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120 mm shulman fans

Old 03-29-2011, 03:57 PM
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never-enuff
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Default 120 mm shulman fans

if anybody out there can help, I've got two shulman 120 fury fans with castle creations 160 HV speed controllers on 12s 45c 5000 ma. Battery packs that I bought from an individual here on RCU. They are only putting out 2200 watts and 62 amps at full throttle or 100%. I've tried the same batts and speed controllers on another 120 fan and I'm getting 3600 watts and 85 amps, which is where the two fans should be. I've tried all 3 timing settings with very little change. Battery voltage is where it needs to be. Also I have downloaded the specs off of the speed controllers, and is the same as my meter. The guy I bought them from will not answer my Emails or phone calls. And I will let everybody out there know who he is before this is over. He said the plane flew perfect. ( HE LIED!!!!!!!! ) Don't know what else to do. Thanx guys. Scott
Old 03-29-2011, 04:06 PM
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Freddy!
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Default RE: 120 mm shulman fans

Times are tough,wish i could help you out,maybe KVs on motor or speed control. Dave
Old 03-29-2011, 04:51 PM
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Default RE: 120 mm shulman fans

Thanx they are 830kv
Old 03-29-2011, 05:15 PM
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Larry Dudeck
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Default RE: 120 mm shulman fans

"...I've tried the same batts and speed controllers on another 120 fan and I'm getting 3600 watts and 85 amps, which is where the two fans should be...". Which leaves either the fan itself or the motor.

Is there any possibility of installing the impellor backwards?

Is there any possiblity of the motor running in the wrong direction?

Is there any possibility of the wrong impeller? What kind of clearance is there between the impellor and the shroud?

If the impellor is correct then the problem must lie in the motor.

Good luck in finding the solution, sounds like expensive equipment to me.
Old 03-29-2011, 05:41 PM
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Default RE: 120 mm shulman fans

Are they wired together or separate?
Bob
Old 03-29-2011, 07:51 PM
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Default RE: 120 mm shulman fans



Shulman fans are just rebadged Lander fans, the specs should match up with whatever lander quotes.

With that said you dont say if you are testing both fans on the single pair of 5000mah 6s packs or not. Because if you are running both fans at once the batteries are being hammered and I am surprised you are not hitting LVC a few seconds after powering up.

Look at your figures:
2200w for 62A...Thats 35.48 volts!! IE under 3v per cell if its a 12 cell setup! Thats terminal for the batteries, they would get hot pretty quick running like this.
Do you mean the pair of fans is pulling 4400w at 124A?

3600w at 85A = 42.35v = 3.53v per cell, thats a more reasonable load and what one would expect from a single fan running on reasonable quality 12s packs.
The batteries are by no means premium quality cells though, when testing my 127mm fan at 100A I am holding 44v under load using 5000mah 35c cells.

Try running a single fan on the pair of batteries you have and get back to us.

Old 03-30-2011, 04:27 AM
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Default RE: 120 mm shulman fans

Separate
Old 03-30-2011, 04:28 AM
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Default RE: 120 mm shulman fans

That is one fan on 12 s
Old 03-30-2011, 05:11 PM
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Default RE: 120 mm shulman fans

If its one fan on 12s then there is something seriously wrong with the whole scenario, could be screws too long when assembled touching the windings and causing a weak short but that would show huge amps, so its still pointing towards the batt, was it charged??

The issue with your figures is the voltage, you need to test it again and post up the exact figures, pack voltage under load, watts and amps, and make sure its freshly charged. Everything says the pack is stuffed, but if you reckon its giving 3600w on another 120mm fan at 85 odd amps then the pack is operating ok, so right now no one can give you a difinitive answer.
Old 03-30-2011, 07:29 PM
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Default RE: 120 mm shulman fans

I know this is going to sound like a stupicd idea, but it's worth checking.  Are you running 12S packs or are you running 2 6S packs wired in series?  If you're running two 6S packs wired in series, you may have inadvertently a set-up the batteries with a parallel wiring harness for the packs and not a series harness.  I'm saying this because i did this once in one of my pattern ships, accidentally installed a parallel harness instead of a series harness.  I was able to take-off and barely had enough power circle around and  - greased it on by the way. 

Another thing to check is the travel limits on your throttle set-up.  Make sure you haven't limited the esc with end points or dual rates.

If these suggestions don't work, time to resort to swaptronics.


Rob
Old 03-30-2011, 11:50 PM
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Default RE: 120 mm shulman fans

His voltage says no way it could be parallel, that would be 25v and his 2200 watts divided by 62A gives you 35.48v. More like a very discharged 12s setup.
Old 03-31-2011, 02:56 AM
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Default RE: 120 mm shulman fans

Throw 2 cents in:

The motors are the low KV, move up a notch...batts are not 25 or better. Look to replace the batteries with 40-50C, first...check it out, if still low, move up the kv of the motors. 12 cells is alot to carry. 15 cell? 4.2 x 15 is 63 volts...too much so three 5 cell packsi s no good. 12 cells is cool...a lipo under 100% should still be 3.8 fully charged... if your total pack is 45 volts at 100% then you are using good batteries.
Old 04-07-2011, 01:39 AM
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Default RE: 120 mm shulman fans

So what happened with this?? Did you retest and confirm your numbers?
Old 04-07-2011, 02:58 AM
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Default RE: 120 mm shulman fans

I have retested everything time after time with the same outcome. I'm working with Lander now. I've sent the data off of the Speedcontrollers on all three timing settings. They have not figured it out yet either.

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