Mikrokopter First big crash and need help for analysing the log

[ovdt]

Hello everyone,

I had my first big crash today. I was flying my droidworx AD6-HL for a couple of times. and I was quite confident with controlling it.

I changed the batteries with the new recharged one and went out to fly it again.

There was no wind outside. After landing off, it suddenly rolled left and descended very fast. I couldn't stabilize it with roll right stick movement.

EDIT: It seems Navictrl didn't log the last flight

The damage so far:
* Two broken arms
* 2 broken props
* HexaXL distribution board is slightly damaged, will need to replace it. And there might be a damage on two BL Ctrls.

 

[ovdt]

I did first inspection and there was no weak solder etc.

Other notes:

* Lipo is Turnigy 4s 5000 mAh. And I've read the V just now and it's at 16.2V.
* I didn't make any software adjustments after my last succesful flight.

 

[Droider]

I hate reading these posts.. What FC/Nav firmware you on?


Grrrrr. You ran out of power by the looks of the log...


Really sorry to here what happened.

 

[Droider]

You were flying on under voltage from 807 secs in..

you just cant push lipos that far buddy.. sorry but first glance looks like you need some alarms you can here or just limit time to 8mins on a 5000 cell depending on what your flying conditions are..

Still gutted for you

Dave

 

[ovdt]

Hello Dave , thank you buddy.

I just realized it, I can't seem to find the log for the latest flight. The one I attached is from the previous flight. I got the alarm set, so I landed succesfuly that time.

FC is on 0.84a
And NaviCtrl 2.0 is on 0.24e software.


Is there specific reason that NaviCtrl doesn't log the flight?

 

[Droider]

SD card full or not in correct.. I am very suspisious of the affects of the SD cards. When I origionally tried a 64mb card the bird flew fine until about 6 mins in then it would start going berserk.. I have videos posted on youtube.. It amy be your card was full and in trying to write to the card was to much for the FC..

Have to checked your card for errors and that its a good card and not corrupted

DAve

 

[Crash]

Well if it's not the battery there are a few other things it could be.

Check the gyros against the ACC in the scope. The lines should follow each other pretty closely when the MK it tilted and rolled.

What parts and firmware are on the MK?

 

[RBlax]

I do not have anything valuable to add, but Godspeed getting back up and running. I will be watching this thread to learn and I appreciate your willingness to share. This honestly was a nice jolt for me to take even more time in building and listening to everything you guys say! I appreciate all the help so far and I hope you figure this crap out! Keep us posted man.

 

[Quad_Addict]

describes a motor going out as well. have you tested the motors in tools output test? and scope?

 

[ovdt]

If I had the flight log, I think things would be lot easier I'm using Kingston 2GB SD card, which is just empty and writable.

Crash: I'm gonna check the gyros after rebuilding the craft. I'm gonna need 2 booms and motor mounting plates. Once I get them, I'm ready to go and also check the gyros.

MK consists of:

Flight Ctrl ME 2.1 (0.84a)
NaviCtrl 2.0 (0.24e)
GPS 2.0
Axi 2817/22 motors
Bl-Ctrl 2.0

I said there was no solder problem but, I came acrros a little problem while inspecting deeper. On one of the Bl-Ctrl (which is controlling motor #3), one of the cable solders was very weak so I could seperate it with my own hand without any force.

Here is the diagram:

Let's assume the problem is with the solder of motor cables:

If motor #3 goes down, which direction the MK would fly? Will it lean forward left or backwards right? If the craft moves forward left, then the problem source is discovered.

I'm still wondering why flight log didn't recorded though.

For rebuilding the Droidworx AD6HL frame:

* Landing gear uses 7mm CF tubes (37 cm long for landing skid, 19 cm for mounting the landing plates together) . Each 37 cm Droidworx CF tube costs 25$. My landing gear looks perfect when looked from outside but I can see the cracks when looked closer. So I'm going to change them.

Instead purchasing these, I bought 8mm aliminium tube (2 meter long, and 1mm wall thickness). It's 4$. I cut them and they fit perfectly. Aliminum ones are 1,5 gr heavier than the each CF ones. So no problem.

* Booms: 355 mm CF booms. I'm going to buy this from Droidworx just for once (45$). But for the next crash I'm preparing aliminium alloy versions. 5 meter for 15$.

* I have to buy some small parts like gear rail bracket which I can't manufacture by myself right now.

* I need to change a motor mount adaptor which is broken. The biggest problem with round tubes is the motor mount adaptors. aglhobbies.com has some delrin blocks for round tubes but they are for 12 mm round tubes. So I need to find a way to fit the motors on the round tubes without paying 75$.

Thanks for the ideas and help guys, I'm gonna keep posted with pictures.

 

[Droider]

How many gear rail brackets do you need.. I make um out of aluminium.. I have two sat in my sparesbox if you need um..

Dave

 

[DroneBuilder]

Another troubleshooting item to check on is whether one of the ribbon cables from the FC to the Nav came loose. Seems to be a common problem that creates uncommon errors each time.

 

[ovdt]

Thank you Dave, I'm sending you a PM.

DroneBuilder, thanks for the tip. The ribbon cables were solid.

The only question I have right now is, when the motor #3 goes down, to which direction will the craft tends to fly?

 

[Droider]

The only question I have right now is, when the motor #3 goes down, to which direction will the craft tends to fly?

Not sure but if 6 & 5 slowed down and 2 and 4 speeded up forward and left.. good question!

Have you double checked you SD card for the flight log?
DAve

 

[Droider]

Gear rails brackets I made out of some aluminium angle

 

[ovdt]

Dave, they look great. I wonder how you cut them perfectly

Droidworx's standart gear rail brackets are born to be broken

 

[Droider]

Dave, they look great. I wonder how you cut them perfectly

Droidworx's standart gear rail brackets are born to be broken

Packet on way.. could not find the ones shown in picture.. I think that are at my work place but sent two others

Dave

 

[ovdt]

Thank you very much Dave.

I figured out the craft would move forward left if the motor #3 goes down in a hexa setup.

Weak solder seems to be the problem considering this finding.