I have a set on my Inspire 2 and upon hearing your experience it concerns me as well. I too constantly check the torque of the mounting system before each and every flight. I’m very alarmed by your bad experience with the Tmotor propellers and I hope this is an isolated case. Also I want to say how sorry I am to hear of all the damage that you received during this incident.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
Phil, you mention that you check the torque before every flight, checking the torque value to me implies the use of a calibrated tool, what value are you checking? Are you just checking the props are snug or do you actually have a specific value that they are tightened to?I have a set on my Inspire 2 and upon hearing your experience it concerns me as well. I too constantly check the torque of the mounting system before each and every flight. I’m very alarmed by your bad experience with the Tmotor propellers and I hope this is an isolated case. Also I want to say how sorry I am to hear of all the damage that you received during this incident.
Phil
Very good advice for the Tmotor props as far as being watchful of how I need to be when folding them up for transport. I’ll definitely be taking your comments seriously.Sounds like good input and strong feelings on both sides. Here is our personal experience and what we’re doing. Must admit I still have a slight lump in my throat on many of my flights (often over water) reguardless of prop choice, maintenance, battery checks, etc. I’ve flown too many years/hours to know that something can always go wrong (and pilot error is my BIGGEST concern). I was flying a few weeks ago on the coast in Malibu for a movie. Using the I2 & X7. My shot called to rise away from the coast and reveal the ocean. It was the 4th take as the director wanted something slightly different each attempt. I saw the high tension power lines back high above me but on this attempt, simply misjudged my height in relationship to them. I came into contact with the power line which then tossed the I2 to spin resulting in other props hitting the line. Of course the bird began to fall wildly out of control toward a large tree below. In a seemingly vain attempt I applied full throttle and the I2 righted itself in flight! It hovered correctly. After flying it all the way back to us, I landed and to my amazement 3 of the 4 props were severely damaged. Large cracks and tears. I believe the fact that the props fold, allowed them to “give” somewhat upon impact, and when I throttled back up, they unfolded to their flight positions, thus maintaining flight. Not having 3 full sets for replacement, I replaced them with the stock plastic blades. 2 weeks later we were flying attitude mode in the underground limestone caves of Louisville for a commercial job when we came in contact with a small hanging wire from the cave’s ceiling. The dangling wire instantly sheared the plastic prop and the I2 fell 30’ to a rock floor cracking 2 legs and damaging the brain and X7. I wonder if the folding props might not have “given” a little upon impact and then regained flight upon throttle up as in Malibu. Reguardless, all plastic props have now been replaced back with T-M folding props. In the numerous flights since we’ve had no incidences. NOTE: I have noticed that if you carelessly fold these props in a hurry, that they will hard stop and contact the shaft housing itself on the prop. Over time this does and will create a dent in the blade which I believe could compromise the blade in flight. Be sure to always fold each half the blade perpendicular the the shaft housing connector so the blade is not in contact with the aluminum stop. That’s my experience. Anyone else hit something with folding props and lived to fly again because they folded on impact?
...
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.....
Mayan Warrior (@_mayanwarrior_) • Instagram photos and videos
You needed a waiver to fly over people AND I doubt you would've gotten if for that many people. Glad your prop breaking didn't happen over that crowd.
Phil, you mention that you check the torque before every flight, checking the torque value to me implies the use of a calibrated tool, what value are you checking? Are you just checking the props are snug or do you actually have a specific value that they are tightened to?
I asked the same question of the OP since he also mentioned he "checked the torque", but he did not respond. Maybe he missed my question.
No I don’t have a calibrated tool I simply check them for a snug fit. Before each flight I just check to make sure that the mounting screws are tightened up. It’s more of a feel than anything else. I hope that answers your question??Phil, you mention that you check the torque before every flight, checking the torque value to me implies the use of a calibrated tool, what value are you checking? Are you just checking the props are snug or do you actually have a specific value that they are tightened to?
I asked the same question of the OP since he also mentioned he "checked the torque", but he did not respond. Maybe he missed my question.
Thank you Phil, yes that answers my questions. Was hoping that someone actually had a torque value for setting the props.No I don’t have a calibrated tool I simply check them for a snug fit. Before each flight I just check to make sure that the mounting screws are tightened up. It’s more of a feel than anything else. I hope that answers your question??
When I first installed them I was told by Florida Drone Supply that they came tighter than they should be from the manufacturer and they told me to loosen them to where they were going to unfold without any trouble. I check this each time before I fly also just to be sure that everything is as good as possible to try to avoid any problems while up in the air. Once again I hope I have answered your questions.
Yes you would think that the manufacturer would provide a torque setting that we could use to make sure we had a proper torque value on the mounting screws but oh well. I guess they figure it isn’t a big deal. But then we would need some kind of torque wrench for them and that would be a hard thing to find I would imagine. Does someone make a torque wrench that small? I haven’t got a clue? If you have any ideas on where to find something like that please let me know. I am interested in finding one.Thank you Phil, yes that answers my questions. Was hoping that someone actually had a torque value for setting the props.
I find it very strange that neither the manufacturer or the distributor, has any public torque value that they recommend. Since that seems to be the only reliable way to adjust the tension on the props.
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.
