Crash, crash, crash

[aldorellibus]

Hi everyone,
here's my story :tennis::

one day I was happily flying my drone, an Y6 with Wookong M until during landing it was coming down pretty fast when, about 5 meters from ground, I increased the throttle to land softly but nothing happened and it crashed hard on the ground. Arms, Canon 10-22 and props broke. I thought it was normal because I flew for 7:30 instead of 7:00 and the batteries were almost empty (95%).

Ok, I fixed it, got new props and did another flight. I flew for 5 minutes well but then, during landing, it crashed again. The drone was descending in a straight line and again, at about 2 meters from the ground I gave FULL power to slow down the landing but nothing happened (only 5:08 min). Another lens and props broke.

After that flight I was almost sure that the batteries were causing problems. Got new ones and tonight I went flying again. It was a test flight so I kept it about 1 meter from the ground for about 6 minutes when it started to lose height, full throttle again but nothing happened. It crashed on soft grass. I immediately tested the batteries that were 96% at the begininning and they were only 15% after 6:00 minutes. This is not normal. I've done about 100 flights with the old batteries and always flown 7:00 minutes and the batteries were always about 20%/25%.

Does anyone have an idea of what could cause the problem? I've been noticing a blinking white light on the DJI.

Thank you very very much!!!

 

[Droider]

100 flights on battery packs are pushing it. When they are loaded they my not be able to discharge correctly. As soon as they have load taken off them they will show ok. 100 flights is a lot on lips. Do u use a independent cell monitoring alarm?

Intermittent white lights are pretty normal. I get them on all my WKM especially when I am flying them hard. if it is permeant flashing more white than anything else something is amiss and you should not fly until it is resolved. The full light flashing descriptions is in the manual.

The other possible cause could be overheated ESC's. Do you have any temperature telemetry?

Dave

 

[mailman35]

wow u are flying your packs to 5% left? you have killed the pack by treating it like this.

 

[aldorellibus]

Yes, you guys are right that's why I thought the cause of all the problems were the damaged batteries.
But tonight they were brand new batteries and it happened the same thing anyways, plus I've tested the old batteries with a "battery medic" tester and it sayd they were 15% even when the copter crashed a full throttle.

On an Y6 platform the pusher propeller should be on top or bottom?

 

[Kilby]

You probably shouldn't go below 20% on your batteries. It will damage them if so.

What C rating are they?

 

[KeithM]

You very likely got into what is known in aerodynamics as a "vortex ring state" It is a common phenomenon in helicopters and multi rotors are no different. Do a Google search for "settling with power" or "vortex ring state" and you can read a lot about it. Basically, when the machine descends vertically, it can get caught in its own downwash. Adding additional power, just make it descend faster until it hits the ground. The way to recover is to move laterally so as to fly out of the downwash vortex created by the props. Here's some more info on the subject: http://www.heli-chair.com/aerodynamics_104.html

 

[Droider]

http://www.heli-chair.com/aerodynamics_104.html

Good info.

On an Y6 platform the pusher propeller should be on top or bottom?

Bit late now.. it is fully explained in the manual.

Dave

 

[aldorellibus]

What kind of answer is Dave??? Do you think if I had a manual I would t have rode it?
If you don't wanna help just don't waste your time commenting, your reply is totally nonsense!

Thanks

 

[ksrimoungchanh]

keeping on a productive path, I agree with Kilby. I messed up 1 of my Lipos just trying to get a few more minutes out and it went down to 3.68 per cell.. now that battery is just not the same.

 

[aldorellibus]

If someone can tell me if the pusher props have to stay on top or bottom of the platform i'd really appreciate it. It's a big doubt that I mounted it upside down.

 

[ksrimoungchanh]

I think if you open up the WKM assistance in the motor mixer, you can mouse of the configuration. I don't have Y6 config I have both 6X and 6I now.. I can tell you by experience.

Hope someone can chime in.

KS

 

[Skysurf]

What kind of answer is Dave??? Do you think if I had a manual I would t have rode it?
If you don't wanna help just don't waste your time commenting, your reply is totally nonsense!

Thanks

Hi Paolo,

I don't think that Dave's answer is nonsense, you will find this information in the WKM manual or at least in the software.

The manual can be downloaded here and assistant software can be downloaded here (if I remember right you need version 1.26): http://www.dji-innovations.com/products/wookong-m/downloads/#

The pusher props should be mounted on the bottom three motors, with the text facing up.

Hope this helps.

Have a nice day!

/Jesper

 

[baltiggle]

Aerodynamically there should be no difference between a tractor and a pusher so long as the pitch is the same. Physically, the pusher may have been manufactured stronger because it is presumed tpo operate in greater turbulence. Short answer, the pusher goes on the bottom. (but if it was on "upside down" I doubt you would have gotten five meters off the ground)