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Old Oct 09, 2012, 07:47 PM
Should've, Would've, Could've
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United States, CA
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Nope 6s is fine and the max i would go on CS12. Im using both 1500kv and a 1600kv setup on 2 different planes on 6s. You may get away with 1700kv, but good throttle management and the right motor would be the key. Either way your fine with the CS12 combo from xflight.
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Old Oct 09, 2012, 08:22 PM
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KV is not a number that sets a parameter on 'is it ok or not'.
But what it does affect/set is what the motor will try to do, or will do (if capable), which then means RPM/load.... thus current.... thus power used.... thus load and heat on the motor and THEN you find out if that motor and KV were a workable total or not. (whether the RPM result is too high or low, or motor stress too high)

eg If you used a 40-120 motor (LOL) of 2000kv on 6S..... it would work too! (how long till the fan exploded???)
Because it would drive the fan to massive RPM, and draw huge current, which the motor would not flinch at because it is so big and capable.

So when you ask "1600kv", it really needs to specify the MOTOR SIZE, to know if it would even cope with it. A weaker motor won't even get to drive the fan to the RPM a 'good'/adequate motor would.
One 'almost adequate' brand motor might run it to 38k RPM, and another 'more than adequate motor' could drive it to 42k RPM.

I hope that adds into your understanding of motors and fan combo reasoning.
What is your (intended) 1600kv motor??..... knowing its make/size will tell if it will be fine at 1600kv.

One more thing... is that if it IS an adequate motor, then by it running the fan at that RPM that it does, currents will be high. probably 100Amps area.... so then you also need batteries with C/IR SUITED to the task.
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Old Oct 09, 2012, 11:20 PM
DONT PANIC! :)
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v8truckin thanks for the response!

peter, i honestly dont know any specs on the motor being supplied with the changesun 12 blade combo. its from xflight....

batteries being used are 4400maH 30c 6s

i have a friend flying a freewing f/a 18 hornet with the changesun 12 blade combo and hes had several flights.

heres the combo

http://www.x-flight.com.hk/index.php...20Expiried!&s=
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Old Oct 09, 2012, 11:56 PM
Should've, Would've, Could've
v8truckin's Avatar
United States, CA
Joined Dec 2010
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I've destroyed 2 - 4000mah 25c gens ace and 1 - 4400mah BlueLipo 30c batteries on the CS12 1500kv & 1600kv setups, but mainly because of my flying style...WOT majority of the time. So I went to 40C & 60C-120C on any plane that I use the CS12 on. Basically if you don't go WOT for prolonged periods of the flight 25C & 30C batteries will hold up fine, again just watch your thumb and manage that throttle. It was hard for me to hold back when you have that thrust/speed at your finger tips, but it took 3 destroyed batteries to calm my tigger finger.
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Old Oct 10, 2012, 12:41 AM
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lol daayum

thanks for the heads up.

hey i see people using a 100a esc. am i okay with that?

also did you have to balance the CS12 1600kv combo?
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Old Oct 10, 2012, 12:56 AM
Should've, Would've, Could've
v8truckin's Avatar
United States, CA
Joined Dec 2010
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You'll be fine with 100a esc on the CS12 xflight combo you should see around 95a static, so inflight you can expect around 75a-85a, depending on battery. Least that's what my telemtey unit was showing my inflight amp draw @. However I do not use the CS12 xflight combo , I run my motor choice (HTG 1600kv & FF 1500kv) and balance the fan myself. So from what I have heard its hit or miss on the xflight combo for balancing.
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Old Oct 10, 2012, 01:31 AM
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That X-Flight combo doesn't really tell you anything of use.
You would HOPE a sold combo would be a 'good' useful one... but you would need to see results from people - threads/posts etc. And even those can often need to be taken with a grain of salt!!

They say "86A"... but with what battery C/IR ???
You can change current draw by 10A or more, across low C to high C.
Like V8's case mentioned... it might not cope with high C batteries.
Or it might not give out great power on low C's.
To me, 86A means it is a weak battery (low C) that was used, OR the motor is weak. I would expect to see 90A area even from average batteries. And 100A, or more, from high C's.
I get 84A from my 1500kv on 30C..... so 1600kv should be that step higher.

By 1600kv in a CS12 on 6S you are entering just into 'high power' territory. That means high loads, that need high currents and good batteries. (it doesn't mean you will use that all the flight - WOT)
So it is a 'high power' combo.... as far as what it will TRY to do. But whether or not it is a capable motor or not.... nothing listed there gives clues on that.
A HET would do it cruising.... but you can bet it is not a HET.
Though I do expect it should be a 'good' system....

