How safe are carbon fibre props?

[MrTVR]

After a year of flying my I2 with the stock, wobbly, props I started to get very concerned. The aircraft would vibrate at certain prop speeds and looking end on, the tips of the props could be seen to flutter up & down quite violently.

I tried changing the props and the prop mounts several time but they all seemed to suffer the same issues.

Having read about the T-motor folding props from Florida Drone Supply I decided to give them a try.

They are not cheap but I have to say they have totally cured the vibration and prop flutter.

However, I have some questions and I would welcome your thoughts on the following:

1. Are carbon fibre props any more dangerous than the stock plastic props if they hit a person?

2. Will carbon fibre props be more reliable or less reliable than the plastic props?

3. What view would the CAA or FAA take of a drone operating with carbon fibre (none original equipment) props if it was involved in an incident?

4. Would the use of none standard props invalidate any insurance policy?

Looking forward to your replies ....

 

[The Editor]

After a year of flying my I2 with the stock, wobbly, props I started to get very concerned. The aircraft would vibrate at certain prop speeds and looking end on, the tips of the props could be seen to flutter up & down quite violently.

I tried changing the props and the prop mounts several time but they all seemed to suffer the same issues.

Having read about the T-motor folding props from Florida Drone Supply I decided to give them a try.

They are not cheap but I have to say they have totally cured the vibration and prop flutter.

However, I have some questions and I would welcome your thoughts on the following:

1. Are carbon fibre props any more dangerous than the stock plastic props if they hit a person?

2. Will carbon fibre props be more reliable or less reliable than the plastic props?

3. What view would the CAA or FAA take of a drone operating with carbon fibre (none original equipment) props if it was involved in an incident?

4. Would the use of none standard props invalidate any insurance policy?

Looking forward to your replies ....

1. Yes - they are like razor blades and tend to have a ‘sharper’ profile on the trailing edge.
2. No difference really with regards to reliability. However, CF props are far less forgiving in a collision and even a gentle nick against a tree limb etc can easily see a CF prop shatter.
3. As far as the CAA are concerned, they wouldn’t care. only that you were operating within your Ops manual remit and you had the requisite insurance. Heli flyers change out props, thrust bearings, servos, drive shafts, gearboxes, blades, linkages and more until the ‘stock’ machine is unrecognizable. Makes no difference to their insurance cover etc or how the CAA view them as flying models.
4. It shouldn’t do, providing the 3rd party props are specifically made for the aircraft in question. If your were experimenting with styles and profiles and mounts etc, then maybe your insurers (in the event of an incident) could get narky. However, unless there is some catastrophic injury to a person, they will not usually want to venture out of their air conditioned office so would never know and will just send you some forms to fill in and send back a cheque in settlement.

Hope that is of some help.

 

[MrTVR]

1. Yes - they are like razor blades and tend to have a ‘sharper’ profile on the trailing edge.
2. No difference really with regards to reliability. However, CF props are far less forgiving in a collision and even a gentle nick against a tree limb etc can easily see a CF prop shatter.
3. As far as the CAA are concerned, they wouldn’t care. only that you were operating within your Ops manual remit and you had the requisite insurance. Heli flyers change out props, thrust bearings, servos, drive shafts, gearboxes, blades, linkages and more until the ‘stock’ machine is unrecognizable. Makes no difference to their insurance cover etc or how the CAA view them as flying models.
4. It shouldn’t do, providing the 3rd party props are specifically made for the aircraft in question. If your were experimenting with styles and profiles and mounts etc, then maybe your insurers (in the event of an incident) could get narky. However, unless there is some catastrophic injury to a person, they will not usually want to venture out of their air conditioned office so would never know and will just send you some forms to fill in and send back a cheque in settlement.

Hope that is of some help.

Yes, excellent help, thank you.

It’s good to hear that the CAA wont be concerned as I really don’t want to have to go back to the rattly (and possibly dangerous) stock props.

Why ohh why can’t DJI design a better stock prop, or even, just go back to the design of the Inspire 1 props, which I have used for around three years without any issues.

 

[Florida Drone Supply]

After a year of flying my I2 with the stock, wobbly, props I started to get very concerned. The aircraft would vibrate at certain prop speeds and looking end on, the tips of the props could be seen to flutter up & down quite violently.

I tried changing the props and the prop mounts several time but they all seemed to suffer the same issues.

Having read about the T-motor folding props from Florida Drone Supply I decided to give them a try.

They are not cheap but I have to say they have totally cured the vibration and prop flutter.

However, I have some questions and I would welcome your thoughts on the following:

1. Are carbon fibre props any more dangerous than the stock plastic props if they hit a person?

2. Will carbon fibre props be more reliable or less reliable than the plastic props?

3. What view would the CAA or FAA take of a drone operating with carbon fibre (none original equipment) props if it was involved in an incident?

