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I Can't Believe it! MY "New & Improved" shell has a crack after 7 flights!
- Thread starter CONTROL FREQ
- Start date
There are no extreme temperatures involved. There was a thread a few months ago where a guy tracked the temps at the motor mounts and found nothing beyond slightly warm
When you think about it, there's really very little besides the vibration from the propellers that could be causing these cracks. There's not likely much torsional stress on the airframe during flight, but the jackhammer effect over time of four high rpm props would definitely lead to cracks eventually if 1 or more of them are out of balance. It could even cause electronics failure after a while and possibly lead to the battery vibrating and disconnecting if it's bad enough. This is a plausible explanation for the folks here reporting cracks or other random failures even though they "baby" their Phantom. It's no big deal to balance, and removes one variable.
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my quad hovers perfectly and the video is flawless with no vibration with the new props, but I ordered the Du-Bro 499 Tru-Spin Prop Balancer anyway because I want everything to be right.
thanks guys.
thanks guys.
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I was thinking that maybe it was the way I was flying my unit.
When I got my first unit in June, I would do things like fly 30 mph going forward and in all in one motion, do a 180 degree about-face and then fly backwards without losing speed.
I thought that maybe maneuvers like that was what was putting all of the stress on the motor mounts and causing the cracks. So I stopped doing maneuvers like that and I'm still getting cracks!
But by doing moves like the one above, I'm sure that would put some pretty good stress on parts of the quad, right?
I'm having my doubts about unbalanced props being the culprit in my case.
I have ordered a set of Dji 9450 CF props for comparison with the OE props. I know they are a bit stiffer, but they may be lighter (unconfirmed). I will definitely balance them on a Du-Bro 499 before I fly (you must get the P3 balance rod to work with the Du-Bro)
This is what Dji says on their website:
"Another masterpiece by DJI Propulsion Laboratory. Aerodynamically optimized and precisely manufactured, the Z-Blade 9450 propellers produce powerful thrust with excellent dynamic balance.
These reliable blades easily handle your FPV and other payloads while keeping your platform stable and virtually vibration-free, helping reduce the chance of jello or other unwanted effects."
FYI: no cracks yet in mine and I've had it for 6 months with one crash the first week where I actually had to straighten the shell near one of the motors.
This is what Dji says on their website:
"Another masterpiece by DJI Propulsion Laboratory. Aerodynamically optimized and precisely manufactured, the Z-Blade 9450 propellers produce powerful thrust with excellent dynamic balance.
These reliable blades easily handle your FPV and other payloads while keeping your platform stable and virtually vibration-free, helping reduce the chance of jello or other unwanted effects."
FYI: no cracks yet in mine and I've had it for 6 months with one crash the first week where I actually had to straighten the shell near one of the motors.
Sure, there are all kinds of stresses involved in flight, vibration doesnt show up in video unless the settings are totally wrong. And a good hover has nothing to do with the lack of vibrations. Its not even so much the vibration of one prop. Its the overall harmonics produced by all 4 props, and how they interact with each other. At different motor speeds, and different stress level the vibrations can do some CRAZY things!! Even variation in pitch across all 8 blades at varying RPM has potential to cause incredible amounts of vibration.
In the above video this guy is trying to find whats causing his vibration problem. He SEEMS to have balanced everything very well. But you can see vibration in the tail when its spinning up at about the 1:24 mark. Its pretty clean most of the time, but thats pretty significant if the the main rotor had a similar unseen issue and they two just happen to his the right RPM at the same time. The P3 has potentially more of a potential issue because of 4 blades, tied to 4 motors hanging on 4 arms.
In the above video this guy is trying to find whats causing his vibration problem. He SEEMS to have balanced everything very well. But you can see vibration in the tail when its spinning up at about the 1:24 mark. Its pretty clean most of the time, but thats pretty significant if the the main rotor had a similar unseen issue and they two just happen to his the right RPM at the same time. The P3 has potentially more of a potential issue because of 4 blades, tied to 4 motors hanging on 4 arms.
I have a set and they needed similar balancing to the standard props.
Not much obvious difference in use, they look nicer and don't show gruesome bug guts so much.
Oso
Premium Pilot
@CONTROL FREQ - To balance my props, I simply use the handle of a common x-acto knife. It fits perfectly in the hub, and then I set it on top if a thin lipped glass on a level surface. I have found the P3 props to be very balanced and have only had to use a small piece of tape on 3 of the 8 props that came with my P3. I suppose I could get the Du-Bro for ~$25 US and then more for the P3 rod. Lord (and my wife) knows I love to buy things, but sometimes I also go with something free and simple that works well enough. FWIW, 178 flights since May 15 and no cracks. As always, your mileage may vary.
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I have flown over 100 flights and most of them with the carbon fiber props. No cracks on mine.
I disagree yes you can change braking settings in the DJI GO App.
If braking is set to say 120% and the phantom is flying in Atti mode and being flown along in the wind at a rate of knots and you flip the switch to P-GPS mode. You think the sudden stopping of the craft doesn't cause immense strain on the body. I try to ease any changes of direction or speed.
If as I did in a recent flight. Whilst still in Atti mode pointed into the wind increasing the speed gently bringing the phantom to a near standstill. Before changing to GPS mode. I think we should all think of the stresses we put on the craft and the side effects.
People keep coming up with all sorts of weird and wonderful theories. Bad moulding or too tight a screw caused that!!!
Want to feel some bad vibrations? Try a chainsaw - plenty of them have plastic casings these days!!!
Seriously though it comes down to quality control.
Want to feel some bad vibrations? Try a chainsaw - plenty of them have plastic casings these days!!!
Seriously though it comes down to quality control.
My chainsaw doesn't vibrate, I balanced the, um, chain.
I'd like to have a Phantom made of carbon fiber.
I fly the living hell out of my P3P daily! Never a crack. And shes 9 months old now.
Chainsaw vibrations?? Really? Are you REALLY that far out of touch with everything involved here? a FART vibrates too! So why are chairs not cracking? I needed a good laugh! But thats about the worst drunken post Ive ever seen on the internet! At least I hope thats what it was.
Oso
Premium Pilot
I was secretly hoping that you would see his post and reply. ;-)
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Sand the bottom of the blade. Aerodynamics are the same. Sanding the side of the prop won't change the aerodynamics significantly either.
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About 1 out of 4 DJI props are extremely close or exactly balanced according to my Dubro. 1 out of 4 DJI props take almost an act of God to get balanced (sand, sand, sand and sand some more), some suck!
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