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Old Jul 26, 2010, 10:48 PM
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Now if we could just get that video tutorial for the rest of us "dumb dumbs!" ...hehe
Sergey.... hint, hint;-)
Z
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Old Jul 26, 2010, 11:03 PM
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I think have found an issue to be aware of. As far as I can ascertain, getting reliable data has a great deal to do with working with constants. Sergey's method ensures all factors with the exception of 2.

1. Spool up and spool down of EDF. It is a manual factor at this stage. Is it of vital importance? I'd like some feedback please from those in the know.

2. Something else I have found... The shaft adapter between motor and impeller.

I have had issues with the adapter turning on the motor shaft (when change degrees of impeller for next reading) of my Freewing 70mm EDF that came with my F16. I have noticed that it doesnt run straight sometimes but if I turn it so it runs true, it does not vibrate excessively. This problem will be interfering with readings. I guess a drop of CA on the shaft would fix this problem. If I need to remove the adapter a quick zap with a soldering iron weakens the glue.

I see evidence of this from the 3 sets of data I have recorded. Each set has a different low point. I put this down to the cheap adapter supplied with the motor.

Anybody else found this?
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Old Jul 26, 2010, 11:16 PM
Debris Fields 'R' Us
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Union City, Ca
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Yes, I would agree with your finding. I was able to repeat with enough reliability to satisfy me.
I realize that I won't be able to get the result that proper equipment is capable of, but the advantages of this process will enhance the performance and longevity of the power system.
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Old Jul 26, 2010, 11:31 PM
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For windows mobile users Seismometer (look for SeismoCAB.cab) might give reading even though it doesn't output to a csv...

The point is to find the spot on the rotor while it's attached to the motor that gives the least amount of vibration.

This thread is gets my vote for sticky of the year so far...a balanced rotor = more power and more realistic sound IMHO
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Old Jul 26, 2010, 11:47 PM
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Gold Coast, Australia
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Quote:
Originally Posted by Quicksdraw View Post
Yes, I would agree with your finding. I was able to repeat with enough reliability to satisfy me.
I realize that I won't be able to get the result that proper equipment is capable of, but the advantages of this process will enhance the performance and longevity of the power system.
I wasnt suggesting that it was a bad system. Its brilliant!! I was just saying to be aware of the pitfalls of cheap EDF equipment that can effect the outcome.

I had a hell of a time TBO because of the shaft adapter turning and using the wrong data from the CSV. The upside is I have found out stuff that will help future readers.

What I find funny is that even though things didnt go exactly as they were supposed to per the "Sergey Method", I still had an EDF that is way better than standard. My F16 vid was rated as "spooky" on the F16 thread due to its low noise. lol

Now that I have found my own issues and how to correct them I am going to apply them and see how much better I can get my fan.
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Old Jul 27, 2010, 12:42 AM
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Yes, I'm sure that there is room for improvement with a little more effort. Don't get me wrong. I just chuckle at what we can do with what I now consider standard household products and a few spare minutes.
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Old Jul 27, 2010, 12:52 AM
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Yes, I'm sure that there is room for improvement with a little more effort. Don't get me wrong. I just chuckle at what we can do with what I now consider standard household products and a few spare minutes.
It is truly amazing isnt it? Its not just isolated to using a smart phone here either. The iPod Touch can be used also.

Bring on technology!!
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Old Jul 27, 2010, 08:27 AM
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It is truly amazing isnt it? Its not just isolated to using a smart phone here either. The iPod Touch can be used also.

Bring on technology!!
Can't wait till Sergy gets done experimenting with the contact mike, it measures vibrations too but we don't have to use a cell phone to perform the dynamic balancing just the mike and a laptop...

My first edf caused me to plug an ear...bring on the turbine sounds!
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Old Jul 27, 2010, 09:00 AM
Ugly planes do not fly
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Originally Posted by Quicksdraw View Post
I just did a new setup for an E-Flite F-86.

IMPRESSIVE results using the Vibration App on the iPod Touch.

My final position reads 1/10 of the highest measured position.

Sergey, thanks for a clear explanation of this process. This ROCKS
You are very welcome! Glad it works!
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Old Jul 27, 2010, 09:15 AM
Ugly planes do not fly
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Originally Posted by Fubar69 View Post
1. Spool up and spool down of EDF. It is a manual factor at this stage. Is it of vital importance? I'd like some feedback please from those in the know.
You are absolutely correct. This is a variable. There are at least three ways to improve precision:
a) Try to be as consistent as possible. Count 1001, 1002, 1003 on the throttle up and down. Still not the best.
b) Average measurements. Using a) measure three to five times and average result. Better but time consuming.
c) I am working on a software that will automate this process. The program will run EDF and collect data. This will minimize human error.

Quote:
Originally Posted by Fubar69 View Post
2. Something else I have found... The shaft adapter between motor and impeller.
Rotating impeller may be not convenient or even possible. There is an alternative method on the first post describing balancing process without disassembling EDF. Hope it will resolve adapter issue.
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Old Jul 27, 2010, 09:18 AM
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Originally Posted by erh7771 View Post
Can't wait till Sergy gets done experimenting with the contact mike, it measures vibrations too but we don't have to use a cell phone to perform the dynamic balancing just the mike and a laptop...

My first edf caused me to plug an ear...bring on the turbine sounds!
I got my mike yesterday and software is 30% ready. Should have some results by the weekend.
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Old Jul 27, 2010, 12:34 PM
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Caution

Some accelerometers equipped devices also have hard drives in them, such iPods. It is probably not a good idea to subject a hard drive to a vibration levels EDF creates. This can destroy a hard drive.
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Old Jul 27, 2010, 04:16 PM
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I got my mike yesterday and software is 30% ready. Should have some results by the weekend.
Much respect if you're writing an app for this...
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Old Jul 27, 2010, 04:42 PM
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United States, FL, Daytona Beach
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Ipods

I thought the new Ipods had Flash drives. I will check it out .
Thanks
For the notice before I spent money
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Old Jul 27, 2010, 06:01 PM
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Gold Coast, Australia
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Originally Posted by _Sergey_ View Post
I got my mike yesterday and software is 30% ready. Should have some results by the weekend.
Are you writing it in C or something? I'm a Linux systems engineer by profession.
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