View attachment 20697
Guys I think you are making too much of a deal of this. I know that there are users with natural feel for mechanical things and then there are those with not so much. But honestly this is not so complicated. As I said I do not have these props but I have been flying RC helis for years and both tail props needed to be tighten equally and optimally. Not too tight and not too loose. They both needed to outstretch with centrifugal force to optimal position to avoid vibration. As I said it is all about feel. No amount of torque info can replace that.Yes you would think that the manufacturer would provide a torque setting that we could use to make sure we had a proper torque value on the mounting screws but oh well. I guess they figure it isn’t a big deal. But then we would need some kind of torque wrench for them and that would be a hard thing to find I would imagine. Does someone make a torque wrench that small? I haven’t got a clue? If you have any ideas on where to find something like that please let me know. I am interested in finding one.
I agree with you that people are making this issue way too complicated. It’s simply a matter of feel when you’re tightening the props. Kinda like when you’re replacing your tire after having had a flat. Just don’t strip the lugs when you’re tightening them down. Same idea here too.Guys I think you are making too much of a deal of this. I know that there are users with natural feel for mechanical things and then there are those with not so much. But honestly this is not so complicated. As I said I do not have these props but I have been flying RC helis for years and both tail props needed to be tighten equally and optimally. Not too tight and not too loose. They both needed to outstretch with centrifugal force to optimal position to avoid vibration. As I said it is all about feel. No amount of torque info can replace that.
That would be interesting, you can send us a PM, if you like. We just spoke to a friend that works in automotive and they might have the right tools for making an aluminum test run prop. We do really like the idea of making them as one single element, rather than a mixed materials & parts propeller. The aim is to have a no brainer prop with some proven added benefit that also fixes the mount. Basically a set it and forget it prop, just like DJI's, only without the well known mount flaw and with the extra bonus performance.Wow, extraordinary. I might have a contact for you if you’d like to explore that option.
Now I agree with you but don’t you think that they would be extraordinarily expensive!! And DJI would throw a fit if you ever had to send your Inspire 2 in for repairs. Would definitely void the DJI Care Refresh program.That would be interesting, you can send us a PM, if you like. We just spoke to a friend that works in automotive and they might have the right tools for making an aluminum test run prop. We do really like the idea of making them as one single element, rather than a mixed materials & parts propeller. The aim is to have a no brainer prop with some proven added benefit that also fixes the mount. Basically a set it and forget it prop, just like DJI's, only without the well known mount flaw and with the extra bonus performance.
Guys I think you are making too much of a deal of this. I know that there are users with natural feel for mechanical things and then there are those with not so much. But honestly this is not so complicated. As I said I do not have these props but I have been flying RC helis for years and both tail props needed to be tighten equally and optimally. Not too tight and not too loose. They both needed to outstretch with centrifugal force to optimal position to avoid vibration. As I said it is all about feel. No amount of torque info can replace that.
As I said before I would appreciate the manufacturer to provide a recommended torque value for the Tmotor props but they didn’t so I just do the best I can with what’s available to me and that’s by the feel of the tightness of the propeller mounting screws. Although I am going to take your advice and look on Amazon for a miniature torque wrench. That way I can at least get the screws tightened to the same setting. I don’t know if it’ll make any difference but it’s worth a try.I think I have to disagree with this simplistic thinking, you are referring to a heli that has one router and normally 2 blades. The I2 has 4 motors and 8 blades, if they are not tourqued the same, introduces unbalance and potential vibration.
Yes some people does have a great feel and others might not, having said that I still think a recommended torque value would be the way to go. I can also confirm that the props are already pre-tourqued to a specific value when delivered, they are all the same.
As for tools, there is miniature torque drivers available on Amazon.
Phil, look for a tool that has the range of 5 - 60 cN.m, anything larger would probably not have the accuracy for this size of screws and torque. I can tell you that the props come from manufacturer set to 50 cN.mAs I said before I would appreciate the manufacturer to provide a recommended torque value for the Tmotor props but they didn’t so I just do the best I can with what’s available to me and that’s by the feel of the tightness of the propeller mounting screws. Although I am going to take your advice and look on Amazon for a miniature torque wrench. That way I can at least get the screws tightened to the same setting. I don’t know if it’ll make any difference but it’s worth a try.
Now I agree with you but don’t you think that they would be extraordinarily expensive!! And DJI would throw a fit if you ever had to send your Inspire 2 in for repairs. Would definitely void the DJI Care Refresh program.
But if they were affordable to the average person they would be awesome! Count me in if the price is right!!
There are other variables at play. The ease of move can be affected by smoothness of the surface of the props and the internal surface of the fork where the prop goes to. Tiny amount in any of such variation or tiny burr on the internal edge or a bit of finger grease can change the equation. And from experience the force required to move the prop in the fork can vary with angle too. So, what I am trying to say is that feel might be in this instance more reliable indicator of the proper screw tightness than the torque applied to the screw. The same torque might not necessarely result in the same stiffness of the prop in the fork. The only scientific approach would be to measure the force required to move the prop at a specific distance from the pivot screw. But that is a another thing altogether. Because of all the above I have never been a fan of foldable props on MC.I think I have to disagree with this simplistic thinking, you are referring to a heli that has one router and normally 2 blades. The I2 has 4 motors and 8 blades, if they are not tourqued the same, introduces unbalance and potential vibration.
Yes some people does have a great feel and others might not, having said that I still think a recommended torque value would be the way to go. I can also confirm that the props are already pre-tourqued to a specific value when delivered, they are all the same.
As for tools, there is miniature torque drivers available on Amazon.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?