Critical Failure of T*Motor Props during shoot

[r62ewa]

Well I do have a set and they are fine.
The props actually comes pre-tourqued to 50 cN.m from the factory. (checked mine and they all where identical).
So here is what I did: backed out the screws 1/2 a turn and retightened to 25 cN.m and they are now fine without any vibrations and still stays fully extended when motors are stopped.

AND there is a locking nut.

Great to know, I could not see one from inspecting it from the bottom.

 

[cougar]

Great to know, I could not see one from inspecting it from the bottom.

Yes I agree, it is quite hard to see the embedded locking ring in the nut, but it is there, made sure before doing any testing on these props. Sorry about your mishap.

 

[r62ewa]

Yes I agree, it is quite hard to see the embedded locking ring in the nut, but it is there, made sure before doing any testing on these props. Sorry about your mishap.

Thanks. Still find it curious how it disengaged the nut even after backing the screw out so little if the locking ring is there.

 

[cougar]

Thanks. Still find it curious how it disengaged the nut even after backing the screw out so little if the locking ring is there.

That I can't say, maybe you backed it out a bit to much or maybe you had a defect nut??
You could also apply a bit of loc-tite as extra security.

 

[r62ewa]

Thanks for the thoughts and comments @cougar. Even though I have an extra set of T-motors I'll now be sticking with the stock set up on my replacement. Let me know if you are in need of another set, I have a pair I'm likely going to sell.

 

[mmarian]

That I can't say, maybe you backed it out a bit to much or maybe you had a defect nut??
You could also apply a bit of loc-tite as extra security.

That I would not recommend. Loctite should not come anywhere near to plastic. It is either one or another. For props the locknuts are always safer option. All RC helicopters have locknuts on propeller pivot screws. Main blades as well as tail. Always had. It is a common practice proven over a long time.

 

[cougar]

That I would not recommend. Loctite should not come anywhere near to plastic. It is either one or another. For props the locknuts are always safer option. All RC helicopters have locknuts on propeller pivot screws. Main blafes and tail. Always had. It is a common practice proven over a long time.

Here we go again, there is loc-tite that is not harmful to plastic!

 

[mmarian]

Here we go again, there is loc-tite that is not harmful to plastic!

It is not here we go again. The majority of people would go and buy the most common, readily available blue Loctite 243. And that is a big no no on plastic. If you want to educate people, point them to the right product instead of throwing a tantrum and acting like a smart Alec.

 

[cougar]

It is not here we go again. The majority of people would go and buy the most common, readily available blue Loctite 243. And that is a big no no on plastic. If you want to educate people, point them to the right product instead of throwing a tantrum and acting like a smart Alec.

Talk about smart Alec, you always do these kind of things.
Anyway may I introduce you to: Team Durango TD 390006 Thread Lock (used commonly among heli guys). Not harmful to plastic.

And by the way, the hubs are made of aluminum.

 

[mmarian]

Talk about smart Alec, you always do these kind of things.
Anyway may I introduce you to: Team Durango TD 390006 Thread Lock (used commonly among heli guys). Not harmful to plastic.

We could do here without the first paragraph...But for the sake of a good information provided, I am happy to swallow that personal insult

 

[cougar]

We could do here without the first paragraph...But for the sake of a good information provided, I am happy to swallow that personal insult

You started the name calling.

 

[mmarian]

You started.

If I may remind you, and for a record I did not. But if getting mad is needed for offering a good info, then that is fine by me.

 

[Florida Drone Supply]

Thanks. Still find it curious how it disengaged the nut even after backing the screw out so little if the locking ring is there.

We are sorry to hear about your loss of an Inspire 2 and camera. I will send you a PM to get more info and then post it if we agree to. I have 2 sets of T-Motor props in front of me right now, a very early set and a current set and both have nylon lock nuts embedded into the bottom of the prop hub which can not be seen without taking the prop assembly off the motor.

Look for a private message.

Jim

 

[mmarian]

We are sorry to hear about your loss of an Inspire 2 and camera. I will send you a PM to get more info and then post it if we agree to. I have 2 sets of T-Motor props in front of me right now, a very early set and a current set and both have nylon lock nuts embedded into the bottom of the prop hub which can not be seen without taking the prop assembly off the motor.

Look for a private message.

Jim

Thanks for providing that info. As with any accident or component failure we all try to get to the bottom of it. I believe that to solve the mystery of any accident is important for the safety of the operation and I certainly look forward to read about the findings and the final report on what might have caused this accident.

 

[tibook]

I have a set that I never got around to installing...didn’t have the tools handy the day I was gonna do the swap (silver lining perhaps?) do I need to get replacements before using?

 

[andoh666]

I still use the stock props for my I2. I've heard too many horror stories about 3rd party props failing and this story only cements my belief.

 

[mmarian]

@memmi
Wondering if you have managed to conclude the investigation and have arrived to any definitive finding, as to what caused the mid flight prop failure.

 

[memmi]

@memmi
Wondering if you have managed to conclude the investigation and have arrived to any definitive finding, as to what caused the mid flight prop failure.

Not yet, sent props back to FDS and hope to hear something definitive from them. I was utilizing a replacement pair of folding props this week at Burning Man with no issue.

 

[RotorWash]

i have removed my t motor props and gone back to std. I didnt see any advantages. In my experience, they dont like wind and the bird isnt as stable. Vibration was also an issue. Just my $2 worth.

 

[HeliEngadin]

Hello,
just to add our technical help on the point.
We do produce folding carbon fiber propellers for Inspire 1 and 2 from long before TMotor entered this particular market niche.
Our design for the Inspire 2 contemplates the use of nylon locknut embedded in the lower hub, but the most important part is the retaining spring washer on the top, just under the head of the screw.
That seemingly trivial part is the key in the joint, as it keeps a lot of constant force in the assembly, embedding itself into the contact surfaces (7075 aluminium hub and 10.8 steel screw), preventing any turning action not deliberatlely applied to the screw with a proper hex key.
In about three years of production, not a single customer had the propellers detach from the central hub, nor suffering functional structural damage in the carbon fiber.
Cosmetic scratches can happen, but they do not cause performance or safety issues; we do usually send replacements anyways.

We had a dozen reporting a collision with birds or crash into rocks, but in every case the folding props absorbed the impact and the rigidity of the carbon fiber permitted to the drone to come back home safely under its own flight ability.

We need to specify that our propellers are 100% carbon fiber, whereas competitor's one are resin infusion with some carbon layers added for strength.

Here attached are some detailed pictures of the aforementioned spring washer, and the others reinforcements embedded into the carbon fiber.



We hope this post didn't sound too much like advertising, but we felt there were some technical aspects to clarify.

Best regards,
HeliEngadin