WTH Just Happened? Props just flew off!
- Thread starter jshull0
- Start date
Inspire1 has active braking on the motors, Phantom does not hence the prop locks.
Also the black coating on the motor shafts seems to come off and "jam" the treads so even if the props seems tight they might not be on all the way. It has been advised to clean the treads with alcohol and ensure they are on all the way. Might be something to check?
Strange all 4 props came off.
Also the black coating on the motor shafts seems to come off and "jam" the treads so even if the props seems tight they might not be on all the way. It has been advised to clean the treads with alcohol and ensure they are on all the way. Might be something to check?
Strange all 4 props came off.
Yeah prop locks are an interesting idea, I'm just hoping that the issue wont resurface once all the replacement parts come in (2 motors 2312, 1 ESC v2.1, 5.8 Ghz receiver, Shell, anti static compass landing gear, and gimbal bent). I also broke one of the rf cables from the wifi module to the patch antenna, don't know how I'm going to find that.
jshull0 said:
Both my v3's DID come with the prop wrenches (12/30/14 delivery direct from dji CA).
The wrench APPEARS to not fit well but actually does: the motor frame is a bit triangle shapped, so trying to put wrench straight in from side often does not go on; but place wrench ABOVE the frame and lower it onto it and it fits perfect.
From all the props falling off stories I have made sure I very highly torque my props on, no self tightening for me!
It may be good probability if the battery voltage drops near zero, this 0v dc bus supply to the esc pwm circuits may cause near instantaneous stopping (deceleration) of all the motors at the same time, causing only finger tightened props to spin off. Assuming this was a battery issue as it sounds, then even if these particular props were tightened enough to not unscrew, it still would have crashed the same.
All that would do is save your props. A battery or ESC failure that would cause the props to spin off from a sudden stoppage would not stop the Phantom from an uncontrolled hard landing.jshull0 said:
Just conjecturing here as I have no cold weather flying experience, but seeing as you were flying at 11,600' ASL and you had already flown out almost 2,000' at speed, I wonder if the ambient temp at that altitude combined with the wind chill factor could have caused your battery voltage to drop precipitously low enough to cause some weird things to happen in the central logic circuitry that drives the motors, possibly causing a sudden stop or even motor reversal, if that's even possible.
It would be an interesting experiment for someone to do who lives in a really cold part of the country: tie or weigh down your Phantom so it can't take off and tip it slightly forward in a flight attitude, set up a large box fan in front of it to simulate wind at flying speed and to make sure things get really cold inside and then run the motors at about 1/2 to 3/4 throttle and monitor the battery voltage and motor operation. I do know that really cold temps can shorten the flight time and available voltage really quickly.
What was the ambient air temp where you were flying and what was your forward speed? (for anyone willing to try simulating this for you)
I'd try it for you, but unfortunately I live in sunny SoCal where it's currently 85 degrees outside.
Any takers on the experiment?
Gary
It would be an interesting experiment for someone to do who lives in a really cold part of the country: tie or weigh down your Phantom so it can't take off and tip it slightly forward in a flight attitude, set up a large box fan in front of it to simulate wind at flying speed and to make sure things get really cold inside and then run the motors at about 1/2 to 3/4 throttle and monitor the battery voltage and motor operation. I do know that really cold temps can shorten the flight time and available voltage really quickly.
What was the ambient air temp where you were flying and what was your forward speed? (for anyone willing to try simulating this for you)
I'd try it for you, but unfortunately I live in sunny SoCal where it's currently 85 degrees outside.
Any takers on the experiment?
Gary
I've flown the FC40 at 5 degrees at 6,000 feet for an hour or more without any issues.
Another member flew at 30 or 40 below but that was just for about 10 minutes. Not sure if that was a P1 or P2.
The weather was beautiful yesterday, 70 here, and I'm at least 300 miles north of where he was flying.
I bet it was no where near 0.
Another member flew at 30 or 40 below but that was just for about 10 minutes. Not sure if that was a P1 or P2.
The weather was beautiful yesterday, 70 here, and I'm at least 300 miles north of where he was flying.
I bet it was no where near 0.
