Inspire 2 Falls fromd the Sky, arm problem?

[Lesmess]

I have now added additional checks to my normal inspection routines, I now check motor arm tightness on a weekly basis. I upgraded to T-Motor CF props not long after purchasing my inspire as I was not happy with the rattling prop issue. I then bought a set of folding props, I took them off after several flights, continual overspeed warnings and severe shake on start-up was annoying. The whole frames shakes on start up even if you straighten the props, this can't be good for motor to frame integrity over a period of time if there is a issue with the motor to frame bonding. The t-motor props are in my opinion far superior to the stock DJI props and the folding props I installed. She is much more stable with better response to control inputs, no issues with warnings apart from the usual high wind warnings. I will not be purchasing a set of motor braces unless the issues with motor to frame failures are increasing to a point where it can no longer be considered
as isolated incidents.

 

[Phil DeVore]

This kind of issue is very hard to detect. It is not something gradually worsening which would be possible to feel by trying to twist or pull. It is a type of sudden failure without any upfront warning and hence totally undetectable by any tugging or twisting. I personally agree that all these preflight forces applied frequently can only make the matter worse. The only safe remedy IMHO is some kind of external brace which would hard connect the motor mount to the CF tube or a jesus bolt through the mount and the CF tube with a locknut on another side. I was told however that drilling through CF can impact on integrity a of the CF as it cuts through the fiber strands. I have come across a NZ company Drone Depot which makes a brace and it looks like a solid design to me. I have no association with that company whatsoever but I am buying a set for my I2. It will give me peace of mind and provide extra safety which is crucial for my line of work.

Do you have a link for that Drone Depot so I can look into purchasing the motor clamps you spoke about

 

[Phil DeVore]

Sorry I found this company concerning the braces you spoke about and I went ahead and ordered a set from them as I want to be sure that this problem does not happen with my Inspire 2. Yes the price is a little bit expensive (not even close to the price of the Inspire) but I will have some peace of mind when I am up in the air so that makes the price a little easier to swallow.
Phil DeVore

 

[Phil DeVore]

Do you have a link for that Drone Depot so I can look into purchasing the motor clamps you spoke about

Thanks for the link to Drone Depot NZ!

 

[Phil DeVore]

View attachment 18007

I have now added additional checks to my normal inspection routines, I now check motor arm tightness on a weekly basis. I upgraded to T-Motor CF props not long after purchasing my inspire as I was not happy with the rattling prop issue. I then bought a set of folding props, I took them off after several flights, continual overspeed warnings and severe shake on start-up was annoying. The whole frames shakes on start up even if you straighten the props, this can't be good for motor to frame integrity over a period of time if there is a issue with the motor to frame bonding. The t-motor props are in my opinion far superior to the stock DJI props and the folding props I installed. She is much more stable with better response to control inputs, no issues with warnings apart from the usual high wind warnings. I will not be purchasing a set of motor braces unless the issues with motor to frame failures are increasing to a point where it can no longer be considered
as isolated incidents.

Where did you get the tmotor propellers from please.

 

[STKNRUD]

View attachment 18007

The t-motor props are in my opinion far superior to the stock DJI props and the folding props I installed. .

. I’ve been told not to use CF props. The lack of flexibility transfers more stress to mounts. It sounds intuitively correct.

 

[CSpenceFLY]

After seeing the video above that shows the Inspire with the motor assembly off, it's pretty obvious what the problem is. With the end of the tube cut in half there is not proper pressure on the adhesive while it's setting. There should be a collar or grommet installed at the time of assembly inside the tube to fill in what has been removed and create pressure against the two surfaces while the adhesive sets.

 

[samtheparrot]

View attachment 18007

I have now added additional checks to my normal inspection routines, I now check motor arm tightness on a weekly basis. I upgraded to T-Motor CF props not long after purchasing my inspire as I was not happy with the rattling prop issue. I then bought a set of folding props, I took them off after several flights, continual overspeed warnings and severe shake on start-up was annoying. The whole frames shakes on start up even if you straighten the props, this can't be good for motor to frame integrity over a period of time if there is a issue with the motor to frame bonding. The t-motor props are in my opinion far superior to the stock DJI props and the folding props I installed. She is much more stable with better response to control inputs, no issues with warnings apart from the usual high wind warnings. I will not be purchasing a set of motor braces unless the issues with motor to frame failures are increasing to a point where it can no longer be considered
as isolated incidents.

I did the same and couldn’t agree with you more...the T-Motor props are superior and perform very well. I changed mine over right after I got my I2...to this day at least to my knowledge, DJI hasn’t acknowledged the prop issue, and still maintains its safe to operate...still seems crazy to me a year later.

 

[samtheparrot]

. I’ve been told not to use CF props. The lack of flexibility transfers more stress to mounts. It sounds intuitively correct.

I’ve not heard that one..they are obviously very rigid, but seems hard for me to comprehend DJI calculates prop flex as part of their vibration management, and DJI has no concern with the stock props vibrating away, just one mans option, and I’m not as sharp as Frank Wang.

 

[Phil DeVore]

. I’ve been told not to use CF props. The lack of flexibility transfers more stress to mounts. It sounds intuitively correct.

