Critical Failure of T*Motor Props during shoot

[memmi]

Firstly let me state my positive experience with the T*Motor Folding Props for Inspre 2. I’ve used the folding T*Motor props actively since their release. I’ve appreciated the speed at which I can deploy the inspire from the LowePro drone guard pack and traveled from Tulum to Iceland and beyond using this combination. I also want to acknowledge Florida drone supply as a responsive retailer and active partner in this space.

In Brooklyn last weekend was flying the X7 for a shoot at a densely populated large scale venue at night (with applicable night waiver). Our 5th flight, around midnight, launched from a protected elevated platform. Immediately after launch a loud crack was heard and from about 6 feet above launch elevation the inspire went spiraling into the ground breaking the rear leg motor mount housing and all remaining props and the Imaging system on the Inspire 2.

Upon inspection one of the props cracked and sheared off from its pivot. The ejected half was not recovered. I constantly check the torque on both the prop bolts and the motor bolts and they were all appropriately torqued. There were no prior collisions or damage to the props, the full set was under 2 months old.

As it stands I appreciate the performance and convenience of the T*motor props and was looking forward to active use during Burning Man this year. However, I wanted to communicate my experience as a data point and a warning that as far as I can tell, the t-motor props under normal use have the potential for catastrophic failure.

I'm open to input and would like to hear if this is an isolated incident or if there are other similar issues. Am I wrong to no longer trust this product?

Video of the shoot at:
Mayan Warrior (@_mayanwarrior_) • Instagram photos and videos

 

[memmi]

Sheared Prop

 

[memmi]

Damage to Inspire

 

[slim.slamma]

DAT files? Could have your answers

I'm open to input and would like to hear if this is an isolated incident or if there are other similar issues. Am I wrong to no longer trust this product?

 

[memmi]

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Here's the flight log.

 

[PortCanaveralFlorida]

Firstly let me state my positive experience with the T*Motor Folding Props for Inspre 2. I’ve used the folding T*Motor props actively since their release. I’ve appreciated the speed at which I can deploy the inspire from the LowePro drone guard pack and traveled from Tulum to Iceland and beyond using this combination. I also want to acknowledge Florida drone supply as a responsive retailer and active partner in this space.

In Brooklyn last weekend was flying the X7 for a shoot at a densely populated large scale venue at night (with applicable night waiver). Our 5th flight, around midnight, launched from a protected elevated platform. Immediately after launch a loud crack was heard and from about 6 feet above launch elevation the inspire went spiraling into the ground breaking the rear leg motor mount housing and all remaining props and the Imaging system on the Inspire 2.

Upon inspection one of the props cracked and sheared off from its pivot. The ejected half was not recovered. I constantly check the torque on both the prop bolts and the motor bolts and they were all appropriately torqued. There were no prior collisions or damage to the props, the full set was under 2 months old.

As it stands I appreciate the performance and convenience of the T*motor props and was looking forward to active use during Burning Man this year. However, I wanted to communicate my experience as a data point and a warning that as far as I can tell, the t-motor props under normal use have the potential for catastrophic failure.

I'm open to input and would like to hear if this is an isolated incident or if there are other similar issues. Am I wrong to no longer trust this product?

Video of the shoot at:
Mayan Warrior (@_mayanwarrior_) • Instagram photos and videos

"similar issues" as for ALL CF props there is an issue with a slight chip/crack, even small rocks/pebbles that hit the prop (and they will)
go unnoticed. High RPMs - and prop will shatter like a bomb! If you have the budget, replace them ASAP when found @ $$$ each.
@ say $10 the plastic props have NEVER failed me, never! The performance of the CF is very minimal compared to the plastic props, tho the ego of having them on the bird is another story.

I'll take the plastic props any day of the week and place the saved funds in my righthand pocket! That's just me... and there is no way I would place those remaining props back on the bird. Stress cracks, a chip, you name it! Nope-nada-no way! As I'm looking at the pic, this could have been the Oh-Sh*t of the motor mounting issuse that's been plaguing the i2 also.

 

[slim.slamma]

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[dioriosigns]

same here went back to stock props, T motor props not solid carbon fiber .

 

[MrTVR]

I am curious, how can you be certain that this was caused by a prop failure?

One danger of night flying is bat or bird strike, which you are unlikely to see in the dark ...

 

[slim.slamma]

I am curious, how can you be certain that this was caused by a prop failure?

Likewise


The only thing I can say is that’s an industrial area, trucks, trucks, trucks.
High overhead clearance.

It’s is hard to comprehend the prop just going boom unless the bolts was over tightened.

Inspection inspection inspection

 

[NickU]

If he'd hit a bird or bat, I'd have thought the prop root with the remains of the blade would still have been present on the central hub at the hinge shaft whereas it's completely missing in the photo he's showing.