If you plan to try for warranty repair, you may not want to answer the temp question publicly. The official spec for your whole phantom (battery included) is 0-40C. Now if you do not plan on asking for possible warranty, then let us know the temp!
suprizingly enough, the ambient temperature was only 38 at 10am according to the jeep and I was only dealing with a north wind of maybe 3 MPH. Honestly it was the nicest weather I have flown in for some time. The tracker shows my max mph reaching 38 at 1200' out, I was pushing full foreward roll for a bit. Problem happened right after hitting reverse roll, been pondering the whole situation all day. I'm just worried that this isn't the last time I'm gonna deal with this.
yorlik said:
I honestly don't think I'll have much of a case for a warranty especially since I have no actual footage of failure. All I hear is how much of a hastle it is to deal with DJI, I do have the form for warranty, but still debating. I have already ordered all the replacement parts and will put my electronic tech skills to use soon. Hoping to not be down and out for too long.
What does everyone think about adding a HD keychain cam to their bird. Honestly I would have loved to have video to the ground with sound, I'm sure that it would have helped with diagnosis.
Sorry about your crash. Glad you had a tracker that worked to help find your bird!
I've found data from my flytrex (core 2) very valuable in diagnosing what went wrong. http://www.flytrex.com
Out of curiosity, what does that battery life say? I've had problems (auto land) with them below 90%.
MHL
Fplvert said:
Sorry about your crash. Glad you had a tracker that worked to help find your bird!
I've found data from my flytrex (core 2) very valuable in diagnosing what went wrong. http://www.flytrex.com
Out of curiosity, what does that battery life say? I've had problems (auto land) with them below 90%.
MHL
Oh those flytrex live loggers have some sweet features, the only thing that sucks is I'm flying in a lot of no cell service areas which take away functionality of the flytrex especially for recovery. The only reason I went with a rf tracker is because of the lack of cell service. I can see having it along side of the rf tracker, and not have to use vision+ utility every time I fly.
Oh, and the battery was showing 50% after the crash. Once I got everything home a few hours later it said 75%. I've never seen a DJI battery show a different value after sitting idle unless it's auto discharging. I've also never seen a battery discharge so quickly after a 3 min flight.
Sorry misunderstood, and It shows 90 - 100% which I guess makes sense seeing as how I only have a max of 30 cycles on it.
So, we're still wondering WTH really happened, aren't we?
I would like to know more about your battery.
What is the discharge rate?
What does DJI say about battery performance at high altitudes? :lol: Yea, I know that was funny.
If I read your posts correctly, you took off from 11,000 feet above sea level, with the ambient air temp between 30 and 40 degrees Fahrenheit, & went straight up quite a ways, then went hauling butt for a quarter mile with a top speed of 38 mph and hit reverse,
so to speak.
I don't think this really is a factor, but it may be.
Can you guess what the temperature of the battery was when you started the motors?
Did it spend the night in the trunk of the car?
I'm leaning more and more towards "sucking the power faster than the battery can supply".
When I do that to my dumb batteries, they just make the bird want to land.
I wonder what happens to those smart batteries when they drain too fast.
I think we may have just found out.
I would like to know more about your battery.
What is the discharge rate?
What does DJI say about battery performance at high altitudes? :lol: Yea, I know that was funny.
If I read your posts correctly, you took off from 11,000 feet above sea level, with the ambient air temp between 30 and 40 degrees Fahrenheit, & went straight up quite a ways, then went hauling butt for a quarter mile with a top speed of 38 mph and hit reverse,
so to speak.
I don't think this really is a factor, but it may be.
Can you guess what the temperature of the battery was when you started the motors?
Did it spend the night in the trunk of the car?
I'm leaning more and more towards "sucking the power faster than the battery can supply".
When I do that to my dumb batteries, they just make the bird want to land.
I wonder what happens to those smart batteries when they drain too fast.
I think we may have just found out.
jshull0 said:
Probably dumb question, but if you are using the vision + utility, doesn't it log all the variables for you on a csv file on your phone while flying? I know the standard dji phone app that came with it does not, but I thought I read the apple v+ utility thing did?
This is a main reason I switched to KenArgos 'dji ultimate flight' program: I get cvs every second of ALL dji variables sent - that includes current draw and voltage level. THAT log could take the mystery out of the battery performance in those last few seconds.
It would be SWEET if you have this log and just did not remember....
- Joined
- Oct 6, 2014
- Messages
- 502
- Reaction score
- 21
I just had a customer contact me from Florida. Same exact thing just happened to him with his 5 week old Version 3. Was flying at 60ft elevation and all 4 motors shut down while he was flying forward. It came crashing to the ground totaling it. I have referred him to DJI, if they dont know whats going on they wont fix it. It has to hit them in the pocket book for them to change it.
Jeremy
Jeremy
burlbark said:
EXACTLY same scenario for our #2 unit, 4 wk old. sent back to ca dji with paperework filled out requesting warranty rpr due to bad battery. time will tell...