I have been using CF propellers for 6 months and haven’t had any problems so far. Mine are the T-motor winglet style propellers from Florida Drone Supply that I just purchased. I was using the Coptermax folding CF props before I switched recently and they did have some vibration issues unless I unfolded them prior to startup but if I unfolded them they didn’t have the same issues.

 

[STKNRUD]

I’ve not heard that one..they are obviously very rigid, but seems hard for me to comprehend DJI calculates prop flex as part of their vibration management, and DJI has no concern with the stock props vibrating away, just one mans option, and I’m

I’ve not heard that one..they are obviously very rigid, but seems hard for me to comprehend DJI calculates prop flex as part of their vibration management, and DJI has no concern with the stock props vibrating away, just one mans option, and I’m not as sharp as Frank Wang.

I may be wrong but I don’t think DJI offers a CF prop. Why not? That makes the addition of one a “modification” which could influence warranty. Wang is definitely a smart businessman but this and other forum posts suggest the products are not without design flaws. I doubt Wang oversees every aspect of even the engendering of each product any more than Tim Cook does.

 

[STKNRUD]

These kind of airframe issues concern me and not because of the personal cost. I know that this is a 1 in a million type of event, but an airframe failure that causes a major injury/death of a heavy, large professional drone is different than someone being hurt from a stupid pilot error. As many recall when the FAA first got involved in model aircraft/drone regulations, they wanted everyone to have a pilot’s license (still do) and wanted certification of airframes and regular inspections. I know a lot are thinking...”ain’t going to happen”...”impossible to do”...and you might be right. But it is not beyond the realm of possibility that such things could be required in the future for larger professional drones. In addition, anything will be used as primfacie evidence more regulations of all types are required. I hope DJI is considering this as much as they are other safety designs like NFZ restrictions, etc. Maybe they aren’t doing enough in terms of fatigue failure tests, etc. of these larger drones. They have come a long way since the first Phantom with the Inspire and Matrice series. If they rely on us to do the beta testing of OS, maybe they need to look at what impact airframe issues have on more than warranty costs. I am concerned because they don’t show much interest in being transparent about many issues.

 

[FlyaDrone]

If a licensed part 107 pilot becomes involved with creating an "incident" which rises to the level of legally requirng the pilot in charge to formally submit a report to the FAA, it will become much more serious than the current level of speculation which all of us are currently engaged in. Airframe fatigue in pepole transporting aircraft is consistantly inspected for, tested for and monitored with all results being documented.

 

[samtheparrot]

I am curious the more I think about this...how many of the “isolated” incidents of this problem were using the stock “rattling” props?

 

[Phil DeVore]

I am so concerned about the problem that I purchased the motor support mounts from Drone Depot NZ. They were mentioned in a previous thread and just for peace of mind I bought a set for $175 because that’s a small price that I am willing to pay so it helps me to feel safer when I am flying where there’s people around. I was told that there’s very few of these incidents but I want to limit my liabilities to innocent bystanders. I definitely don’t want to harm anyone by my not trying to be as safe as possible. Phil DeVore

 

[mmarian]

I am so concerned about the problem that I purchased the motor support mounts from Drone Depot NZ. They were mentioned in a previous thread and just for peace of mind I bought a set for $175 because that’s a small price that I am willing to pay so it helps me to feel safer when I am flying where there’s people around. I was told that there’s very few of these incidents but I want to limit my liabilities to innocent bystanders. I definitely don’t want to harm anyone by my not trying to be as safe as possible. Phil DeVore

Just do not forget to wrap an electrical insulation tape arount the arms before fitting them on. There is a "how to" video, link attached bellow. This is a critical step not to be missed!! I have personally cut eight 33x11mm strips from Gaffer tape and attached them inside of the brackets where they hug the CF tube. The fit becomes nice and snug, the top screws treated with Locktite 243 and tightened just enough to provide enough grip. Otherwise the brackets won't do anything and will become only an expensive decoration on your I2.
Link to video

 

[Phil DeVore]

Just do not forget to wrap an electrical insulation tape arount the arms before fitting them on. There is a "how to" video, link attached bellow. This is a critical step not to be missed!! Otherwise the brackets won't do anything and will become only an expensive decoration on your I2.
Link to video
https://www.facebook.com/dronedepot/...7590342084492/

Do you have the link for that video? Supposedly the company I bought them from is giving me a tutorial on that but I am not counting on it so if you know the link I’ll appreciate it.

 

[Phil DeVore]

Just do not forget to wrap an electrical insulation tape arount the arms before fitting them on. There is a "how to" video, link attached bellow. This is a critical step not to be missed!! Otherwise the brackets won't do anything and will become only an expensive decoration on your I2.
Link to video
https://www.facebook.com/dronedepot/...7590342084492/

Oops I didn’t see the link! Much appreciated.

 

[mmarian]

Oops I didn’t see the link! Much appreciated.

I edited my post and added link..

 

[SteveFPV]

With the incidence of this motor mount to CF tube failure on the rise, and the subject post flight and even in-flight videos, the proof of what is happening is irrefutable IMHO. The integrity of the motor mount to the cf tube arm is not sufficient. A very dangerous flaw which DJI knows about, and in their best interest, should address quickly.