What just happened

[Jussi]

So after a very long and first ever multirotor build, my Tarot 650sport quadcopter it decides to crash for no apparent reason.

I was flying most of the day just fine, no problems whatsoever with the quad itself. The h3 3d gimbal on the other hand is another story. After 40+ minutes of flying (with a battery change in between) I let it hover for a bit. Then all of a sudden with no warning the thing just decides to flip. It's like the props on one side (couldn't tell if it was left or right) just went to max throttle or something. So here is my circumstance along with the equipment I was using.

1. I was flying at a glider field so there were at least 3 or 4 others but we were all spread out several hundred yards. In fact, I couldn't even see most of the operators because they were on the other side of a hill. But I could see their planes / copters. Could I have gotten interference from another pilot?

2. My h3 3d gimbal that I had just installed was acting up all day and was constantly twitching when the copter was running but worked great when it was stationary. ie no twitching when copter was on the ground and I moved the copter around to see the gimbal work.

3. Equipment
- Naza V2
-2.4ghz data link
-bluetooth ( I think the bt on my phone was still running becasue I had made some changes on the copters gains and forgot to turn it off)
-iosd mini

 

[Motopreserve]

Damn! Sorry to hear about the crash. Was there much damage?

I think you should have been fine with the proximity of the other pilots. I have flown at the fliers with several others on 2.4, and had no issues. These radios hop and typically don't have problems with multiple people on the same bands.

I also think I've left my Bluetooth connection on after tuning and not had issues - but I suppose that could cause some interference?

What is the 2.4 data link? Is it possible there is interference between that and radio signal?

 

[Jussi]

Both of the back booms and motor mounts were toast. Oh and the props of course. Fortunately the motor *seems* ok. I'll have to run it and see. I went ahead and ordered the replacement parts right now along with a couple of extra for future crashes and it was just under $100 with expedited shipping (coming from china). Luckily it landed on the back side away from the gopro (which I had borrowed). I would have felt horrible if I damaged the gopro. I will definitely be returning it and buying my own.


Not sure about the 2.4 Data link. I didn't even have the ground portion of the data link hooked up yet. I'm still waiting for a battery to power that part up.

I was looking online and it seems a few people have experienced and commented on the "naza death roll". I really hope this isn't a bug in the fc. I also saw a video of a similar crash and the pilot said he solved it by re-soldering the bullet connectors on the esc and motor. I may do that just to make sure I don't have a weak joint somewhere.

 

[Jussi]

Oh and the battery got damaged as well. At least the outer sleeve. No punctures though. Is it still useable? If so, what should I use to re-wrap it? Giant heat shrink?

 

[Motopreserve]

It does sound like possibly a motor or ESC stopped mid-flight. That would cause a flip like you described.

I also had it happen once when the cheap HK PDB crapped out and cut juice to some of the motors. Last time I went the $2 route with any electronics components

Make sure you check everything on the bench before sending it airborn again.

I think if the battery cells are not damaged, and no puffing is occurring, you could probably wrap it in shrink wrap.

 

[Jussi]

Any recommendations / procedures to determine that all the connections are solid?

 

[Motopreserve]

I would check them out visually when you solder the new parts. Then fire it up on the bench and put it through its paces (props off!!!!).

 

[jinly]

Any recommendations / procedures to determine that all the connections are solid?

Was this a Maiden Flight?..It sounds like one of your connections to the motor or esc was bad. I bet one of the motors quit and then the flip. I have the Ironman 650 and the iOSD Mini, along with the 2.4 ghz Datalink w/ BTU. I have flown numerous times with the Futaba radio (which has freq. hopping) so no issues. I did have a motor go out. Screws loosened on the motor mount it flipped also. In fact it fell 300 ft. out of the sky crashed through a Maple tree and landed in my woods. I located it and all that broke was the landing gear and the Gimbal carriage. I have sinced broken down the whole "rig" and rebuilt it into a X8 Octocopter. The redundancy does work . I removed two props and it still flew. Never again will I trust anything such as a bad connection or loose screws crash it. I would check not only the motor connections but also the esc connections too.

 

[Motopreserve]

Yep. Since you're going to be in there - check ALL connections. No need to get the motor connections perfect only to lose it again on some other missed connection. You're in there, check 'em all.

 

[Jussi]

Yah I think I will do a complete tear down and unsolder everything. Reassembly should be much faster now that I know what I'm doing (well somewhat anyways ) . My only fear is that that the problem wasn't mechanical and that there is a bug with the fc. I've read several posts and seen a few vids about the infamous naza "dead roll". In fact I posted the same question on another forum and got a couple responses of it probably being a naza dead roll. I can fix and verify the fix with a mechanical problem. Not really sure how to test if it's a defective fc without flying it.

Jinly, It was the first long flight. I have tested in my backyard but because of the space I mainly just went up, move around a bit and came back down. That day I went to a park that has a glider field and flew it for close to an 45 mins. I initially only had 1 battery so I flew it in the morning for 14 minutes or so. No problem. The 2 additional batteries I ordered came later in the day and I decided to go back. Flew the first of the 2 batteries for around 14 mins again. No problem. Changed batteries batteries and probably 10 mins into the flight I set the copter to hover and thing just decided to flip. So while technically it was the first prolonged maiden flight, I had in the air for around 40-50 mins. Not to mention the half a dozen or so short test flights. So if there was a mechanical problem, I would think I would have seen it before. But maybe a connection was weak and the longer test flight shook it loose.

