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Old Jan 29, 2012, 05:20 AM
RA-TA-MA-HAT-TA
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Melbourne, Australia.
Joined Feb 2010
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Quote:
Originally Posted by MagnusEl View Post
I dont want to start something here, but how do all of you make your measurements? Some numbers dont match...




14,78x69,55=1028W



17,95x90,18=1619W



17,84x99,42=1774W


Its not just 901racer, I have seen unmatching numbers all over the place.

I am trying to understand how the numbers is presented, Volts is the minimum??
Amp maximum peak?
Watts maximum peak?
They'll never match exactly because of the resistance present in the wires and circuitry, but the discrepancy is minuscule, so why harp up about a few watts
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Old Jan 29, 2012, 05:47 AM
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Quote:
Originally Posted by anlucas View Post
Vm : I assume that this is the minimum voltage level reached in the battery during the test. This tells us how "strong" the battery is at providing the current required to spin the motor at the rpms it wants to spin at.

Ap: This is the max amps reached during the test.

Wp: Max watts during the test
THANK YOU anlucas!! Volts is min, Amp is peak and Watts also peak values.

That was what the answer I was looking for!

I dont have a wattmeter so I did not know how the numbers was presented.

I know there has been discussions regarding peak/settle numbers, I think both can bee good to know.


@munce31
Harp up???? I dont even know what that means
I thought this was the place to ask Q:s
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Old Jan 29, 2012, 05:55 AM
Extreme CNC Alloy EDF
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Australia
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Just wanted to post an update as I know a lot of guys waiting on my fans are reading this thread and its easier than sending out dozens of emails .

All backorders are finished!! Finally got through them all and will be shipping most tomorrow. I am out of rotors again so next assembly will start later in February.
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Old Jan 29, 2012, 06:55 AM
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There is noway that cs 480 2800 4mm cyclone power will hold at 97 amps. Have we forgotten that high number blade edf units have been tried before. Anyone ever heard hoaye or flyfly. Sure they sound great but I guarantee they are wasting about 20 amps or so. Try edf hobbies 2950kv motor rotor with a wemo and you will have close to 7lbs with similar amp draw. I suggest you start using lander or skyworld housing because the cheap plastic housing crack and melt with what we are doing.
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Old Jan 29, 2012, 08:29 AM
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Quote:
Originally Posted by anlucas View Post
There's no methodology used so it can be confusing. A bit of a puzzle really. You have to know what you are looking for.

Maybe the way I am presenting my numbers is wrong so anyone please feel free to pick on them.

This is what I have seen people do in these forums and chose to adopt.

I am using a run of the mill watt meter that many have and use.

1. I do a test run at full throttle for about 10 seconds or more and this takes the edge off a fully charged battery then stop. The meter resets.

2. Give full power to the motor and hold for at least 20-30 secs. This simulates a run of the motor in a plane where you apply full power to achieve the max speed or to climb vertically.

3. During the test observe the numbers on the meter that change in realtime. If anything is noteworthy then report it.

4. Stop the motor. The meter now starts to cycle through the statistics and note down the numbers as follows:

Vm : I assume that this is the minimum voltage level reached in the battery during the test. This tells us how "strong" the battery is at providing the current required to spin the motor at the rpms it wants to spin at.

Ap: This is the max amps reached during the test.

Wp: Max watts during the test

Thrust: I think this is the most unreliable number since everybody uses a different stand to measure the pull or push of the fan against a scale.

In the above it would be wrong to use the w=v*a equation since the watt meter does not give the respective volt reading at the time the max watt level was reached.

