alokbhargava
Premium Pilot
This is your forum. Keep on expressing your views to help other members. Ignore what you don't like.
Bummed. New P3A Crashed. Pls Advise
- Thread starter McVenturesRC
- Start date
This is your forum. Keep on expressing your views to help other members. Ignore what you don't like.
What does it matter who is right? The idea is to discuss the hobby and help one another and ourselves by exploring possibilities. I said a prop could come off in flight. You said I was "seriously confused". Are you going to explain that?
I have no idea what you're implying. Who said there was a master plan to sabotage anything?
The implication was that under the right conditions, a prop could come off.
He crashed into grass. Chances are if a motor bearing failed that will be apparent.
Noone ever questioned the OP's honesty or integrity. His crash has absolutely nothing to do with honesty and integrity. Nor do I see where he ever offered up anything questionable.
Again, not sure why you're coming up with this stuff. We were discussing the reason for his crash and the "possibility" that a prop spontaneously unscrewed itself....along with the 100 other potential reasons for his crash.
Hopefully we'll all learn from the findings and avoid crashing for the same reason(s).
Peas.
alokbhargava
Premium Pilot
Active braking will never unscrew any prop cause the direction of rotation of motors still remain the same.
True, but not relevant
100% false. that is specifically why the nylon hub props were created and DJI specifically warned against using the old P2 props to prevent Active Breaking from dislodging a prop
alokbhargava
Premium Pilot
My understanding is that log data will show if the motors were spinning. Log can't differentiate if all motors had props.
No, it cant fly because the one wrong blade would have the opposite force needed. It would likely NOT fly off or unscrew because the cross threading would be too tight.
Anyone who gets upset or personal over a discussion of toys needs therapy. lol.
Tighten those props and go enjoy the beautiful weather and log some flight time
McVenturesRC, you've got some packaging to do.
Tighten those props and go enjoy the beautiful weather and log some flight time
McVenturesRC, you've got some packaging to do.
The spinning shown in the log, at the rate it is indicated, can only be created with one prop/motor jeopardized
Yep. Just waiting for the RMA. Thanks for your help everyone! Lesson learned. Still can't picture the mistake in my head but it doesn't matter. Birds not gonna fly with 3 props. Live and learn to be more cautious.
alokbhargava
Premium Pilot
I would like to see the statement of DJI. Can you point me to the link? Thanks.
Active braking puts extra stress on hubs and we need stronger hubs to take care of these stresses.
Finding the RIGHT cause is the only thing that solves the problem, and the only thing that everyone can learn from. All the speculation and superstition in the world will never HELP anyone. Only further confuse them!
If you actually READ what this was replying to you might understand.
I didn't say there was a question of integrity or implication of anything questionable. Many of the fools that post up crash info simply vanish, never to admit that THEY were the cause of their crash. Are you seriously trying to attack me for commending a guy and his honesty? Get over yourself!
There was never a possibility of the prop coming off. It was always a known, just not understood by many. There was ALWAYS only two possible failures, both pertaining to a prop coming off. All the other speculation was nothing but that. EVERYONE needs to get off their soapbox, calling out random insanity as causes simply because they read it somewhere. This is a place to learn.. for everyone. For me, I learned that it can even be wrong to commend someone! Thank God there is an ignore button!
alokbhargava
Premium Pilot
All intra-personnel problems will be resolved if we stick to technical explanations or our practical experience and avoid using I or You in conversation. All do not have same nerves, some get pissed off easily. Let's stick to the topic only and avoid personal criticism.
I poked around a bit, but couldn't find anything from DJI. Only a ton of talk here and on RCForums and DJI forums about it. The descriptions of the P2 prop states its compatible with the P2 line, and the P3 prop states its compatible with the P3 line. That all I found definitive.
alokbhargava
Premium Pilot
You are right, we should always use the recommended props.
Slightly off topic : Are the props same for the new motors too, they are rated lower? Hope current limits on new ESCs and better motor efficiencies is taking care of the deviations.
