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Old Dec 11, 2011, 08:44 PM
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United States, GA, Alpharetta
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Originally Posted by bamaguy View Post
IMHO:

The higher KV motor was working it's butt off trying to get up to it's design RPM/Volt...drew too many amps and overheated. Even though the pitch of those ten blades is less than that of the typical 5 or 6 blade rotor, any motor must work harder to spin it up. Your motor wanted to spin it at about 54K, or so. Too much load on it.

Try that 2300KV it will be much improved. Rotor is happy around 44000 RPM. That's where you will obtain some decent thrust. (It will be a little lower than the stock rotor....and draw about 10 more amps....but it will sound real nice, IF the rotor/motor are balanced pretty good.)

Your LiPo should be at least a 5S3300-30C.......more mAh size if you have one...and if it would fit!
It takes over 2000 watts to spin that fan at 44,000 RPM..... I know because I did it with a ARC 28-58-1 on 5S and it cost me $45.00 - the cost of a replacement motor. The Castle Ice recorded 2600 watts at 45000 RPM and that was only for 10 seconds. On 4S, with the replacement ARC, it spins at 39000 RPM at around 1600 watts.
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Old Dec 11, 2011, 08:52 PM
Don't Move I've Dropped My Nut
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United States, AL, Huntsville
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Quote:
Originally Posted by rfodor View Post
It takes over 2000 watts to spin that fan at 44,000 RPM..... I know because I did it with a ARC 28-58-1 on 5S and it cost me $45.00 - the cost of a replacement motor. The Castle Ice recorded 2600 watts at 45000 RPM and that was only for 10 seconds. On 4S, with the replacement ARC, it spins at 39000 RPM at around 1600 watts.
On 4S, it probably read around 100 amps?? And on 5S, in excess of 120 amps??
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Old Dec 11, 2011, 09:51 PM
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Originally Posted by Michael Paxton View Post
It's actually two carbon spar rods going out to about 2" from each wing tip. The straw is to cover and give an airfoil in front of the fan.
Thanks for that....I thought it might have been to separate or control the airflow into the fan.

I have a Kamdax M2000 which came with this plastic card. I had no idea what it was for then finally read a few threads which pointed out what it did and where it went. Because the M200 has a twin intake setup it was a fence to assist with the air flow going into the fan.

Your F-16 must be pretty hard core to need carbon spars from wingtip to wingtip. Very nice.....
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Last edited by Burdo; Dec 11, 2011 at 10:01 PM. Reason: Fix spelling errors
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Old Dec 11, 2011, 09:54 PM
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Originally Posted by bamaguy View Post
On 4S, it probably read around 100 amps?? And on 5S, in excess of 120 amps??
On 5S with the arc it was pulling 145 amps, 2600 watts...... for 10 seconds. On 4S it is pulling 109 amps 1550 watts turning 38850 RPM.

Both are with an inlet lip in a SAPAC shroud.
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Old Dec 11, 2011, 09:58 PM
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Originally Posted by jcdfrd View Post
well we had the ammo 2300kv motor and fan all ready to drop in but we figured with even lower kv on the same 5s pack performance would go down even further so we didn't try it, maybe we should have.
This fan is definitely worth persevering with to find that right combination between speed and sound....

I would try the 2300kv on 5S and I think you'll be much happier. I ran a 2800kv on 4S which hit that sweet spot for me....I have sacrificed speed for sound, but was the trade off I wanted

We also have to remember that this is not an extensively developed EDF which will produce a great amount of thrust like a Stumax (for example).

Trying to spin this fan too fast and some serious precautions need to be taken.

Not sure whether I read it in his thread or the CS 90mm thread, but someone has already had a blade break off at high rpm. Luckily no-one was injured...
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Old Dec 11, 2011, 10:06 PM
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Quote:
Originally Posted by Burdo View Post
This fan is definitely worth persevering with to find that right combination between speed and sound....

I would try the 2300kv on 5S and I think you'll be much happier. I ran a 2800kv on 4S which hit that sweet spot for me....I have sacrificed speed for sound, but was the trade off I wanted

We also have to remember that this is not an extensively developed EDF which will produce a great amount of thrust like a Stumax (for example).

Trying to spin this fan too fast and some serious precautions need to be taken.

Not sure whether I read it in his thread or the CS 90mm thread, but someone has already had a blade break off at high rpm. Luckily no-one was injured...
Manufacturer states that Maximum Watts is 1800/max RPM is 52,000 Probably a good idea not to go near 50K!


http://www.windrider.com.hk/products...161456spec.jpg
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Old Dec 11, 2011, 10:25 PM
Lee Liddle
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Carrollton, Tx
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Quote:
Originally Posted by bamaguy View Post
Manufacturer states that Maximum Watts is 1800/max RPM is 52,000 Probably a good idea not to go near 50K!


http://www.windrider.com.hk/products...161456spec.jpg
Well those are kind of screwy specs because 1800w would be waaaaay less than 52,000 rpms on this rotor. So the 1800w is worthless as a number, but then again, so is 52k rpm.

