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Unbelievable

Joined
Feb 10, 2019
Messages
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Age
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So I just got the 4k yesterday and made sure all firmware was up to date and calibrated everything. Took it out for first flight today. Took off and hovered at about 10 feet for a couple minutes and all good. Climbed and started out, it gets to about 40 feet and the thing throws a prop, flips over and crashes upside down! Im 100% sure they were tightened snug. As a rookie I'm at a loss. Looks like a new body, gimbal mount and learning to work on it is in my future.
 
Did you purchase a new or used aircraft?

Was the wrench to hold the motor still during prop attachment used?

We’re all the O-rings in place and in good condition that cushion the prop and motor hub interface?

A little late now, but it is always a good idea to get a few flights in without the camera attached to test the aircraft and how it handles.
 
Purchased new. I used the wrench to tighten and double-checked them to make sure they weren't over tightened. All the o rings look like they are in good shape as well.
 
Did the prop back out or break up?
 
Loosing an OEM prop on the Q500 is rare when they are properly tightened. I have never used the tool to tighten the props. I just spin them on until it feels snug, hold the motor with one hand and turn the prop with the other until if feels tight. At that point the oring should be compressed and hold the prop in place. Props are lost when one of the motors "brakes" during flight which is associated with stopping at the end of a maneuver or when landing.

Inspect the motor shafts to determine the length of the threads. They should all be similar to the pic below. Do the same with the props. There have been rare occurrences of shallow thread depth which prevents the prop from snugging down against the oring.

14730
 
Shafts look fine as well as the threads. Tightened up spare prop on the motor the prop came off and it snugged up. The motor that lost the prop spins freely with no binding. Im ?% on the props being tight. I do have that buzzard luck though so if a one in a million failure were to happen it would happen to me. On further inspection looks like it might be just the body and a wire to the cgo3 that was pulled loose. I thought gimbal mount but looks like the rubber dampers just need put back in?
 
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Here it is. Goes to board slot marked PWM
 

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Also while hooked up to gui I'm getting this with numbers bouncing around
Accelerometer x0.002 y0.003 z1.000 magnitude 1.000
Gyrox0.03 to -0.03 y-.03 to 0.13 z.01 to -.07
Orientation roll .03 pitch -.056 and the strange one yaw -108
Everything has check marks and engine diagram is all green as well
Does anything sound abnormal? Yaw seems to be off or no?
 
Sounds normal to me. You can test each motor individually from the GUI which is a good way to check the motors and ESC's.
The Yaw is the compass heading so it may read anywhere from 0 to 360. All of the values change as you move the Q. Do not do the ESC assignment.

If you have the patch cable that connects from the camera to the Q500, you do not need those wires on the gimbal. Simply tape up the loose wire. After installing the dampers put some dental floss through the holes and tie a loop with some slack so the gimbal can move freely but will prevent the two halves from separating.

 
If you are able to (or know someone who is) it also very simple to just solder them back in place. I once bought a crash damaged CGO3 with steady grip and it was very easy. There are a lot of wiring diagrams on the internet, which will help you to determine were all the wires go. Sometimes the soldering pad on the circuit board is also ripped off. In that case you will have to solder it do the contacts of the connector (the one which is visible from the outside and not in use right now). Again there are a lot of wiring diagrams available.

Just like my previous speakers I believe it is highly unlikely for a Q500 to lose a propeller in flight. Actually it is the very first time I have heard of an incident like this. Usually when this happens the threads have been damaged due to forcefully mounting the wrong propeller on the wrong monter once in the past. In very rare occasions it might also happen that the propeller brakes apart. Usually this is also caused by mishandling.

Losing an entire propeller without any previous events of mishandling whatsoever is basically impossible. Have you found the propeller which got lost? Maybe the thread was damaged?
 
I'm 99.9% sure that a prop can't undo itself in flight due to the opposite rotation of the motor and the prop threads .....
actually I think they can if it gets caught in it's own prop wash. but normally that's done by coming down fast in a straight line. and even that's an iffy...
 
actually I think they can if it gets caught in it's own prop wash. but normally that's done by coming down fast in a straight line. and even that's an iffy...

I do not think, that the propeller can be unsrewed by prop wash. But it might be possible if you manage to decelerate the motor faster than the propeller. Since the motors have active braking it might be possible. But as the propeller are very lightweight, while having a high air resistance, it is not that likely to happen. The only way to achieve it, is by flying upwards and than rapidly pull down the throttle. Due to inertia, the model will keep going upwards for a second, which supports the spinning of the propeller, while the motors are braking. Similar combinations of rotations would also work.
 
So I just got the 4k yesterday and made sure all firmware was up to date and calibrated everything. Took it out for first flight today. Took off and hovered at about 10 feet for a couple minutes and all good. Climbed and started out, it gets to about 40 feet and the thing throws a prop, flips over and crashes upside down! Im 100% sure they were tightened snug. As a rookie I'm at a loss. Looks like a new body, gimbal mount and learning to work on it is in my future.
Yep. The same happened to me. The offending prop wasn't tightened properly.
 
So I just got the 4k yesterday and made sure all firmware was up to date and calibrated everything. Took it out for first flight today. Took off and hovered at about 10 feet for a couple minutes and all good. Climbed and started out, it gets to about 40 feet and the thing throws a prop, flips over and crashes upside down! Im 100% sure they were tightened snug. As a rookie I'm at a loss. Looks like a new body, gimbal mount and learning to work on it is in my future.
I have two to Q500s , I have had three or four motor post and almost all of the propellers stripped out because of the lightning quick changing rotating torque force generated upon the threads ,unfortunately it is a terrible design to use non-forged aluminum . I am very sorry to say it , I have a lot of good experience with YUNEEC products but this design is an absolute crucial flaw ,it can never be trusted to be a true workhorse .
 
Well at least I'm not the only one this has happened to. Still disappointing but it is what it is. After looking around online I think I'm going to get the rakon heli body and landing gear. Expensive but at least if you break something you can change that part and not the entire body. Plus with the aluminum canopy and mounts, since I'm a powder coater, I can change the color scheme whenever I want
 
I think I'm going to get the rakon heli body
I've heard pro's and con's of that body regarding changes in the flight behavior.
Just curious.......it it possible to patch up the Q with tape and test fly it w/o the camera?
 
Right! Please elaborate for the rest of us , how to screw on propellers properly. And I don’t just fly once a month I fly probably five times a week .
Seriously he just joined today and that's his first
I've heard pro's and con's of that body regarding changes in the flight behavior.
Just curious.......it it possible to patch up the Q with tape and test fly it w/o the camera?
I used some Qbond on the cracked pieces and it seems pretty sturdy. Fired it up and just let the motors run for about 5 minutes and there didn't seem to be any vibration. I'll test it out when it's light out tomorrow and report back. And I quadruple checked the props!
 

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