This is probably what confuses most.
Anlucas -

This is the same methodology I am using, almost exactly. I really don't have time to look at the watt meter much during the pull because I am trying to get an accurate reading from the scale for thrust. I am using the turnigy 130a watt meter in these tests. Also post run I am trying to understand how hot the motor gets and how the windings look. I have got to find my temp gun today. The way you build the test stand will affect your numbers. I have had intake restrictions and exhaust restricts which were posted upthread with pic's but believe I now have that worked out.
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Old Jan 29, 2012, 09:57 AM
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Quote:
Originally Posted by latinajet View Post
There is noway that cs 480 2800 4mm cyclone power will hold at 97 amps. Have we forgotten that high number blade edf units have been tried before. Anyone ever heard hoaye or flyfly. Sure they sound great but I guarantee they are wasting about 20 amps or so. Try edf hobbies 2950kv motor rotor with a wemo and you will have close to 7lbs with similar amp draw. I suggest you start using lander or skyworld housing because the cheap plastic housing crack and melt with what we are doing.
I take anlucas word for it on his testing procedures and the MB1 has done some of these numbers before without burning up. I've done 1700 watts in the stock shroud I think the key there is to do proper cooling procedures on the set ups before powering down.

I've noticed more rotor whine in shrouds that close down the blade gap
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Old Jan 29, 2012, 10:29 AM
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Posting some of the interesting test numbers in one place for comparison. I started compiling this stuff in excel for my own analysis and thought I would post it. I only included the tests that we had all the data for such as thrust numbers. Please note the Tacon watt numbers are settled not peek.

*Note that the L2226-2100kv numbers need to be verified as the tester had Shroud issues that damaged the motor balance he considers these worst case.

I have also included a PDF version for download, it's easier for comparison.

Hoping it will be helpful to folks looking for numbers without having to read the entire thread ... It's getting pretty long.

4S static test numbers:

Turnigy L2855 – 2300KV
4S 4000 40C 
Vm 14.15
Ap 40.77 
Wp 884.2
Thrust(Kg) 1.3
g/w: 1.47

Cyclone CP-480-2800kv
SkyLipo 4S 40C
Vm 14.78
Ap 69.55
Wp 1096.0
Thrust(Kg) 1.53
g/w: 1.39

Turnigy L2855 – 2800KV
4S 4000 40C
Vm 14.36
Ap 63.47
Wp 950.0
Thrust(Kg) 1.6
g/w: 1.67

Tacon 2858-2618kv
4S 30C
Vm 15.00
Ap 60.00
Ws 778.0
Thrust(kg) 1.47
*g/w: 1.89

Turnigy L2855 - 2100kv
4S 3300 25C
Vm: 14.18
Ap: 35.32
Wp: 884.2
Thrust (kg): 1.3
g/w: 1.47

Turnigy XK2850-B-3000kv
SkyLipo 4S 40C
Vm: 14.43
Ap: 69.51
Wp: 1034.5
Thrust(kg): 1.70
g/w: 1.64

Turnigy L2226-3000kv
4S 25C
Vm: 14.3
Ap: 66.38
Wp: 949.8
Thrust(kg): 1.51
g/w: 1.59

5S static test numbers:

Turnigy L2855 – 2300KV
5S 4400 65C 
Vm 18.46
Ap 65.07
Wp 1248.0
Thrust(Kg) 2.0
g/w: 1.60

Cyclone CP-480-2800kv
SkyLipo 5S 40C
Vm 17.95
Ap 90.18
Wp 1675.0
Thrust(Kg) 2.06
g/w: 1.23

Turnigy L2855 – 2800KV
5S 4400 65C
Vm 17.74
Ap 82.84
Wm 1478.6
Thrust(Kg) 2.2
g/w: 1.49

Tacon 2858-2618kv
5S 30c
Vm 18.00
Ap 87.00
Ws 1600.0
Thrust(kg) 2.13
*g/w: 1.33

Turnigy L2855 - 2100kv
5S 4400 65C
Vm: 18.82
Ap: 54.70
Wp: 1067.10
Thrust (kg): 1.8
g/w: 1.69

Turnigy XK2850-B-3000kv
SkyLipo 5S 40C
Vm: 17.65
Ap: 88.70
Wp: 1606.6
Thrust(kg) 2.1
g/w: 1.31

6S static test numbers:

Turnigy L2855 – 2300KV
6S 4500 25C
Vm 20.79
Ap 70.4 
Wp 1511.0
Thrust (Kg) 2.2
g/w: 1.46

