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Old Sep 10, 2012, 07:52 PM
EDF rules... :)
AirX's Avatar
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Quote:
Originally Posted by M3ATpl0w View Post
I know sarcasm is easy to miss on forums...

This has been an awesome thread for me. Been flying a while, and love jets, but hated the shrill noise made by the old edfs. This fan is the reason I now have a jet. I have followed since day 1, and I am constantly amazed by the knowledge and cleverness a lot of you guys have. And your willingness to share is awesome in my eyes.
Sorry, wasnt directed at you.
The 6 I have work fine with cheap motors where I dont worry about high power. I have a Velocity T45 that I want to put a 5s version in for the same reasons you like the CS70...
I might have to get the parts from Tamjets to get this one going.

Eric B.
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Old Sep 10, 2012, 07:58 PM
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rfodor.... you said "flys for about 4 minutes (mostly at 1/2 throttle)"....
There is your answer.
"Jet sound" comes from white noise... which comes from airflow 'difficulty'. Passing over odd surfaces, angles, edges, being restricted etc.
So to have that occur it needs 'airflow'. So imagine you BLOW air down the ducting yourself... that will be a pretty weak amount and speed!! LOL NO white noise.... (very minor, if any).
This is what your "1/2 throttle" does.....

The more RPM/thrust... the higher the airflow... the more white noise, due to the "duress" that higher airflow has then.
If you have little white noise, "jet" sound.... you have airflow that is too 'clean'. A Habu has a very 'clean' ducting system. The only way to get white noise from that situation is to have a LOT of airflow that "over-drives" its 'cleaness".
You have to choose between performance optimals, and sound optimals.

You also mentioned the take-off 38k RPM, and good sound...... again there is your answer.
More airflow duress... thus more white noise then.
So to get the sound, just as the plane is... fly WOT all the time! LOL
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Old Sep 11, 2012, 08:41 AM
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Off topic..sort of

Did you guys see this bad boy?
http://hobbyking.com/hobbyking/store...dproduct=27559

Looks sweet...anyone try it yet?
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Old Sep 11, 2012, 05:21 PM
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Quote:
Originally Posted by PeterVRC View Post
rfodor.... you said "flys for about 4 minutes (mostly at 1/2 throttle)"....
There is your answer.
"Jet sound" comes from white noise... which comes from airflow 'difficulty'. Passing over odd surfaces, angles, edges, being restricted etc.
So to have that occur it needs 'airflow'. So imagine you BLOW air down the ducting yourself... that will be a pretty weak amount and speed!! LOL NO white noise.... (very minor, if any).
This is what your "1/2 throttle" does.....

The more RPM/thrust... the higher the airflow... the more white noise, due to the "duress" that higher airflow has then.
If you have little white noise, "jet" sound.... you have airflow that is too 'clean'. A Habu has a very 'clean' ducting system. The only way to get white noise from that situation is to have a LOT of airflow that "over-drives" its 'cleaness".
You have to choose between performance optimals, and sound optimals.

You also mentioned the take-off 38k RPM, and good sound...... again there is your answer.
More airflow duress... thus more white noise then.
So to get the sound, just as the plane is... fly WOT all the time! LOL
I do understand all of that and a 2800KV motor turning the same fan is equivalent to NEU 3500KV at 1/2 throttle...... so what is the difference? My point is that the NEU 1112/1Y gives me a lot of head room to do the high speed/high thrust that you can't do with a 2800KV motor on 4S.