4. Would the use of none standard props invalidate any insurance policy?

Looking forward to your replies ....

Glad to hear the props helped clear all your issues. Thanks for giving them a try.

As for your other questions, we agree with the answers you got from the Editor above. If you have any more questions about the props or anything else, just ask.

Thanks!

 

[Florida Drone Supply]

All our customers in our flight school use the Florida Drone Supply T Motor carbon fiber props and are having great success with them.

Thanks @Steel_City, we appreciate your support!

 

[Phil DeVore]

I have been using the Tmotor folding winglet carbon fiber props for my I2 for about 6 months and I have had no problems with them whatsoever. I highly recommend them. They were purchased from Florida Drone Supply.

 

[VisualPoets]

Hey, let me throw in my two cents since I have actually hit things with CF and stock blades on my I2. Not proud of this but...I was flying with the Tmotor folding winglet carbon fiber props on the west coast near the ocean and was rising up when I caught a high tension power line (about 60' up) that I thought I was higher than. The I2 immediately lost all control and begin to wildly fall our of the sky. I quickly applied full throttle in hopes of something spinning up and slowing the fall and the inevitable gimbal bending crash. To my amazement the drone gained full control a couple feet above the ground and shot back up in the sky. Flight seemed stable. So without landing (stupid decision but felt pressure with director/producer of the movie I was shooting aerials for standing over my shoulder) I went back and shot 3 more takes of the scene. Then flew down the coast about 3 ft above the waves as they rolled in. Finally as battery neared the 30% mark I headed in for landing. Upon landing I discovered 3 of my 4 sets of blades cracked...2 severely. My belief is, the folding design allowed enough "give" and "fold" when hitting the power lines to absorb some shock. Then upon full throttle the blades spread back out to position and regained lift. I am positive the plastic props would have shattered and the craft would have come down destroying my X7 camera and 16mm lens. Plus to continue to fly the I2 with cracks just shows the strength of these blades. Since this, I have replaced all 4 with the same Tmotor folding winglet carbon fiber props.

 

[Phil DeVore]

As much as I hate to admit it I hit a tree branch with my I2 and I had the Tmotor winglet props on and it scared the b-Jesus out of me but to my amazement they actually chopped that 1 inch tree branch right into two pieces and kept flying! Upon landing I inspected the props and they didn’t have a scratch on them . I was near some power lines and they had scrambled my signal causing the I2 in active track mode to just go out of control and sending it into the tree. I’m a firm believer in those Tmotor props after that little incident!

 

[VisualPoets]

That's pretty amazing Phil! Glad you are still flying and didn't even have to replace them : )

 

[Phil DeVore]

That's pretty amazing Phil! Glad you are still flying and didn't even have to replace them : )

Yes it blew me away that they survived the incident! Just goes to show you how well they’re built. And I will continue using them for my I2. Thanks for the reply .

 

[Florida Drone Supply]

As much as I hate to admit it I hit a tree branch with my I2 and I had the Tmotor winglet props on and it scared the b-Jesus out of me but to my amazement they actually chopped that 1 inch tree branch right into two pieces and kept flying! Upon landing I inspected the props and they didn’t have a scratch on them . I was near some power lines and they had scrambled my signal causing the I2 in active track mode to just go out of control and sending it into the tree. I’m a firm believer in those Tmotor props after that little incident!

Please give the props another look or two, after contact with something we strongly urge lots of caution. You may want to use a magnifier to inspect the props after a prop strike.

 

[Phil DeVore]

Please give the props another look or two, after contact with something we strongly urge lots of caution. You may want to use a magnifier to inspect the props after a prop strike.

Thanks and I already looked at them with a magnifying glass and found no cracks or other issues with them.

 

[MrTVR]

VisualPoets & Phil DeVore thank you for sharing your experiences with the T-motor folding props. It’s reassuring to know that they stand a good chance of surviving a hit and allowing the I2 to land safely. I’m slightly alarmed that they chopped through a 1 inch tree branch without even showing any signs of damage!

 

[Phil DeVore]

VisualPoets & Phil DeVore thank you for sharing your experiences with the T-motor folding props. It’s reassuring to know that they stand a good chance of surviving a hit and allowing the I2 to land safely. I’m slightly alarmed that they chopped through a 1 inch tree branch without even showing any signs of damage!

Me too

 

[Phil DeVore]

Me too

I may have exaggerated the size of the tree branch by a little bit but it was at least 1/2 inches in diameter and it was still impressive that it didn’t have any noticeable damage to the props.

 

[MrTVR]

I may have exaggerated the size of the tree branch by a little bit but it was at least 1/2 inches in diameter and it was still impressive that it didn’t have any noticeable damage to the props.

Slightly less worried now ...

 

[2B-Inspired]

Slightly less worried now ...

1/2 as worried?

 

[MrTVR]

1/2 as worried?

Or maybe 1/(pie squared) as worried [emoji23]