motors revving up while idling... sometimes

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so sometimes if I land and still have motors idling, sometimes... they will gradually get back up to speed and if left long enough take off... I need to either shut off motors or hold down throttle a little to keep it from revving back up. When it happens its a slow gradual increase but yeah, they do eventully go fast enough to take off.

As I said, doesn't happen all the time... can't figure out under what conditions it happens... Not to much of a problem as I never leave it unattended or take my eyes off it when its on the ground and motors are running.

Running newest firmware, its 3-4 weeks old.. Always done this since I have had it.. well the times it does actually do it.

Any one have the same issue ??
 
I have 2 Phantoms and it happens on occasion on both machines for reasons unknown.
 
No fix or error on operators part.

Do not land and then allow to idle.
Many have had tip overs with damaged props, motors, and ESCs as a result.
 
I have observed this exact behavior 3 or 4 times in the course of 2 months.
In my case not all engines are revving at the same speed. The result is that it causes it to tip over. I always caught it on time and was able to force the motors off.
Not sure why this is happening, but maybe it has to do with the perceived altitude of the bird when it is on the ground.
 
It will happen if you land and don't shut off the motors because it is still trying to hold position (GPS mode) and altitude (GPS and Atti mode) while the sticks are in center.
Also will happen if you start your motors, rev them up but don't take off and return your sticks to center, same as above it is still trying to hold position and alt.
 
^^ Yeah that makes sense, all though I would of thought it should constantly do it.. but yeah definetly sounds like what it might be doing.

Anyways I have the prop guards off so I turn off motors straight away now.

Just in regards to tip overs while we are on the subject, now I have the prop guards off I am abit worried.... would getting those extra long landing skids help ? long horizontaly (not longer as in higher).. you know the ones which cover more of the ground, kind of like long skies ?
 
I think this behavior may be a real bug in the firmware in one of their state machines. If you land the motors go to idle. This means it knows it has landed because it never goes to idle on its own while in the air. When it enters this state it should then immediately enter the same state it is in when you start the motors from motors off. I can't think of any reason why it wouldn't want to do this. Anyone else?
 
Maybe a 'hand catcher' can test it.

Catch land at your normal height above the ground, once idle is established (as if on ground) lower the a/c and see if the motors spin up in response.
 
Instead of different landing gear , how about practicing landings! You need to shut it down as soon as it's on the ground. You will get used to the ground effect from the prop wash. Just practice.
 
Most likely barometer is seeing slight drop in altitude even though it is actually stationary on ground.

And yes if when I hand catch, and mind fart not keeping it at height while doing the full throttle down, motors do rev up.
 

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