I heard in the background a newbie ask if that is a real jet on my last takeoff...... think about that, I could hear him ask and he was quite a ways from me with a EDF on takeoff power. No EDF is ever going to sound like a turbine (in loudness) unless we can waste a lot of power making noise.
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Old Sep 11, 2012, 05:50 PM
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rfodor... you said "it sounds like a turbine but very quiet". That is what I commented on.
It is quiet because you don't have enough restrictive/complex airflow.
Nothing to do with what motor..... just what the ariflow is doing.
I have a few CS10's that sound "loud" even from a longish range.... if there is enough white noise, you will hear it from quite a long way. I guess it depends on what you call a 'long' way, because of you fly 500m circuits, displaced away from you, of course notably further away dimishes sound.
And one of those is a Meteor, which is a Habu clone, and it too is loud enough to hear from quite a long way away - and the white noise of it still. (White noise travels well... seeing it has so many freqs in it, they can't all blend away into the ambient sound)
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Old Sep 14, 2012, 01:31 AM
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what would you guys suggest for an alloy shroud for this impeller? looking at getting a 2w30 for the motor, currently have a Turnigy L2855 2100kv but i don't think it will last long.
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Old Sep 14, 2012, 01:41 AM
It should fly at least once
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Have a look here http://www.extremerc.com.au/estore/i...24257337cc3ae5
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Old Sep 14, 2012, 01:55 AM
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i've been overlooking this site for a few days was just curious if there was any other comparable

wish they would tell you which HET motor comes with the combos too.
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Old Sep 14, 2012, 02:13 AM
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try Gary at Efluxrc.com I think he carry's some 70mm skyworld alloy housing and then get a bl32 motor from eflight to go with your cs70/10 rotor....its an awesome setup for 6s!
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Old Sep 14, 2012, 02:42 AM
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Quote:
Originally Posted by xfatdannx View Post
i've been overlooking this site for a few days was just curious if there was any other comparable

wish they would tell you which HET motor comes with the combos too.
Some time ago it did say somewhere there. I believe it's a 2w30 for the 6S and 2w25 for the 4S.

I got a fan only and paired it with my motor and it's excellent!.
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Old Sep 14, 2012, 03:04 AM
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I already have a whole cs unit with a L2855 2100kv but i have not installed or bench tested it. There is an 2w-30 in the classifieds i was considering.
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Old Sep 14, 2012, 03:44 AM
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Quote:
Originally Posted by anlucas View Post
I got a fan only and paired it with my motor and it's excellent!.
I meant, an ExtremeAlloy 70mm 10blade

I also have several standard CS10 fans.
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Old Sep 14, 2012, 10:32 AM
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Vienna, Austria
Joined Apr 2007
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CS70 on the FMS Alpha Jet anyone?

The rather big FMS Alpha Jet 70mm is on sale at HK, so I am wondering if
someone has already tried the CS70 in this airframe, I like the looks and the
price, but not the sound of the stock fan...
cheers
Clemens
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Old Sep 14, 2012, 11:27 AM
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Quote:
Originally Posted by xfatdannx View Post
what would you guys suggest for an alloy shroud for this impeller? looking at getting a 2w30 for the motor, currently have a Turnigy L2855 2100kv but i don't think it will last long.
Well I've been running the 2W-30 in a CS10 for a few months now. Awesome motor, tons of power (you can look back a few pages for a video).

I also just assembled an L2855 2100kv for a HET F20 which I am building. Did a quick run-up so far. Sounds pretty quiet already without any balancing. Got 1200+ watts on 5S, but I am planning to run both 5 and 6S.

Anyone have some long-term experience with this motor?
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Old Sep 14, 2012, 12:42 PM
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Quote:
Originally Posted by nighthawk0077 View Post
Well I've been running the 2W-30 in a CS10 for a few months now. Awesome motor, tons of power (you can look back a few pages for a video).

I also just assembled an L2855 2100kv for a HET F20 which I am building. Did a quick run-up so far. Sounds pretty quiet already without any balancing. Got 1200+ watts on 5S, but I am planning to run both 5 and 6S.

Anyone have some long-term experience with this motor?
To get 1200w+ on 5S means that you are running high timing. On 6S the temps get really high and it won't last very long.

I 've been running one on and off since March. Pretty good on low timing. A touch better than the 2300kv on 5S. Still gets hot so need to manage throttle. In general, it needs to be kept under 65Amps, preferable 60 or less.
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