HELP! MAVIC crashes when I try to take off

Faith_Granger · Sep 8, 2017

Have a 360 VR drone shoot in 5 days and experiencing systematic crashes at take off!!!

1. Drone takes off just fine from the ground (every single time)
2. Once drone is on a U shape platform to elevate it from the ground, it crashes (we are going to attach a gear 360 VR camera to it for this big VR shoot coming up next week, and will need some sort of U shape platform to elevate the MAVIC from the ground at take off, since camera will be attached to the Mavic belly, upside down, preventing the MAVIC front and rear "feet" to reach the ground)

Pattern is as follows: I initiate take off by pulling left lever up - then - propellers speed up - then - drone rear starts to lift up the ground - then - drone becomes slightly "nose down" in its attempt to lift off - then - propellers suddenly stop - then - drone crashes nose down - then - I get an error message on my app that read "props and motor failure. check props and motor". The entire above process only takes 3 seconds.

But if I take the drone "as is" after that crash and put it on the ground it takes off just fine (so basically there is no bad propeller or motor problem). It only crashes once on a 'platform'.

I have tried every scenario possible, including using different objects as a platform, deactivating sensors, protection landing, obstacle avoidance, and anything else I could deactivate, but nothing changed the sad outcome: CRASH CRASH CRASH.

Does anyone else here fly with a Mavic pro with a 360 gear Samsung camera using the professionally build bracket depicted here: DJi Mavic Bottom Mount With GoPro connector & came by jeanmariecannie on Shapeways

and if so can you please help me figure out how to solve my problem? My shoot is in 5 days :/ ....

MrsTreat · Sep 8, 2017

Remember - the blades point at the sky.

spindlejockey · Sep 8, 2017

Hope you find a solution, I fly with a I phone.

LuvMyTJ · Sep 8, 2017

Possibly the bottom sensors mis-reading the surface? Have you tried with them all off?
Could always hand launch & catch.

MChittum · Sep 8, 2017

Is the platform made of metal?

Jacknet007 · Sep 8, 2017

I had out clip on lights on the front legs and another underneath right behind the Gimbal . It would always fail to take off by going nose down due to too much weight in the front. On a normal take off the back end picks up first so this must make it tip over if there is too much weight in the front. Maybe hand launch and hand catch would be worth a try.

Faith_Granger · Sep 9, 2017

HERE IS MY REPLY TO ALL ABOVE POSTS:

1. Blades point to the sky?? No idea what you mean by that.
2. Platform not made of metal
3. As I said I did try to deactivate all sensors, same outcome.
4. Weight issue: That was my first thought too, so to test this I made a mock camera with a tiny sock and weights inside, to measure and weigh the same as gear 360. I placed the sock on same bracket in same spot as the real camera would go. Drone was placed on the ground, sock sideways so it would not interfere with drone legs touching the ground. Drone took off 100% of the time impeccably, no crash. But as soon as I placed the SAME set-up (drone + bracket + sock + weights) on platforms, it crashed 90% of the time. After each crash I placed it on the ground immediately and did another take off, and the drone took off perfectly. WHAT THE HECK????
5. Hand take off / landing. I have only flown a drone only twice. Second time I flew it, I performed several hand landings, no problem. However today I tried to do a hand take off with the camera attached to the drone and almost got a heart attack. because it is behaving so erratically at take off, I cannot trust it and I like all 10 of my fingers

would hate to part with them ....

Faith_Granger · Sep 9, 2017

I wonder... Should I angle the platform so that the drone sits on it with nose slightly up to compensate for the nose down that will occur once I initiate take off sequence? Could this work?

Faith_Granger · Sep 9, 2017

Masheen said:
Tried turning off any network protocols like BT on the cam?

I forgot to answer your post.... Since the crash also occurs with the mock 'camera' (sock and weights) described above, I rule out that a network protocole on the camera is causing the crash. Cause socks don't have network protocole (as of yet LOL)

Oh, and... What is "BT"??

4wd · Sep 9, 2017

Faith_Granger said:
Oh, and... What is "BT"??

