Broken props

[Kilby]

Hey guys,

I had a small crash today am I'm trying to figure out the cause. Luckily I didn't do much damage, but obviously I want to try and avoid the same mistake twice. My question is, have any of you had problems with props breaking mid flight without any type of impact or extra strain of any kind? I had APC Slow flyer 10x4.7's on and I had been using them for a pretty long time (few months). During the post crash inspection I noticed that one of the props broke in half and lost one of the blades. Know I'm trying to figure out if that was the cause of the crash, or one of the casualties. It had just started to sprinkle a tiny bit and I'm also suspect that my CopterControl had a rain drop hit it and caused it to bug out. I'll be flying again soon either way, but just curious if anyone else has had this problem.

-Terry

 

[mbsteed]

A rain drop probably is not the cause. Fatigue might be an issue. When I was working with my Gaui the original suggestion was to use locktite on the prop adapters to keep the nut on because there was so little thread left for the nut. However, folks quickly discovered that the locktite was weakening the plastic of the props. I had one split right down the middle of the hub and you could see how the locktite had impregnated the plastic. Perhaps you got something on the prop that caused it to weaken ...or just a bad prop.

 

[RTRyder]

I've had Gaui and EPP props throw a blade in flight either from fatigue or maybe having been previously stressed in an "unintended landing event". Last one I had that happen to was in a fast high G turn, guess it was just a little too much stress on the blade, it made a weird popping sound and then did a diagonal wobble to the ground.

Ken

 

[Bartman]

i wonder if the weird popping sound was it flexing and hitting the frame before it broke.

 

[Kilby]

I've actually heard reports from other CC users that a water drop can cause it to go crazy, that's why I mentioned it. I'll have to see if I can find that post again. It just seemed like very odd timing that it happened the exact same moment that it started to sprinkle. Luckily I was bringing it in because of the rain and only dumped it from a few feet up.

 

[Jake Bullit]

I had an APC 10X 4.7 break midflight a couple of weeks ago.Fortunately I was low down over long grass at the time so no damage was done.
The prop had probably been on for some time so there is a good chance it might have suffered some impact in the past ,but not enough to break it.

 

[Kilby]

I tried to find the post I mentioned above and I think I was actually thinking of a user of the Paris board. Either way I think the new plan is be sure and change my props regularly and get some kind of cover for the FC to keep dust & moisture away from it. I'm starting a new quad build later today so I'll implement this plan there first.

The only funny thing about the prop break though was the fact that it broke at the thickest part. I would assume that to be the strongest and the reason I was thinking it broke on impact rather than in the air.