Carbon Fiber Props Deteriorating ~ Failing

[R_Lefebvre]

I don't think that's why DJI did that, because the hinge on those props is not in the right direction. What you would need is more like a folding glider propeller. Or, a teeter-totter design which is what most RC helis use.

 

[PeterLester]

Yes I understand now...... one needs to adjust each blade pitch to eliminate the torque you are talking about....... but the only way to do that is with the collective pitch concept.......... and that adds far too much complexity to a MR!!!!

I don't think that's why DJI did that, because the hinge on those props is not in the right direction. What you would need is more like a folding glider propeller. Or, a teeter-totter design which is what most RC helis use.

 

[R_Lefebvre]

No, you don't need collective pitch control, you just need a very simple pivoting hinge point. Yes, it's extra complexity on a MR, and I'm not really suggesting it's worthwhile to pursue. It was just a statement that this could be a cause of the failure of these CF props, and also that it's important to understand then is occurring when designing a multirotor vibration control strategy.

 

[SleepyC]

I have had good and bad luck with the 15/5 RCTimer "T-motor' clone props.
This is a pic of one new from the package. I just do a quick NON-destructive flex test to listen for any weird noise. This prop squeaked.
After close inspection I found a crack near the hub which lead to an area of delamination. (highlighted in red)
View attachment 14179View attachment 14180



ALSO: For the record. The REAL T-motor props are SICK. Worth every penny. I slapped them on my Hex and it was flawless. So smooth.
I treat those props like my children, they get tucked into their included sleeping bags after every use. SO NICE!!

 

[R_Lefebvre]

Well, I just ordered 16 APC MR props. Not going to chance it with these cheap CF props.

 

[jes1111]

No, you don't need collective pitch control, you just need a very simple pivoting hinge point. Yes, it's extra complexity on a MR, and I'm not really suggesting it's worthwhile to pursue. It was just a statement that this could be a cause of the failure of these CF props, and also that it's important to understand then is occurring when designing a multirotor vibration control strategy.

Have you seen this thesis - http://www.eng.yale.edu/pep5/P_Pounds_Thesis_2008.pdf ? - he built teetering hubs but IIRC they didn't work well. (mind you, IMHO nothing on that project worked well )