It really is in the realms of "Use a good battery" (45C upwards.... you find out accurately what is best when you test it!)
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Old Oct 10, 2012, 02:11 AM
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Quote:
Originally Posted by v8truckin View Post
I've destroyed 2 - 4000mah 25c gens ace and 1 - 4400mah BlueLipo 30c batteries on the CS12 1500kv & 1600kv setups, but mainly because of my flying style...WOT majority of the time. So I went to 40C & 60C-120C on any plane that I use the CS12 on. Basically if you don't go WOT for prolonged periods of the flight 25C & 30C batteries will hold up fine, again just watch your thumb and manage that throttle. It was hard for me to hold back when you have that thrust/speed at your finger tips, but it took 3 destroyed batteries to calm my tigger finger.
When u say destroyed - how do I know when it is bad for flying ? I mean my TP 5000 is 20c -40c and it comes down hot and swollowed a little ... is that bad ? Im about to get new batteries , should i get at least 40c ? Cause that what i was thinking
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Old Oct 10, 2012, 03:40 AM
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Quote:
Originally Posted by out of stock View Post
question. is 1600kv too much for 6s? someone previously posted 1600kv being too much for 6s and that it would burn up the motor. true or false?

i have 2 planes flyfly mirage and L-39.

the mirage im going with a 6s setup from extremeRC. the 39 will be getting the low budget changesun 12 blade 1600kv combo from xflight. im confused about this 6s 1600kv stuff.
I run mine with a HET Typhoon 600-37-2 (No load KV : 1700) on 6S
done over 40 flights, no problems so far
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Old Oct 10, 2012, 04:05 AM
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Quote:
Originally Posted by kakofonixx View Post
I run mine with a HET Typhoon 600-37-2 (No load KV : 1700) on 6S
done over 40 flights, no problems so far
Do you have any idea how many amps your pulling on the motor?
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Old Oct 10, 2012, 04:07 AM
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Quote:
Originally Posted by kakofonixx View Post
hehe!
I have the same motor + edf setup and installed in the same airframe!
I measured it around 70A and 1500W on Flightmax 6s 4000 Mah, 20 C
Haven't fly it yet with the new fan due to bad weather conditions...
I will post some info when I'll do
never mind found it.

Thanks
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Old Oct 10, 2012, 04:31 AM
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Canada, ON, Burlington
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Those interested in the X-Flight combo
I have been running it many flights (+30) in my Starmax F/A-18. It was very difficult to get dynamically balanced as there were issues with the adapter fit, and the motor can/bell was slightly bent and out of balance. All posted earlier in this thread.
Once set up It has been trouble free. Great 6S fan that will settle between 85-95A depending on battery condition/C rating. I believe the 1600kv is wrong and is actually much closer to 1500kv.
Cheers
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Old Oct 10, 2012, 04:55 AM
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Sounds like what the specs suggested it would run at....

Koren, it is not as simple as someone saying "Yeah get higher C as they can cope with more".
When you use higher C (lower IR) they feed more volts to the motor. Thus it runs faster... draws more current (than with the lower C battery).... which adds up to more power.... and the 'new' battery is now under more duress as it is supplying more current, which it was designed to do, but the end result could be a battery that runs just as hot as the original lower C - IF you use that higher power level it can provide.
As long as you use the same power level as with the prior lower C battery THEN it will be an easier load for this new higher C battery, and thus an easier life for it.
You also might find you move the motor into higher load territory that it can't truly handle, or survive with. (or even the fans RPM limits).

It is easy enough to say "I will use lower throttle and thus run it at lower power - much like I had to run the prior battery at max throttle to achieve an output power of amount X", but in reality it is harder to control throttle - and yourself - to accurate limits/positions.
If the lower C battery was power level X at 100%, where is the same power level on the higher C setup? 80%? 70%? How are you going to get the stick to that exact position? How are you going to control yourself even?
Basically you won't..... you will tend to exceed what power level you had before, half because you don't even truly know where that throttle (power) point is, and half because huiman nature will make you USE the full power at least Y amount of the time. Even partly due to the fact it is EASIER to hit full stick than finding 90% or 95% etc.

So you really need to TEST any combo - and that means with specific battery - to see what that total combo will do, and cope with. And to locate and record the power points you might want to know. (eg 1500w area, 1600w area)
It is not quite as simple as throwing some more C at it. Not if you want to end up with the most economical and appropriate total of items for that plane, that will also last.
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Old Oct 10, 2012, 06:14 AM
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That is the most detailed answer i ever got !!! Thank you
Ok , so if im after let say 1800w , with a motor of 1500kv , and need to buy new batteries - what C rate should I get ? I was told along the way that the higher C rate would be easy on the battery , and it will function better under load , specially when we are talking EDF .... isn't that true ?
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Old Oct 10, 2012, 06:39 AM
Life begins at transition
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Absolutely.

Yes, a higher C battery should have a lower IR. Assuming that's the case, it will hold a higher voltage, and therefore spin the fan faster.
That in turn means it will draw more current.

But: The increase in current will never be greater than the increase in discharge capacity.
A 40C does not hold 1.4 times the voltage of a 20C pack (as would be required to double the power draw).

So in short - a higher rated pack will have an easier time dealing with the load, and will come down cooler (lower IR is still assumed...) The major disadvantage is weight. A higher C battery tends to be a bit heavier.

I look at IRs rather than C rating, mostly as there is a very rough correlation, but C is driven by the marketing department!
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