user error.

Sure mine fell out of the sky because I lowered the throttle to less than 10% and it cut-off, the flight conditions dictated the control inputs.

My argument is that there should be ABSOLUTELY NO WAY that the user can react to flight conditions in such a way that should result in a shut down.

My question is still what problem does the 10% cut-off solve? If its a safety issue to remind you that your multirotor is armed, there are different ways to do that without treating the user as an idiot.

But good intentions aside, if this feature results in multis exiting the airspace in a rapid uncontrolled manner then it is MORE DANGEROUS not less.

If we were just having a cordial debate between yuppie backpackers you might expect a long discussion, however, there is an increasing number of videos appearing of DJI products falling from the sky. Sure a certain percentage of them still might be user error or component failure, but there's enough of a trend so that DJI should be working on solving/changing this procedure.

My argument is that this is very easy to make this a non issue by giving the operator to arm and disarm the same option that just about all other controllers have.

I'd also point out, no matter what you may think of this issue, right now its mostly annoying, but if one of these things falls on someone on the ground and seriously injures them it will become a completely different issue and I can't think of any outcome that is good for DJI and/or multirotor enthusiasts.
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Old Jan 07, 2012, 01:38 PM
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Originally Posted by redridinghood View Post
This one was mine. I still don't have an explanation for this, but I have a couple theories. First of all, the ESC (in the M1 position...), which is a Maytech 30A/400Hz model, is properly calibrated, and does not have the LVC set. The connections, even after the crash, are all solid, and it arms and spins up just fine. None of the motors or the ESCs, get much above ambient, even after a 9 minute flight. This crash happened two minutes into the flight with freshly charged 4s-3300 45C packs. Voltage sag, for whatever reason, just did not come into play here. I also had one other incident, prior to this flight, where just as I was lifting off, that same motor quit, and it rolled over that direction. Since it was grass, the only damage was one prop.

Anyway, getting back to my theories, one thing that was common to at least my crash and Ken's (RTRyder...) is that we were both descending at the time. In my case, I was still trying to get the gains adjusted on this setup, and I still had quite a bit of wobble. Getting it down was not so easy. It looks like what happened is that the M1 motor shut down, causing it to roll over to the front-right, and take off in that direction. When the roll angle reached 70 degrees, all the motors shut down, and it dropped like a rock, from about 50-60 feet. There's a couple of things I find troubling about this. First of all, why was there zero compensation attempted by the WK-M, when it lost one motor? Now I expected that with a hex, it might not fly too well with one motor out, but it is clear in the video, it did not even try. It was as if the rollover was commanded by the WK-M.

The second problem I have is that the 70-degree cutoff is only supposed to happen when the throttle was also less than 10%. This part I'm just not sure about. I was trying to bring it down, but I don't think I had the stick down that far. I'm not sure if it is related, but I have noticed that what Ken first reported, about a relationship between overpowering/over-propping for a given AUW, and not being able to dial out the "wobbles". This particular hex setup weighs about 5-1/2 pounds, with two 4s-3300 packs, the DD gimbal and with the GoPro installed. With the "kit" 10x5 props this has a ton of "reserve" power. I found out just how much on one flight where I forgot, and started out in Manual mode. It shot up like a rocket and I had a heck of a time getting it under enough control that I could switch it into the GPS mode. Anyway, it certainly doesn't take much power to hover, and I think that might be a contributory factor in the crash.

I've had the same sort of problem, not being able to dial out the wobbles, with the new F450/Naza setup I just recently got in the air. For this I'm using the AKE 12A ESCs and motors that came with my XA Hexa kit, but I'm running them on 4s, and using Graupner 11x5 props. Again, can't seem to adjust the gains to where I can get it to stop wobbling, especially on descent. No crashes, though, but it's only been two flights. I should, at a minimum, be using 10" props, I think, but I don't have any 10x5 Graupners. Before, with my Gaui and VC-450 setups, I found that the GWS 9x5x3 props, when properly balanced, had less vibrations than the "standard" 10x5 props that CNC sells, but they are a real bitch to balance. Anyway, I've just replaced the 11x5 Graupners on the F450, so I will give that a "whirl".

