Bummed. New P3A Crashed. Pls Advise
- Thread starter McVenturesRC
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Watch this DJI vid,
This is exactly how I install my props.
Pretty simple, sounds like the OP did it correctly.
This is exactly how I install my props.
Pretty simple, sounds like the OP did it correctly.
in this case it works-- the "self tightening props work well" -- they just don't want folks stripping the threads in that composite hub which is easy to do. If they were metal hubs, you would have to be concerned with enough "torque" to prevent them from back off.
My "finger tight" is potentially double what some people would consider as snug. I have a far great grip than than any normal person. Talk about subjective!! You cant even use the video as a guage for how FAR to rotate after spinning the prop on. he got maybe 3/16 of a turn. I have props that will easily turn 2 rotation after spinning stops. Its all about getting just tight enough to not come off. And thats all.
The props only need to be finger firm. They'll self tighten as the motors spin, so still possibly not your fault.
2 rotations after spinning stops ??
No way, something does not sound right,
Is it possible you overtightened and stripped
out a prop hub ??
No.. its not. Its because the threads arent as clean as they are on other props. So they drag more.There is a proper torque that should be applied. But there is almost no way for the average P3 owners to all have the tools needed. The range is pretty broad, so finger tight, with moderation and little common sense works fine.
Yes they do work well. However, do this....loosen a prop to the point it can spin freely....then spin the prop in it's normal direction of rotation....what happens?
If screws off in a hurry. Surprised?
My point is that if your props somehow work themselves too loose and the motor drops speed suddenly and the prop is free to turn, it can come right off in a hurry. Only air resistance (or the fact that you sufficiently tightened the prop) prevents it from coming off.
This is why DJI says to tighten them with both hands. I do not believe they mean for this to be taken lightly. They mean get them on good and snug.
They are self tightening, as long as there is sufficient air resistance against the prop which is normally. It is that resistance that provides the "self tightening".
I suspect this may happen more often that people think. At high speed, the props have inertia, maybe not a great deal, but they do have some. This is magnified if you were in a rapid ascent because the air flow will tend to push the props in the direction that would also unscrew them.
So rapid ascent (wind descending across the prop) combined with loose prop and at the same time a sudden drop in motor speed occurs would be the perfect storm to lose a loose prop.
Better safe than sorry. Tighten the props enough so that they cannot become loose.
If screws off in a hurry. Surprised?
My point is that if your props somehow work themselves too loose and the motor drops speed suddenly and the prop is free to turn, it can come right off in a hurry. Only air resistance (or the fact that you sufficiently tightened the prop) prevents it from coming off.
This is why DJI says to tighten them with both hands. I do not believe they mean for this to be taken lightly. They mean get them on good and snug.
They are self tightening, as long as there is sufficient air resistance against the prop which is normally. It is that resistance that provides the "self tightening".
I suspect this may happen more often that people think. At high speed, the props have inertia, maybe not a great deal, but they do have some. This is magnified if you were in a rapid ascent because the air flow will tend to push the props in the direction that would also unscrew them.
So rapid ascent (wind descending across the prop) combined with loose prop and at the same time a sudden drop in motor speed occurs would be the perfect storm to lose a loose prop.
Better safe than sorry. Tighten the props enough so that they cannot become loose.
Ever notice that little double acceleration of the props when you start up the motors?? This was describe by a dealer to be for tightening the props at start up-- now I don't know whether that is true or not-- but it makes sense.
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Over-tightening is more of a worry than under-tightening.
Finger firm is just fine.
You run the risk of stripping the threads or weakening them by over-tightening.
When your Phantom powers up and goes vroom-vroom, it's checking that the props are sufficiently tight.
The "sticky" threads in the composite hub have plenty of grip to deal with active braking.
That's exactly why DJI propulsion came up with them.
Finger firm is just fine.
You run the risk of stripping the threads or weakening them by over-tightening.
When your Phantom powers up and goes vroom-vroom, it's checking that the props are sufficiently tight.
The "sticky" threads in the composite hub have plenty of grip to deal with active braking.
That's exactly why DJI propulsion came up with them.
Well, I know this conversation has evolved, but to get back on point, the crash, I don't see what else could have caused it except loosing a prop. Lesson on double checking props! Should have done the Discount Double Check, would have saved me time and money, I presume! Thanks everyone. I appreciate all your comments. I'll let you know when I'm flying again! Maybe before Christmas?
How tight enough is perfect??
I use 1 hand to hold motor and the other to tighten the prop. I think tighter than I could do with just hand
Holding the motor and tightening the prop with just the one hand.
Here's a Question. Why does DJI include a prop tightening wrench? That would be more than just snug I would think.
Dale
I use 1 hand to hold motor and the other to tighten the prop. I think tighter than I could do with just hand
Holding the motor and tightening the prop with just the one hand.
Here's a Question. Why does DJI include a prop tightening wrench? That would be more than just snug I would think.
Dale
that is good enough-- don't even worry about the prop tightening wrench -- you wont need it unless one is too tight and you cant get it off with our fingers.
There is no prop tightening wrench. I bet you dont find that term anywhere on DJIs website, or any of the resources associated with it!
Yeah, I added that in second post.Well Snerd, you know that is a prop loosening wrench
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