Sorry for the loss of the camera and the damage to the I2... it leaves a sad feeling picking up the bits , but on a brighter note, at least it didn't hit or injure anyone

 

[memmi]

If he'd hit a bird or bat, I'd have thought the prop root with the remains of the blade would still have been present on the central hub at the hinge shaft whereas it's completely missing in the photo he's showing.

Sorry for the loss of the camera and the damage to the I2... it leaves a sad feeling picking up the bits , but on a brighter note, at least it didn't hit or injure anyone

100% not a bird strike it was at eye level and we had 3 eyes on it. Our area was lit and the drone was visible.

Not overtightened either as my pilot lectured me about that previously and I became ocd about the tension on the blade bolts. They were all perfectly torqued.

Nick, i’d Happily replace 100 inspires before contemplating that scenario. It was literally a coin toss and it could have flipped the opposite direction to a densely poulated area of the club a floor below.

 

[Dobmatt]

100% not a bird strike it was at eye level and we had 3 eyes on it. Our area was lit and the drone was visible.

Not overtightened either as my pilot lectured me about that previously and I became ocd about the tension on the blade bolts. They were all perfectly torqued.

Nick, i’d Happily replace 100 inspires before contemplating that scenario. It was literally a coin toss and it could have flipped the opposite direction to a densely poulated area of the club a floor below.

Memmi, there's really not much to contemplate about your unfortunate accident. Two words: s...t happen. I'll be far from concluding that T-props are badly designed or manufactured. Things get broken and there's nobody to blame.

 

[cougar]

100% not a bird strike it was at eye level and we had 3 eyes on it. Our area was lit and the drone was visible.

Not overtightened either as my pilot lectured me about that previously and I became ocd about the tension on the blade bolts. They were all perfectly torqued.

Nick, i’d Happily replace 100 inspires before contemplating that scenario. It was literally a coin toss and it could have flipped the opposite direction to a densely poulated area of the club a floor below.

Very interested to know what torque value they where adjusted to and what tool you where using? Thank you.

 

[memmi]

Memmi, there's really not much to contemplate about your unfortunate accident. Two words: s...t happen. I'll be far from concluding that T-props are badly designed or manufactured. Things get broken and there's nobody to blame.

I think your misunderstanding my intention. I don’t wish to place blame. Only understand if this is an isolated or more common occurrence and add an anecdotal datapoint that others could reference as well.

Said in your terms “has this same **** happened to others and might this same **** happen again?”

 

[mmarian]

I think your misunderstanding my intention. I don’t wish to place blame. Only understand if this is an isolated or more common occurrence and add an anecdotal datapoint that others could reference as well.

Said in your terms “has this same **** happened to others and might this same **** happen again?”

I do not use Tmotor props. I use the original ones. Despite some of the shortcomings in terms of fit and loose tolerancies or not ideal design of the mount I have had zero issues after a year of flying. I did the cyanoacrylate mod and use tape over the motor mount block to make the fit nice and snug. But none of these parts, DJI or third party are individually and scientifically tested for material faults and potential imperfections during manufacturing process. To expect that level of scrutiny would increase the price exponencially. So to some extent it is a lack of draw to get a bad apple, so to speak. Let's hope that this is an isolated incident but I'd understand if it would have left a dent in confidence in this particular product in you...

 

[lake_flyer]

I still use the old (plastic) screw on props on my I1.
Simple, effective, reliable, safe.

 

[Mike Lazzar]

same here went back to stock props, T motor props not solid carbon fiber .

I could never justify the cost of CF props for my I1v2. Wallet is just not deep enough. I'm def. not familiar with construction of T-Motor props but having flown different helis up to 500s I can say that I've never seen a solid CF prop. They are usually constructed with CF outer shell/layers sandwiching a foam inner. The forces put on a 500 size heli props are way more stressful than on an I1 and they hold up extremely well. But if you do have a chip or crack in the CF you are taking a risk of the prop delaminating and blowing apart midflight.

 

[Alexandre Brazil]

Failures unfortunately happens.....
Maybe a parachute system saves the day.
Take a look on Parazero website.

 

[ElectricLife]

This is why we tried to fix the motor mount and propellers as an all in one solution.
We did not try to make CF props, as we think they're too rigid to begin with (Potential for vibrations) and potentially fragile (CF can explode or shatter).
CF would have been the easy solution...We made several 3D printed prototypes with a mix of aluminum, carbon fiber, fiberglass, but none of them are rigid enough (3D printing sucks in this case). The way to go is the classic molds, but at the same time it's a project too expensive to justify, given the fact that nobody has any idea of how many I2s have been sold. We're talking about 7 to 10k for a proper, non Chinese job.
It's a pity, because the re-design of the motor mount + props seems solid and fits perfectly the motor, while preventing the dreaded rattle and the props, according to the University of Pisa's supercomputer and engineers, are 13.7% more efficient than DJI's original ones. It would have been a win/win situation. These are the potentially perfect props but they will never see the light of day because of a lack of enough I2s to make it a financially viable project. Sigh! Maybe we should send all the engineering work to DJI.