There has been no change in the P3 prop since introduction. And no mention of expected changes.
There has been a lot of confusion, speculation and misinformation about props coming off in flight. I decided to do some actual testing to demonstrate this failure. I used my F550 hex with only one prop attached. It has the same motors, props and flight controller as the earlier Phantoms but not the same as the P3.
In my first test, I installed the prop as loosely as possible and tried to make it fly off at idle speed by grabbing the motor bell. This was not successful. Just starting up the motor tightened the prop enough to keep it on. I also tried at higher speeds up to the point that the arm was bending as the bird tried to lift off. After multiple tries, I was able to make it fly off.
Note: in these videos, the props appear to be stopped or spinning slow when at idle speed. They are in fact spinning very rapidly but at a speed that is nearly in sync with the frame rate of the camera. Anyone who has shot video of props in flight will recognize this.
I tried holding the motor bell with one hand while spinning the prop on quickly so that it seated with a “thunk” against the shoulder. I also tried placing the prop on the very top of the shaft without spinning it at all and letting the motor wind up and seat it with an audible “thunk.” In these cases, it took considerable effort to remove the prop by hand, but a wrench was not necessary. Again, it took many tries even at high speed, to make a prop fly off.
This prop was a 9443 P2 prop without the composite hub so it would not have as much friction as the P3 props. The ESC does not have active braking, but I was grabbing it and bring the motor to a complete stop as quickly as I could by hand.
Next, I disconnected one of the 3 wires from the motor to the ESC and replaced it with a jumper wire that I could disconnect while the motor was running. This would simulate an ESC failure, power loss or bad solder joint failure in flight. I started up the motor as usual and ran it up to speed, then disconnected the motor wire. The motor stopped instantly. The prop flew way up in the air and trimmed my wife’s ferns hanging above. This was absolute, consistent and repeatable at different speeds.
For me, this issue is very clear. I believe if your prop comes off in flight, it was likely caused by an electrical failure. If you still believe otherwise after watching this, please do your own test and convince yourself or post the video if you can demonstrate a different result.
I would love to see a real test with the P3.
In my first test, I installed the prop as loosely as possible and tried to make it fly off at idle speed by grabbing the motor bell. This was not successful. Just starting up the motor tightened the prop enough to keep it on. I also tried at higher speeds up to the point that the arm was bending as the bird tried to lift off. After multiple tries, I was able to make it fly off.
Note: in these videos, the props appear to be stopped or spinning slow when at idle speed. They are in fact spinning very rapidly but at a speed that is nearly in sync with the frame rate of the camera. Anyone who has shot video of props in flight will recognize this.
I tried holding the motor bell with one hand while spinning the prop on quickly so that it seated with a “thunk” against the shoulder. I also tried placing the prop on the very top of the shaft without spinning it at all and letting the motor wind up and seat it with an audible “thunk.” In these cases, it took considerable effort to remove the prop by hand, but a wrench was not necessary. Again, it took many tries even at high speed, to make a prop fly off.
This prop was a 9443 P2 prop without the composite hub so it would not have as much friction as the P3 props. The ESC does not have active braking, but I was grabbing it and bring the motor to a complete stop as quickly as I could by hand.
Next, I disconnected one of the 3 wires from the motor to the ESC and replaced it with a jumper wire that I could disconnect while the motor was running. This would simulate an ESC failure, power loss or bad solder joint failure in flight. I started up the motor as usual and ran it up to speed, then disconnected the motor wire. The motor stopped instantly. The prop flew way up in the air and trimmed my wife’s ferns hanging above. This was absolute, consistent and repeatable at different speeds.
For me, this issue is very clear. I believe if your prop comes off in flight, it was likely caused by an electrical failure. If you still believe otherwise after watching this, please do your own test and convince yourself or post the video if you can demonstrate a different result.
I would love to see a real test with the P3.
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