Guess we`ll just have to find the specs ourselves as usual.
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Old Dec 12, 2011, 07:04 AM
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Fairborn, OH
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I have a Velocity 2900KV motor I was assuming would work well with 5S but after reading here, it sounds too high. On the other hand, is it too low KV for 4S? If the ARC 28-58-1 was drawing 109A, maybe this set-up would be sub-100A with 4S. Thoughts?
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Old Dec 12, 2011, 07:26 AM
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Originally Posted by alexandermh View Post
I have a Velocity 2900KV motor I was assuming would work well with 5S but after reading here, it sounds too high. On the other hand, is it too low KV for 4S? If the ARC 28-58-1 was drawing 109A, maybe this set-up would be sub-100A with 4S. Thoughts?
It should work. See post 649 of this thread. Start off with low timing and go from there.
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Old Dec 12, 2011, 08:15 AM
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Thanks. Looked at Post 649. The Turnigy L2855 2800KV motor referenced in that post is an outrunner, rated only for 4S and 630W. The Velocity 2900KV motor is rated up to 24v, and 1900 watts burst on 6s lipo. So it sounds like the Velocity motor would have some "headroom" at 5S, and maybe give me closer to 1000W, at below 100A (just wagging here).
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Old Dec 12, 2011, 09:05 AM
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Originally Posted by alexandermh View Post
Thanks. Looked at Post 649. The Turnigy L2855 2800KV motor referenced in that post is an outrunner, rated only for 4S and 630W. The Velocity 2900KV motor is rated up to 24v, and 1900 watts burst on 6s lipo. So it sounds like the Velocity motor would have some "headroom" at 5S, and maybe give me closer to 1000W, at below 100A (just wagging here).
The ARC is 3180 KV, I think a 2900 - 3000 kv motor on 4S (with a battery that can supply all the power the motor wants) would be about right you should get about 35000 RPM at around 80 -90 amps. Around 1300 watts. Don't even think about 5S with the 2900 kv motor in this fan. In a SAPAC, WEMO, HET fan 5S would be fine but not the CS10.
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Old Dec 12, 2011, 09:31 AM
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EDF Motors: Application Versus Specification

Gentlemen:

I am impressed with the expertise and significant contributions of the RC Group in the advancement of the hobby.

Just one concern - I have noted many EDF Motor applications that go beyond manufacturers' specifications. Example: Turnigy XK2860-B-2200KV rated for 45A Max, 11.1V Max, 500W Max set up (application) on a ChangeSun 70mm 10 blades fan on 6S 3000 mAh at 73A. Apparently, this is a successful system (for how long?).

Yet, when I operated a combo/factory balanced ChangeSun 90/5 blades at 6s 5000 mAh, the motor smoked. Same battery/ESC (Hobbywing 100A Opto) system worked very well on WM Midi/ARC 3665-1 (balanced by Extreme RC). Is this a case of "You get what you pay for" or did I happen to get a lemon from a good bunch?

I am for spending less, but I believe successful operation is paramount.

One other question: How do you remove the motor from a CS90 fan. I tried debonder, so far unsuccessfully. I am considering applying heat but it may distort the fan. Any tips?
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Old Dec 12, 2011, 09:43 AM
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United States, TX, Grand Prairie
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Originally Posted by delperena View Post
...I have noted many EDF Motor applications that go beyond manufacturers' specifications....
Many times manufacturing specs aren't max and with EDF you don't fly max 100% of the time.

Quote:
...Yet, when I operated a combo/factory balanced ChangeSun 90/5 blades at 6s 5000 mAh, the motor smoked. Same battery/ESC (Hobbywing 100A Opto) system worked very well on WM Midi/ARC 3665-1 (balanced by Extreme RC). Is this a case of "You get what you pay for" or did I happen to get a lemon from a good bunch?..
What were the batteries C rating, if batteries C rating is high for instance and it holds to 24volts then that's beyond what the video examples I've seen will do. Many have flown with the CS 90mm combo so it's possible it's a dud. From what I've learned so far; Outrunner windings run slightly cooler than inrunners and their magnets don't demag as much cause of heat. Innrunners can be made to a larger size but also can run hotter. A longer can motor is going to give more of it's energy to motion than heat and that's for inrunner and outrunners. The more expensive in and out runner motors usually have less internal resistance (less heat) and better magnets ...giving more power.
You can go beyond specs if you can keep things cool, that's why my testing always includes a heat test after 45 seconds of WOT to see if the motor is holding heat.

Quote:
....I am for spending less, but I believe successful operation is paramount...
I am too for spending less, lately I've been trying out the TACON motors since HK doesn't sell too many 74mm motors that don't hold heat. So far so good, 8lbs of thrust\50 amps\12s on an 810kv TACON motor in a Starmax (Wemo MIDI knock off) fan.

Quote:
...One other question: How do you remove the motor from a CS90 fan. I tried debonder, so far unsuccessfully. I am considering applying heat but it may distort the fan. Any tips?
If you were able to get the 5 blade rotor off then the motor shaft will remove with the motor. Just unscrew the motor from the shroud.

HK sells some medium can 1800kv motors that will replace the one burnt out and should run cool.
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Old Dec 12, 2011, 10:22 AM
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Motor Removal

I was not very clear in my motor removal problem from a CS90mm EDF combo. What I feel to be a logical start is to unscrew the spinner - does not budge even after applying a debonder.

I am thinking of a tool that will give me a good leverage. The rods I have used bent like spaghetti. The tool will be a "U" with an opening slightly larger than the spinner diameter. The "U" ....... now, I see many options.

I am sure, you guys have done this with better results.
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Old Dec 12, 2011, 10:34 AM
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They use thread lock on the spinner/nut. If you have a soldering iron on 100W or more, just use it a short time on the spinner and you should be able to unscrew it. I did ruin a perfectly good screwdriver on my first try, (without heat..) used a CDrom rail shaft grinded to perfect fit on second try and that worked.
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