Blue Tooth, it won't be that though.
Your best option would be hand launch and catch.
The VPS (downward sensors) want turning off if you have anything unusual below.

geigy · Sep 9, 2017

I suspect a VLS problem of some sort - anything underneath the Mavic can cause problems with take-off and even subsequent flight if attached. I suggest uploading the log files, and providing a photo of the u shaped platform. Maybe one of us can figure out what is happening.

Hand launch and catch is not really that hard. Repetitious, I know, but I have to say make sure VLS is turned off.

Kilrah · Sep 9, 2017

I would suspect the weight, with the sock from the ground the extra weight comes gradually, while when hung it's there from the start. The Mavic might have a protection system that shuts down if no lift off is detected above a certain power level, the sock letting it move enough to detect successful takeoff.

Hand launch and a little "help" from the hand could solve it... but I wouldn't expect it to work every time.

Some people have already done that successfully, so it would be a good idea to see how they did (platform vs. hand launch).
If they used a platform it's possible the shutdown was added in a more recent firmware version, in which case it could be useful to try older versions.

Seeing people routinely fly with extra batteries / weight I would favor the "new firmware introducing that" scenario.

mavic53 · Sep 9, 2017

Ask this chap

Abbo69 · Sep 10, 2017

If the MP has no problems with the mock/sock camera without the 'U' shape platform. How about trying a flat platform (plywood) with a suitable sized hole just big enough to allow the 360 through? Therefore allowing downward sensors to see flat platform.[emoji848]

Mako79 · Sep 10, 2017

Switch to sports mode and take off. Sports turns off all OA systems.

Faith_Granger · Sep 15, 2017

Kilrah I think you nailed it. I was finally able to take off by compensating the camera weight by the angle of the drone when it's sitting on the platform prior to take off. Once I reached a certain stationary "nose up" angle on my ramps, the drone was able to lift off. there is a little nose down struggle at first but the drone is able to overcome the weight handicap and after a slight nose down" initial tendency it levels off and shoots straight up in the air

... i used smooth ramps sp the drone glides up the ramp during its initial struggle and then he's happy as a clam and takes off

...

I also agree that it feels to me that the Mavic was shutting down itself because it sensed something was going wrong at take off, as a safeguard to avoid being up in the air and THEN crashing because something is wrong. better to crash when you are only a few inches off the ground then when you are 20 feet up, right? Smart, but I wish it would have asked my my opinion nevertheless

.

For good measure, my sponsor has sent me a second Mavic which I am going to test and see if I get the same behavior. maybe the unit I have is defective? I'll post my findings here, in the hopes it might help someone else in the future.

QUOTE="Kilrah, post: 294749, member: 2265"]I would suspect the weight, with the sock from the ground the extra weight comes gradually, while when hung it's there from the start. The Mavic might have a protection system that shuts down if no lift off is detected above a certain power level, the sock letting it move enough to detect successful takeoff.

Hand launch and a little "help" from the hand could solve it... but I wouldn't expect it to work every time.

Some people have already done that successfully, so it would be a good idea to see how they did (platform vs. hand launch).
If they used a platform it's possible the shutdown was added in a more recent firmware version, in which case it could be useful to try older versions.

Seeing people routinely fly with extra batteries / weight I would favor the "new firmware introducing that" scenario.[/QUOTE]

geigy · Sep 15, 2017

I wonder too if it would take off with less forward tilt if you moved the attachment point of the payload back a bit, say 1 or 2 cm.

CamoGreg · Sep 15, 2017

Did't read the full post but ask Jon, he is on the forum and he has a great YouTube channel

Shoruk3n · Sep 21, 2017

This attachment looks as if it would place the center of gravity too far forward to me. I believe your description of the the crash fits this explanation as well.

Dragonfly · Sep 22, 2017

Also do not use auto takeoff but manual takeoff only. Auto will sense the unbalanced weight to power ratio and shut down Mavic while in manuel take off you can apply power as needed to attain lift over weight.