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Old Dec 08, 2014, 07:25 PM
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DJI A2 - version 1.4 - Loosing altitude while flying forward

anyone know why I would be loosing altitude when flying straight forward and back.

I'm flying a X8 Coaxial and I loose a substantial amount of altitude when flying forward and have to pull up before hitting the ground. I start at 15 feet and fly forward and it gets down to 5 feet which is loosing 10 feet in altitude.
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Old Dec 08, 2014, 10:21 PM
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What is your AUW? Have you tried to take off in Manual? What is your hover point, 50%? If higher than that then the controller may be struggling to maintain altitude while also doing forward flight. You many not have enough overhead to compensate.
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Old Dec 08, 2014, 11:30 PM
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I have to rigs and they are both showing this behaviour.

One flying at 7kg AUW without camera payload and 13kg with camera.
Both with and without show this drop in altitude behaviour.

Hover is at 50%

Flying side to side it keeps it altitude and it only on flying forward and backward.
Its seems like a bug as I never had this on 1.3

On my second rig the AUW is 8kg without camera and 14kg with camera.
Again this loosing of altitude happens regardless of payload and only on flying forward.

Both have brand new A2 controllers with 1.4 software. One is flying 18" props and other 26"

Just seems really strange that I have this behaviour on two separate machines and its really bad, like "if you don't compensate you'll crash to the ground" bad

I used to have solid flight and now have to really compensate for this bug.
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Old Dec 08, 2014, 11:31 PM
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I've taken off in manual but it doesn't effect take off. Only flying forward and back.
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Old Dec 09, 2014, 12:38 AM
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Have you tried raising your vertical gain?
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Old Dec 09, 2014, 01:38 AM
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Yes I have tried raising the vertical gain but only by 50 (was at 100 and took it to 150 and saw no difference).

Do you know where i can find more information on the vertical gain and how the setting effects flight?

I see it has a base starting point of 100 and goes up to 500 but don't know what the numbers mean to flight and how a larger number would effect it.
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Old Dec 09, 2014, 08:58 PM
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Ed, can you please give us some tips on adjusting the Vertical Gain on the new A2 software.

There looks to be adjustments for Vertical I and Vertical V Damping... what these mean and how the range 0 - 500% works is a mystery.
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Old Dec 09, 2014, 10:16 PM
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Quote:
Originally Posted by roryhinds View Post
Ed, can you please give us some tips on adjusting the Vertical Gain on the new A2 software.

There looks to be adjustments for Vertical I and Vertical V Damping... what these mean and how the range 0 - 500% works is a mystery.
All I can tell you is what I have been told by DJI on the Advanced gain adjustments. "You don't want to mess with them." I have never done so, so I don't know. I can ask engineering for an explanation.
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Old Dec 09, 2014, 10:38 PM
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Thanks Ed, please ask.

I really need to fix this loose of altitude as it really is going to crash the rig and pretty crazy its doing it in the first place.
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Old Dec 09, 2014, 10:50 PM
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I found in my use of the A2s in quad, flat 6 and Y6 configurations that the altitude hold was right on. I never tried X8 but the other modes I tried it on it was right on. It may hove gone up or down 2' at most when traveling forward from a stop.

I found that the A2 does a better job holding altitude than the Nazas. The Naza needs to have the vertical gain a little higher than the other gains for a given configuration.

I would pull the controller off and put it on a simple aircraft like a quad and see if it works on that. It's time to do some trouble shooting.
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Old Dec 09, 2014, 10:58 PM
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Yes I'll have to touble shoot but until then I have to fly and run my business.

This loosing altitude things is so bad that I can start at 15 feet and hover fine, I can move left to right and still stay at 15 feet but when I move forward the rig drops down so badly it will almost hit the ground... well it would if I don't pull up.

Pretty crazy really and pretty hard to fly this way.
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Old Dec 09, 2014, 10:59 PM
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and this is doing it on 2 completely separate machines with different motors, props sizes and ESC but the same FC... one would think its the FC and its settings wouldn't you?
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Old Dec 09, 2014, 11:19 PM
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Are both aircraft X8? You can also go higher than 150 on the vert gain for testing. Is the problem worse when you increase the all up weight?
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Old Dec 09, 2014, 11:21 PM
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I don't think it is the controller. I think it has to do with your setup.
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Old Dec 09, 2014, 11:26 PM
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yes both are X8.
How much higher than 150 on the vert gain?
Do I adjust both I and V. Damping on the vertical gains?

Weight seems to have no impact on the issue. I fly with no weight and with weight and the issue is the same.
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