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Old Nov 04, 2011, 03:27 AM
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This is better: http://www.hobbyking.com/hobbyking/s...s%5F4s%5F.html

1.6kg of thrust
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Old Nov 04, 2011, 03:42 AM
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there must be a mistake there..
you get 1.6kg of thrust ou of 1140watts while on the 5s you get 1482 with 1482watts??? typo mistake obviously
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Old Nov 04, 2011, 03:49 AM
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Originally Posted by pavcon View Post
there must be a mistake there..
you get 1.6kg of thrust ou of 1140watts while on the 5s you get 1482 with 1482watts??? typo mistake obviously
NO TYPO here.

4700kv motor with 4S .. spin faster then a 3700kv on 5S

Not by much BTW

Tchuss

e_lm_70

EDIT ...

Actually the number on the 5S unit are a bit off ... anyhow ...

The 5S @ 3700kv, should spin at around 74k rpm
The 4S @ 4700kv should spin at around 75k rpm

It is possible that the 5S is more efficient, and this will compensate the little less theoretical rpm ... but both unit should provide the same amount of power ... more or less
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Last edited by e_lm_70; Nov 04, 2011 at 03:54 AM.
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Old Nov 04, 2011, 04:51 AM
Extreme CNC Alloy EDF
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Originally Posted by e_lm_70 View Post
I would not believe chinese factory figures, the factory posted a video up of the fan and it was not all that fast in the air, and their thread on the fan died off rather quietly too.
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Old Nov 04, 2011, 04:53 AM
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Originally Posted by DumthumbsFRANKIE View Post
Don....i got your 4000plus setup ...its awsome on 3s ....just got some Gensace 4s 2200 packs and shes pulling 1060watts at 57 amps....why is the watts so high? You say it should only be around 600..... Im puzzled...am i at risk?
Either you are using 5 cell packs or your meter is waaaaay out and should be binned

1060w divided by 57A is 18.5 volts, that 5s under load, and you must have taken the reading a few seconds after banging the throttle open.
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Old Nov 04, 2011, 06:33 AM
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I cant believe that 1100watts can produce so much thrust.
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Old Nov 04, 2011, 08:31 AM
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I cant believe that 1100watts can produce so much thrust.
Why not ?

A 3D propeller plane, can do 2kg of thrust with less power ... with a speed of 100km/h

More or less .. power is equal to thrust x speed ... so .. it need to be known what is the air speed after this EDF ... assuming around 200km/h ... it can make sense 1100watts

Tchuss

e_lm_70
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Old Nov 04, 2011, 09:10 AM
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e lm.. don't compare propellers with edfs.
with my 780 watts 2.2kg F3A foamie I can do unlimited vertical. thatwould barely fly my rclander Panther
in the panther I'm getting 1100watts and I'm talking same cells same battery pack same ESC..

the efficiency of an EDF unit is much less also due to position
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Old Nov 04, 2011, 09:12 AM
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see?? now they corrected the 5cell one
I knew I was right
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Old Nov 04, 2011, 09:36 AM
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Originally Posted by pavcon View Post
see?? now they corrected the 5cell one
I knew I was right
Either the kv is wrong .. or all the number there are just random.

A 5S @ 3700kv ... does not spin faster then 4S @ 4700kv

Power is connected to the RPM

Tchuss

e_lm_70
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Old Nov 04, 2011, 11:26 AM
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Voltage is connected to the RPM.
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Old Nov 04, 2011, 11:34 AM
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Originally Posted by Evan D View Post
Voltage is connected to the RPM.
I was speaking about output power .. this is a direct formula that is based on RPM, are pressure, etc etc (but not on voltage or ampers)

The kv is an extrapolation between rpm and input volts .. but ... the kv is relative accurate without load on the motor, under load, the motor will have less rpm as the kv would suggest.

Anyhow ... either the 3700kv motor with 5S is more efficient then the 4700kv motor with 4S ... or the kv numbers are not very accurate

Tchuss

e_lm_70
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Old Nov 04, 2011, 01:31 PM
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Originally Posted by e_lm_70 View Post
Either the kv is wrong .. or all the number there are just random.

A 5S @ 3700kv ... does not spin faster then 4S @ 4700kv

Power is connected to the RPM

Tchuss

e_lm_70
there is always some loss. especially with high kv motors.
more voltage = more torque too
that was explained tome somehow but when I find it I will repost here
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Old Nov 09, 2011, 07:53 AM
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Hey guys. I would like to cover my Stinger with fiberglass cloth. Can I leave the pre-painted decals on and just cover then add the water base poly acrylic?
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Old Nov 09, 2011, 10:01 AM
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yes you can...

btw can you remember my order..?? still havent' got it... 4 months +
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