Tell me how I crashed my mini

[ARCapslock]

I'm hopeful someone can tell me what mistake I made here, I was cruising around the beach on the 4th on a lake we were camping at. Was doing some high speed passes on sport mode, I made a 180 pivot from running at full speed, and began to move forward in the opposite direction as I lowered my altitude a bit and began to go forward again, drone seemed to just drop from about 20' while going forward about 10 MPH.

My homepoint was about 20' over the surface of the lake and I was flying the drone right at my original homepoint altitude, I wonder if this might have confused the drone.

I'l try to upload the video of crash and provide link in a bit.

Mini was recovered with only some grass stains.

 

[itsneedtokno]

This should be in "Crashes and Flyaways"


Sounds like "vector something or rather".
It's a term I've heard before (old problem with Phantoms if I'm not mistaken) but I can't remember the right words.

 

[ARCapslock]

This should be in "Crashes and Flyaways"


Sounds like "vector something or rather".
It's a term I've heard before (old problem with Phantoms if I'm not mistaken) but I can't remember the right words.

Sorry for the misplacement, should start a new thread over there?

 

[itsneedtokno]

Sorry for the misplacement, should start a new thread over there?

Either a mod will take care of it, or they will answer you here.

...but for next time. Of which there hopefully never is one lol

 

[ARCapslock]

Here's the video, gimbal seemed like it maxed out on that turn too.

 

[itsneedtokno]

The gimbal was likely maxed from the pitch angle, happens all the time when flying in sport mode.

I still think it was a downdraft thing, but I could be wrong.

Those props are very flexible and deform easily from what I've read on here. I don't know about at speed though.

 

[Starz]

What did you see that indicates a “downdraft”.

 

[rehkram]

Looks like the props stalled-out on the tight turn and lift disappeared, curse of the MM, I've done it myself.

Just another way to trigger the famous MM uncommanded descent. Not your mistake, the mistake is the design of the props. But we've done that topic to death already. Glad you got it back OK

 

[itsneedtokno]

What did you see that indicates a “downdraft”.

Vortex ring state - Wikipedia

en.wikipedia.org

this is what i meant

 

[sar104]

I'm hopeful someone can tell me what mistake I made here, I was cruising around the beach on the 4th on a lake we were camping at. Was doing some high speed passes on sport mode, I made a 180 pivot from running at full speed, and began to move forward in the opposite direction as I lowered my altitude a bit and began to go forward again, drone seemed to just drop from about 20' while going forward about 10 MPH.

My homepoint was about 20' over the surface of the lake and I was flying the drone right at my original homepoint altitude, I wonder if this might have confused the drone.

I'l try to upload the video of crash and provide link in a bit.

Mini was recovered with only some grass stains.

Looks like the well-known uncommanded descent, explained here:

Mavic Mini uncommanded descent tests

After a little experimentation I was able to replicate the uncommanded descent problem under 0400 firmware by loading the rear props for a few hours as might happen in the flymore case. The props did appear slightly flattened compared to the front props. The problem quickly manifested itself in...

mavicpilots.com

 

[rehkram]

I'm wondering if turning the MM right or turning it left might trigger a prop stall more easily.

I've noticed I naturally want to turn it right for a smoother quick turn, I've found turning it left can get 'interesting' and so tend to avoid it. Will have to experiment to confirm that though, should be fun.

 

[itsneedtokno]

When I turn really hard with my MA2 in sport mode, I get some camera shudder. No uncommanded descents though.

 

[Meta4]

Looks like the well-known uncommanded descent, explained here:

Throttle up, drone goes down.
It's just a good, old-fashioned uncommanded descent.
Firmware was still on 1.0.244 too.

 

[rehkram]

Prop stall. MM props can't handle the pressure you can put them under in a tight left turn. The revs going up is an attempt by the brain to compensate for loss of height but the plastic is too thin to deliver, in fact it probably makes matters much worse. IMHO

 

[Meta4]

Prop stall. MM props can't handle the pressure you can put them under in a tight left turn. The revs going up is an attempt by the brain to compensate for loss of height but the plastic is too thin to deliver, in fact it probably makes matters much worse. IMHO

If that was true, Mini's would be falling from the sky almost every flight.

 

[rehkram]

Not really. The video shows an edge case, low and fast with a hard left turn. Hey, I like to fly that way as well.

There are multiple cases that cause the loss of lift. The common factor in all of them are (or seem to be, to me) the props turning 'inside out' and the brain commanding more revs to compensate for loss of lift, which will never succeed due to material science. The motors should actually be slowing down so the aerofoils can revert. Whatever the eventual fix is, either the software needs some work, or the props need stiffening, or both.

 

[Meta4]

Whatever the eventual fix is, either the software needs some work, or the props need stiffening, or both.

Uncommanded descents have become very uncommon with current firmware.
But the Mini in this incident was running old firmware.

 

[rehkram]

Good point. I agree the previous firmware seems to have been more prone to this problem.

 

[dirkclod]

And another good reason to stay up to date on software/firmware
and yes I moved this as soon as a saw it posted.
Sorry can’t stay on 24/7.

 

[itsneedtokno]

And another good reason to stay up to date on software/firmware
and yes I moved this as soon as a saw it posted.
Sorry can’t stay on 24/7.

im on here way too much, but i enjoy it, and what else am i doing...

if im not flying, working, or editing, im here.