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Old Apr 13, 2011, 01:07 PM
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Chinese fan blowing up, what are the chances....... I was thinking about geting one of these set up the way Knife has. Seems pretty solid that way.
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Old Apr 13, 2011, 01:35 PM
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Originally Posted by In N Out View Post
Chinese fan blowing up, what are the chances....... I was thinking about geting one of these set up the way Knife has. Seems pretty solid that way.
Interesting Avatar you got there!

EDIT: I'm not trying to bash your thread Lee and will delete my 2 cents if you like? Why send prayers to someone and continue to buy and support a product that may have destroyed a life of a fellow hobbyist? I'm a big fan of your guys work and respect what you guys do but, just don't make sense to me.
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Old Apr 13, 2011, 02:50 PM
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Interesting Avatar you got there!

EDIT: I'm not trying to bash your thread Lee and will delete my 2 cents if you like? Why send prayers to someone and continue to buy and support a product that may have destroyed a life of a fellow hobbyist?...
The motor?

The fan shroud?

The rotor?

Jus sayin,....
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Old Apr 13, 2011, 03:05 PM
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+1 on erh7771's comment. No need to start pointing fingers when we don't know what failed.

Failures happen even when using high-quality components. Unless an extensive investigation can be conducted, including testing to confirm the results of said investigation, we may never know the exact cause of the problem.

That was just a very unfortunate accident. This is a hobby that carries its share of risks, and I think we ought to learn from the experiences of others and help to improve, and make it safer and more fun.

Hope we all improve our testing environment regardless of what components we choose to use.


Get well Shep.
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Old Apr 13, 2011, 03:06 PM
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Why send prayers to someone and continue to buy and support a product that may have destroyed a life of a fellow hobbyist?
we are using these products in ways they werent intended for. its like saying "you wont buy a chev because your brother souped up a vett and got killed in an accident." its all part of the game. im sure hoaye would advise us not to run these things a 5kw. just my 2cents
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Old Apr 13, 2011, 03:34 PM
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Not trying to point fingers or piss on anyone's party, was just an emotional response.

Looking at the photo I doubt the motor was the cause of the failure? Kind of hard to diagnose the failure between the shroud or the rotor when it's laying there in shreds like pieces of paper. A chef isn't a good chef without having the proper ingredients to start with.
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Old Apr 13, 2011, 03:36 PM
Lee Liddle
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Originally Posted by knlken View Post
Interesting Avatar you got there!

EDIT: I'm not trying to bash your thread Lee and will delete my 2 cents if you like? Why send prayers to someone and continue to buy and support a product that may have destroyed a life of a fellow hobbyist? I'm a big fan of your guys work and respect what you guys do but, just don't make sense to me.
No problem. You have a right to your opinion. Here's my opinion.

It was an accident that happened while using the products in an experimental envionment. It's not the fault of any of the products or their producers. It's as simple as that.
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Old Apr 13, 2011, 03:43 PM
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for all we know, it was a fod issue.
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Old Apr 13, 2011, 03:46 PM
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No problem. You have a right to your opinion. Here's my opinion.

It was an accident that happened while using the products in an experimental envionment. It's not the fault of any of the products or their producers. It's as simple as that.
Sorry Lee, didn't mean to throw your thread off topic. Just don't want to see anyone of you guys get hurt next is all. You guys be careful!

Regards,
Ken
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Old Apr 13, 2011, 04:14 PM
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I agree CN. Could easily have been a FOD issue or plain and simple harmonic vibration at a particular rpm.
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Old Apr 13, 2011, 04:33 PM
Lee Liddle
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Sorry Lee, didn't mean to throw your thread off topic. Just don't want to see anyone of you guys get hurt next is all. You guys be careful!

Regards,
Ken
No problem Ken. The last thing I want to see is anyone getting a serious injury. I'm glad that Shep shared what happened with us. I have been very lax when testing fans. I hope everyone into edf will learn from it and be much more careful in the future.
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Old Apr 13, 2011, 05:37 PM
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I agree CN. Could easily have been a FOD issue or plain and simple harmonic vibration at a particular rpm.
I agree also. Talking about harmonic distortion or even Torque-induced precession has anyone tried to decouple EDFs from the airframe? A fairly firm rubber under the mounting flanges should dampen harmonics.
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Old Apr 13, 2011, 10:28 PM
John Green
USA, FL, St Petersburg
Joined Dec 2007
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As an observation of a possible scenario--- the Turbax rotor seems to be installed. I've read elsewhere on RCG that this rotor is not noted for it's balance. Some advocate leaving it off it's supposed to be so bad. At higher power levels an out of balance rotor could snag a bolt vibrated loose( judging from the direction of the bend in the bolt) causing the shaft to snap tossing the rotor into the shroud.
Like others here I like to experiment, and sometimes these experiments blow up. I bench with the lowest cell count the ESC will handle and save full power for in the plane and standing well back. This has saved me twice from potential injury. I like to think I do a thorough job of safety checking my setups and I've had some go, almost always using things beyond their design limits.
I think Lee has done a good job here, and George's adapter is solid. We all must just be more careful.
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Old Apr 14, 2011, 01:09 AM
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Joined Jan 2001
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The Turbax rotor itself is dynamically balanced so that is not an issue, of course cutting it down as we do for these setups means the operator needs to make sure it's balanced properly after sizing it to fit. The bigger problem is the Turbax spinner, it took me a while to get that one to fit and track good enough, a alu spinner like the ones Wemotec has on their Mini and Midi would be very nice, I wish JHH or anyone else could make one available.

Also, it's a good idea to start off slow when running a new fan on the bench, but IMHO you will also need to do full throttle runs on the planned cell count on the bench to make sure the fans is balanced properly and runs fine before putting it into a model. Otherwise how do you know if you don't have a resonance/vibration at certain rpm levels?
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Old Apr 14, 2011, 01:54 AM
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Balancing rotor

Hi everyone

I am starting to get a bit nervous since I have my mayden on my Falcon this saturday. I have tested the fan several times, but I haven't balanced the rotor after cutting it down How much balancing does it usually need after the cutting down?

It is the turbax cut down to 4.5"

And how did you do it?

When I tested the fan I was in another room. I have huge respect for these things but hearing about Sheppard made me reconsider if I want to maiden the bird at all

Thanks
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