I crashed after clipping the branches of a tree. This ended up cutting one of my receiver antennas. At first I did not notice the problem and tried to fly again. It was acting strange and would burst up higher without any stick input. I was able to disarm it without any issues, but it fell about 10-15 feet to the ground. I tried it again and this time it acted like a failsafe and shut itself off and fell about 10 feet.

I ordered a replacement antenna and thought that would be the fix. After replacing the antenna, I went outside and started to hover, once I got about 10 feet in the air it started to act strange again and went up about another 5 feet. Again I hit the disarm switch and it fell to the ground.

Model Flywoo explorer LR
Radio radiomaster TX16
Reciever XM÷

This was flying fine before this last crash.

Any help is apritiated.

Ed

do you get some osd warnings? can you rewatch the dvr?

it sounds like you have a flyaway, when it "acted like a failsafe" there might be runaway protection jumping in. you would get "runaway" as osd warning displayed.

things i would check;
-is there anything loosen, can cause vibrations? any screws loosen?
-is the frame still rigid or is there some delaminated carbon? bend the carbon arms an look for differences in stiffness between the arms

vibrations a screw or some delaminated carbon can cause it to runaway.

It could also be a bad gyro causing the pid controller to over react and cause a runaway.

I went over all the screws and made sure they were tight. I had removed a plate on top of the stack to check the wires and found that three of the small washers fell out. I found them on my black bench(the washers are also black) put them on and tightened the stack down. Went back outside for another test and it still behaves the same. 

Hooked it up to betaflight and the sensors show activity for both the gyroscop and accelerometer.

Afraid to put the goggles on until I get the hover issue resolved. If it would help I could DVR another attempt to hover, but I feel like I might be pushing my luck and the next time I try to fly it will decide to leave me for good.

Thanks,
Ed

(20-Jul-2021, 02:55 PM)Soniccj7 Wrote: I went over all the screws and made sure they were tight. I had removed a plate on top of the stack to check the wires and found that three of the small washers fell out. I found them on my black bench(the washers are also black) put them on and tightened the stack down. Went back outside for another test and it still behaves the same. 

Hooked it up to betaflight and the sensors show activity for both the gyroscop and accelerometer.

Afraid to put the goggles on until I get the hover issue resolved. If it would help I could DVR another attempt to hover, but I feel like I might be pushing my luck and the next time I try to fly it will decide to leave me for good.

Thanks,
Ed

in betaflight, when you say you see activity for the gyroscope, is it the correct orientation? when you dip the front of the quad does the front in the graphic dip ?

If it was flying fine before the crash then it seems like it must be something physical on the quad itself. First thing I always look for is any cracks in the frame or delaminating carbon layers, especially in the arms. Then I check that everything is mounted securely and nothing worked itself loose in the crash, especially the FC/stack itself.

I look at these 2 things first, because all of the quads actions are based off of the gyro data it's using, so it the stack is wobbling around, or a cracked arm is, then the gyro is going to be getting a lot of strange readings and it is going to try to compensate for them.

If there is no damage to the frame, and the stack and everything else is all secured as it should be, then that is a very strange problem. Only thing I could think of then would be possibly trying a different flight controller, to see if maybe something on the FC itself is broken.

(20-Jul-2021, 04:50 PM)LostDharma Wrote: in betaflight, when you say you see activity for the gyroscope, is it the correct orientation? when you dip the front of the quad does the front in the graphic dip ?

Yes, the orientation of the quad matches the onscreen display.

(20-Jul-2021, 05:02 PM)MrSolo Wrote: If it was flying fine before the crash then it seems like it must be something physical on the quad itself.  First thing I always look for is any cracks in the frame or delaminating carbon layers, especially in the arms. Then I check that everything is mounted securely and nothing worked itself loose in the crash, especially the FC/stack itself.

I look at these 2 things first, because all of the quads actions are based off of the gyro data it's using, so it the stack is wobbling around, or a cracked arm is, then the gyro is going to be getting a lot of strange readings and it is going to try to compensate for them.

If there is no damage to the frame, and the stack and everything else is all secured as it should be, then that is a very strange problem. Only thing I could think of then would be possibly trying a different flight controller, to see if maybe something on the FC itself is broken.

I don't see any issues with the frame or anything else. I made sure everything was tight and no wires are missing.

I don't have another flight controller available at the moment to test. If that is the only solution I will look into purchasing a new FC, but not sure I want to buy the same one, if they can break this easily.

you should check all the voltages on the board and spin the motors up in betaflight. I'm no expert but would flashing the FC back to default help ? Just in case there is a strange setting like GPS recovery mode setup or something

(21-Jul-2021, 01:28 PM)LostDharma Wrote: you should check all the voltages on the board and spin the motors up in betaflight. I'm no expert but would flashing the FC back to default help ? Just in case there is a strange setting like GPS recovery mode setup or something

I will try flashing the firmware tonight.
 
Quick test lastnight on the bench(no props) I armed the quad and gave a small amount of throttle, when I went back down to 0 throttle the motors speed increased. I did not have the goggles connected at the time, so I am not sure if it was reporting any warning.

I will update this thread after I try flashing the firmware.

Thanks

When you try to run the quad with no props on the motors will do strange things. This is because the flight controller is expecting to be able to make adjustments using the props/motors, but there are no props so when it spins up a motor faster it doesn't do anything. This freaks the quad out because it isn't getting the changes in attitude it is expecting, but it will keep on trying.

This will often result in motors spinning up very fast all of a sudden because it thinks it needs to spin that prop faster to get it to do what it wants. But no matter how fast it spins it can't make the necessary adjustments without props on.

Flashed the firmware, Used an older config to restore from, Still seeing the same issue. This time I started the DVR on my goggles and watched the footage after the failed flight, the warning was 'runaway'.

Aside from part swapping, is there anything left to do?

Not looking forward to soldering all those wires..

Thanks,
Ed

I would like to thank everyone for their help on my issue these past couple days. This is the beginner area, so when I say what the issue was please go easy on me .

I found a video from JB about runaway mode. I checked everything in the video on betaflight, then decided to take a closer look at my props. one of my front props, while having the blade facing the correct way did not match the curve of the other blade. I pulled it off and flipped it over then went out side for one more flight(always just one more flight test). Stood back, hit the arm and was ready to kill the power when something went wrong, but this time nothing went wrong, it flew!!!

Guessing along the way with all the other work I fixed the original issue, but caused a new issue when I put the prop on upside down. 

Again thanks to everyone who helped me. 

Ed

nice you will get air-pleasure soon :-)

Great stuff ! ....... a problem solved is a problem solved, all good.