It's kind of depressing because it a long time to assemble, not to mention the hours reading forums, and watching youtube videos. I've been working on it every night for last 2 weeks so I'm going to take a break until this weekend at least. Maybe a clear mind will help me see something I missed earlier.

Thanks for all the advice.

 

[Motopreserve]

There are many mentions of these flips. I don't think hey can all be written off - but I also think that many things get blamed on the FC before thorough investigation is done.

I've flown Naza's for many, many hours and not had any flip of death. I did however have one when the PDB sh*t the bed, so I'm always leery of skipping a good going-over of the electronics.

Cold solder points can come up 10 minutes or 10 years into their application.

When you say you put it into "hover," what do you mean?

 

[Jussi]

Center position on both sticks.

When you say you put it into "hover," what do you mean?

 

[Motopreserve]

In ATTI mode or GPS?

 

[Jussi]

I was switching back and forth because I wanted to get more comfortable flying in ATTI but I'm pretty sure it was in GPS because it was pretty steady and when I was on ATTI I would drift more.

 

[jinly]

Yah I think I will do a complete tear down and unsolder everything. Reassembly should be much faster now that I know what I'm doing (well somewhat anyways ) . My only fear is that that the problem wasn't mechanical and that there is a bug with the fc. I've read several posts and seen a few vids about the infamous naza "dead roll". In fact I posted the same question on another forum and got a couple responses of it probably being a naza dead roll. I can fix and verify the fix with a mechanical problem. Not really sure how to test if it's a defective fc without flying it.

Jinly, It was the first long flight. I have tested in my backyard but because of the space I mainly just went up, move around a bit and came back down. That day I went to a park that has a glider field and flew it for close to an 45 mins. I initially only had 1 battery so I flew it in the morning for 14 minutes or so. No problem. The 2 additional batteries I ordered came later in the day and I decided to go back. Flew the first of the 2 batteries for around 14 mins again. No problem. Changed batteries batteries and probably 10 mins into the flight I set the copter to hover and thing just decided to flip. So while technically it was the first prolonged maiden flight, I had in the air for around 40-50 mins. Not to mention the half a dozen or so short test flights. So if there was a mechanical problem, I would think I would have seen it before. But maybe a connection was weak and the longer test flight shook it loose.

It's kind of depressing because it a long time to assemble, not to mention the hours reading forums, and watching youtube videos. I've been working on it every night for last 2 weeks so I'm going to take a break until this weekend at least. Maybe a clear mind will help me see something I missed earlier.

Thanks for all the advice.

Good Luck, . You know I have read about the "Dead Roll' also. I have flown my Naza for almost two years without a flip. I have crashed it alot from just learning how to fly it and FPV flying, but never a complete flip. I think if you had a "lemon" Naza you would had other problems with the flight characteristics. Who knows...only way to know is to get it in the air. You are right it is disconcerting to wreck your craft that you have worked on for hours (days even), however , like you said you'll be rebuilding with experience now. I have three multicopters I have built over the years. I find it really relaxing and enjoyable to build or rebuild these crafts. At least for me it has. I'm always changing them. Fly On Brother!

 

[Jussi]

I find it really relaxing and enjoyable to build or rebuild these crafts. At least for me it has. I'm always changing them. Fly On Brother!

That's a good point. Maybe the 2nd time around it will be more relaxing since I'm not stressing out on what to do next or if I'm doing the current step correctly. It's probably like driving. When you first start out you're nervous and super cautious that you're doing everything correctly but after you've gotten experience it becomes 2nd nature and you just go into auto pilot. This time, since I know the steps, I an focus on my technique and make sure things like my soldering is solid.

 

[Dragonrider]

Has anything new been determined about flip or roll of death with A2? We just experienced this ourselves and all confidence in A2 is gone :-/ Any other recommended FC's? Wookong is old but seems to be extremely reliable?

Thank you,

 

[Bartman]

Oh and the battery got damaged as well. At least the outer sleeve. No punctures though. Is it still useable? If so, what should I use to re-wrap it? Giant heat shrink?

if the end of that battery got crunched it should be disabled (I prefer to slice the edges of the cells and soak it in salt water overnight) and disposed of.

 

[fengshuidrone]

Has anything new been determined about flip or roll of death with A2? We just experienced this ourselves and all confidence in A2 is gone :-/ Any other recommended FC's? Wookong is old but seems to be extremely reliable?

Thank you,

Well, I'm biased against any FC that costs over $80.00 so I probably shouldn't even mention the fact that my multiwii can control an octo, has waypoint GPS, and is highly customizable to fit ones needs. All you gotta do is be able to figure it out and tune it. I would put my well tuned Multiwii Pro up against any $1000.00 + FC and probably outdo it as well. I would trust my $10,000.00 cam with it, if I had a $10,000.00 cam, but I don't.

 

[Bartman]

the flip of death stuff was common early on in the development of NAZA-M V1, I haven't really heard much about it with the V2. The A2 has been dogged by issues, particularly with the features that rely on GPS (which is only like everything!) but the new GPS is supposed ot make it all better. i haven't replaced mine yet, at $180 or so I'm not happy