Cyclone CP-480-2800kv
6s 2x Turnigy 3s 20-30c 
Vm 17.84
Ap 99.42
Wp 1995.1
Thrust(Kg) 2.6
g/w: 1.30

Turnigy L2855 - 2100kv
6S 4500 25C
Vm: 21.86
Ap: 71.80 
Wp: 1642.7
Thrust (Kg): 2.4
g/w: 1.46

*g/w indicate watts are settled and not peek
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Old Jan 29, 2012, 10:41 AM
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Quote:
Originally Posted by 901racer View Post
I was not able to find my Infrared gun today. Will look again tomorrow or pick up another.

I am going to order a CP 2500 and the 3300 as well. I am sure I will use them. I want comparative thrust and real numbers on those motors as well after seeing this motor.

...
Quote:
Originally Posted by erh7771 View Post
That's pushing some serious get gone, did you happen to take any temps on the bell?

With 20c packs it'll prolly do 6lbs of thrust, wow..I'm going to hit Jack at edfhobbies up.
Ehr and others... Any thoughts on a 4mm vs. 3.17 shaft size .. pro's and con's??

I am ordering the CP 2500 and 3000 but can get them in either size. The CP 2800 I have been testing has a 4mm shaft, I thought the bigger the better but may be giving up performance for longevity ... remember this shaft is really long.
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Old Jan 29, 2012, 10:54 AM
Bypass Ratio = Infinity
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I don't see how shaft size will affect performance.
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Old Jan 29, 2012, 11:04 AM
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Originally Posted by scatsob View Post
I don't see how shaft size will affect performance.
All rotating weight or mass will always affect performance in some manner in any motor. If it's insignificant and just for FAN compatibility that's the sort of guidance I am seeking.
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Old Jan 29, 2012, 11:04 AM
Gorilla Glue Expert
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No 2100?

I guess I need to go back and see just who was running the 2100 L2855.....

At any rate, your numbers are a real help. The Tacon seemed to have the benefit of a better battery, but at 1.89 g/w that is a spectacular run - and on 4s! The 2800 was right behind, at 1.68 g/w, also a fine show.

For my book, the 4mm shafts are just so much stiffer that they're worth it. Keeping the rotor aligned during runtime keeps it off the shroud as well as not deflecting energy input.
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Old Jan 29, 2012, 11:09 AM
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Quote:
Originally Posted by PikeStaff View Post
I guess I need to go back and see just who was running the 2100 L2855.....

At any rate, your numbers are a real help. The Tacon seemed to have the benefit of a better battery, but at 1.89 g/w that is a spectacular run - and on 4s! The 2800 was right behind, at 1.68 g/w, also a fine show.

For my book, the 4mm shafts are just so much stiffer that they're worth it. Keeping the rotor aligned during runtime keeps it off the shroud as well as not deflecting energy input.
I will back track and include them if I can find all the data or point me to the post.
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Old Jan 29, 2012, 11:10 AM
Bypass Ratio = Infinity
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Quote:
Originally Posted by 901racer View Post
All rotating weight or mass will always affect performance in some manner in any motor. If it's insignificant and just for FAN compatibility that's the sort of guidance I am seeking.
It would be insignificant. It is not much more mass and it more or less right on the axis of rotation so the moment will not really change. As the poster above stated, the extra stiffness is invaluable for a smooth running and safe fan.
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Old Jan 29, 2012, 11:13 AM
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Quote:
Originally Posted by PikeStaff View Post
...

For my book, the 4mm shafts are just so much stiffer that they're worth it. Keeping the rotor aligned during runtime keeps it off the shroud as well as not deflecting energy input.
Thanks .. The guidance I was looking for
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Old Jan 29, 2012, 11:32 AM
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'Twasn't you...

Quote:
Originally Posted by 901racer View Post
I will back track and include them if I can find all the data or point me to the post.
AnLucas had some numbers for the 2100 L2855 back on post #1368. No thrust numbers tho.
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