Drone not able to take off/Propeller trouble

Hello all, we just got our drone’s software up and running and did our first test flight in stabilized flight mode today. The only issue was that we weren’t able to get the drone off the ground, and the props had some…issues. I’ve pinned the inability to lift off the ground to the fact our battery was drained down to 15.6-7 volts which (according to some research) might affect the power given to the motors. However, the issue with the props is what evades me. We ensured that our motors were on in the correct orientation and that our props were secured properly, but no matter how many times we tried, the propellers just shoot off the top of the drone. If it will help, I can record a video tomorrow of another test flight and append it to this topic. Please help! My team and I are quite concerned with this development!
-Ryan Mathews, team 1000A

1 Like

The drone should be able to take off with a low battery like that. It won’t be as happy about it as it would be on a full battery, but I am confident that is not your issue.

If I had to guess, I don’t think they were secured properly. A properly secured prop would not fly off the motor. This leads me to believe that something in the way you are attaching the props is the issue.

Yes please! Pictures and videos will always provide more context than text ever will. Posting pictures and linking to videos will only help in your trouble shooting process.

If a picture is worth 1000 words… then a video must be = 1000*(frame_rate)*(length_of_video_in_seconds). Huh. I’ve never thought about it like this before.

Oh, and also, you don’t need to sign your posts. Every post has your profile information attached to it. Check out the last bullet of the Keep it Tidy section of our Community Guidelines.

3 Likes

The first time we ran ours, the drone went into the air, and when it landed, two of the props flew off the top. Not sure if the kids tightened them down enough, but I tightened the props down and they didn’t come off during the 2nd flight.

Not really sure why it happened the first time.

2 Likes

It’s not uncommon on drones for the props to come off during certain conditions. The conditions that are most likely to see this phenomenon are when the motor (and by extension prop) experience high torque situations.

For the landing example, when the drone is coming down to land the motor is providing enough lift to keep the drone at a slow descent rate, and when you disarm the motor stops producing torque, and in some cases ESCs can induce a braking function. This sudden deceleration coupled with the props momentum can cause the prop to want to keep spinning and thus fly off.

Long winded response, but in my experience superglue has been a good solution to this. Just understand that it will require more effort to remove the prop.

Back to your original issue: have you by chance calibrated your ESCs? Perhaps the throttle range isn’t mapped correctly.

1 Like

Here’s the link to our test flight video, we did everything the documentation said to do, including the motor calibration. Please let me know anything else that I can submit to help document this issue.

Is it possible that the speed the drone ascended played a role?

We’ll try recalibrating the motors tomorrow when we meet, I’m quite confident that isn’t the issue, however. In the end we most likely will end up supergluing the props on, hopefully that fixes our issues :slight_smile:

I would also double check that your flight controller has been properly calibrated (all sensors: accel, gyro, and magnetometer).

@Ryan_Mathews_1000A could you also perform a motor test in QGC (with props off) and confirm that the correct motor spins when you activate each of the individual channels?

Our drone takes off and flies just fine, we have done a few throttle test quick assentation and hover, yaw test, left and right direction test and things are working great, but when we go to land, and go back to idle our rear propellers fly off just as we set down. I have personally have made sure they are on tightly and in the correct direction. Is there a solution or reason as to why this happening.
If you need a video we can get you one.

We’re yet to solve the issue, our mentor is coming in tomorrow, so I’ll be discussing the issue with him at that time. If there is another solution besides supergluing the props to the motors, I’ll let you know!

@bhanner-bell We ran the test, and everything appears to be perfect, we attached a piece of tape, spun them slowly, and visibly observed the motors spinning in the correct direction. We can re-calibrate the fc tomorrow with our mentor there to ensure we do everything correctly.

An update: we solved the issue. We noticed that two of our motors weren’t spinning in the correct direction and remembered that we were instructed to switch two of the motor leads to reverse the polarity last year. After taking this advice again, the propellers stayed attached the whole flight, and we were finally able to get the drone off the ground and into the air!

1 Like