-- Gary
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Old Jan 07, 2012, 01:49 PM
Who dares wins
Deutschland, HE, Nidderau
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Originally Posted by GGoodrum View Post
The second problem I have is that the 70-degree cutoff is only supposed to happen when the throttle was also less than 10%. This part I'm just not sure about.
According to the manual, its an logical "AND" condition when in "intelligent mode"

Page 17 Paragraph 2d "The slope angle of multi-rotor is over 70° and throttle stick under 10%."

But I have no clue what happens if the WKM not in "intelligent mode" but in a failsafe condition, landed and the slope angle is over 70°.

Learning to play the piano is easier then to remind all combinations for stopping the motor now ;-)

Bernd
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Old Jan 07, 2012, 01:57 PM
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If you choose "intelligent" mode on motor STOP, the 10% throttle down will not work!!

In my opinion maybe this is better to use.
But if the copter tilt on one side, and motor does not stop. result can be 2-3 esc burned out?
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Old Jan 07, 2012, 02:04 PM
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Originally Posted by freebyte View Post
According to the manual, its an logical "AND" condition when in "intelligent mode"

Page 17 Paragraph 2d "The slope angle of multi-rotor is over 70° and throttle stick under 10%."

Learing to play the piano is easier then to remind all combinations for stopping the motor now ;-)

Bernd
Yes, and that's the rub. I don't think I had the throttle "stick" under 10%. If I had been in Manual mode, however, it might well have been that if it hovers at only about 25-30%, I might have had to have the throttle under 10%, in order to get it down. The question is, what is the 70-degree cutoff function looking at, in it's logical "AND" decision, the position of the stick, or the actual percentage of the throttle signal being sent to the ESCs? It should be the former, but the evidence appears to be pointing to the latter.

-- Gary
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Old Jan 07, 2012, 02:09 PM
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Originally Posted by liteglow View Post
If you choose "intelligent" mode on motor STOP, the 10% throttle down will not work!!

In my opinion maybe this is better to use.
But if the copter tilt on one side, and motor does not stop. result can be 2-3 esc burned out?
Mine was in the Intelligent mode, and I can verify that while on the ground, it will not shut down when the throttle is under 10%. I either have to wait three seconds, or do the de-arming procedure, which is what I normally do. It has been my experience, however, that the 70-degree/10% cutoff logic works independent of whether or not you are in the Intelligent or Immediate mode.
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Old Jan 07, 2012, 02:10 PM
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Originally Posted by redridinghood View Post
I see no flashes though. But you must be right
Have a look at 1:24 ............
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Old Jan 07, 2012, 02:10 PM
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I have disablet AVG antivirus, and now windows give a message like att.
Is it possible to use GS on windows7/64bit as I have?
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Old Jan 07, 2012, 02:16 PM
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I have WIN7 64bit, but I only have the assistant software.

Dronenor: er du registrert pĺ fpv.no ?
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Old Jan 07, 2012, 02:18 PM
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ja liteglow, er aiha der
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Old Jan 07, 2012, 02:20 PM
Who dares wins
Deutschland, HE, Nidderau
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Originally Posted by GGoodrum View Post
Yes, and that's the rub. I don't think I had the throttle "stick" under 10%.
I just tried out what "10%" on my DX8 means (tried it with a mSR mini-helicopter): its just a little bit above zero. My DX8 creates a beep around 10% because that triggers the stopwatch for the 15min "motor on" count down.

Even during the wildest maneuvers my stick didn't went below the magical 10% barrier.

So I agree to you.

Bernd
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Old Jan 07, 2012, 02:30 PM
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nice trick with the counter
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Old Jan 07, 2012, 02:31 PM
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Originally Posted by Dronenor View Post
I have disablet AVG antivirus, and now windows give a message like att.
Is it possible to use GS on windows7/64bit as I have?
The ground station manual says win7, 32 bit only.
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Old Jan 07, 2012, 02:35 PM
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Originally Posted by Buffythesaint View Post
The ground station manual says win7, 32 bit only.
Is it possible to instal as win7/32bit?
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