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Dec 22, 2010, 10:47 PM
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Flip Flop's Avatar
New Product

Change Sun 120mm and new 10 blade 70mm fans


Does anybody have any info or #'s on these? I just ordered two of the 70mm fans from x-flight to try out.http://www.x-flight.com.hk/index.php?p=6&id=121&lang=enhttp://www.x-flight.com.hk/index.php...&more=&lang=en
Last edited by Flip Flop; Jun 27, 2011 at 07:33 PM.
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Dec 23, 2010, 10:54 AM
Gilbert, AZ
chalmrast's Avatar
Hmmm.. 4 blades on that 120mm unit. I'd like to see some testing!!
Dec 23, 2010, 11:00 AM
High Dynamic Thrust
stoneenforcer's Avatar
like to see some real watts put though that!! a 4 blade will show its true output on the high end
Dec 23, 2010, 09:29 PM
Registered User
LuvEvolution7's Avatar
are these the same ones they sell at Hobby King?
Dec 23, 2010, 09:33 PM
Suspended Account
.

they look alike but do they have the same quality?
not very sure about that.
Dec 23, 2010, 09:39 PM
Registered User
Flip Flop's Avatar
From this picture it looks like the rotor might even be balanced, not bad for $17.00.
Jan 08, 2011, 08:12 PM
Registered User
marell01's Avatar
Ive got mine, 70mm a couple days ago, Will do some testing...
Jan 09, 2011, 08:55 AM
Registered User
jhaywood's Avatar
Quote:
Originally Posted by ultraflite
.

they look alike but do they have the same quality?
not very sure about that.
I would hope they are higher quality. The 90mm that I got from Hobby King is junk. There are holes in the edges of the blade and this of course causes severe balance issues.
Jan 09, 2011, 10:55 AM
AKA Terry Till
ex-racr's Avatar
Guys,
I ordered a couple and got them a few days ago. I have already run one of them up and here's what I can say:
The Change Sun 70mm fan is made from a fiberglass reinforced polyphenaline sulfide plastic, just like the E-Flite Delta V 69. The rotor is very rigid. The housing and bell mouth adapter are made of the same material. Also, the 4 bladed rotor has a significant amount of twist in the blades. Compared to an Eflite 69mm rotor and RC Lander rotor, which I had laying around, the angle of attack at the tip of the Change Sun rotor is less, so it won't draw as many amps as a mini-fan, RC Lander fan, E-flite, etc.
The fan units arrived without defects and the moldings were very well done. The motor tube is about 28.5mm ID. 29mm motors will not fit without sanding the inside. The motor tube is some what thin so sticking a Neu in there won't leave much in the way of wall thickness. However the housing has the same OD as a HET 6904. It's a drop-in replacement for a HET. There were no ridges between mold parts. Also the rotor is held on by a collet design. The fan unit comes with a 4mm and a 3mm shaft adapter. Yes, 3mm. They need to get that fixed to 3.17mm ASAP. Also, the rotor does come "balanced", but initial run ups produced some vibration. I elected to refine the balance. It took quite a while, but I now have a unit with ZERO vibration. Also the collet assembly was slipping relative to the rotor. A little washer of sandpaper fixed that.
I ran the motor up using 6S 2200 partially charged to 3.8 volts per cell (was checking the balance). The motor was a Mega 16/25/2E (kv=2300) Full throttle produced 31 amps on a partially charged pack using the supplied bellmouth. As I was holding the unit in my hand, I was more concerned about not letting go of it. Also, FWIW, before I used the sandpaper washer, the rotor was "chattering" from slipping, which loosened the nut and sent the rotor flying. Luckily I was in my workshop and nothing got damaged. Not even the rotor. So, I was more concerned with everything staying together than recording watts. I'll do that later and post in my 6S 2200 thread.

Terry
Last edited by ex-racr; Jan 09, 2011 at 01:03 PM.
Jan 10, 2011, 01:29 PM
AKA Terry Till
ex-racr's Avatar
Ran up the fan. Results are here:
https://www.rcgroups.com/forums/show...4#post17062352
The rotor has less load than a mini-fan, RC Lander, HET, etc. When selecting motors either bump up the kv a little or expect slightly less watts. It suits my needs just fine and will be putting it in a HET F-86

Terry
Jan 22, 2011, 03:02 PM
Electronics and RC
MegaTesla's Avatar
Hmmm... A 4 blade rotor in a 4 vane stator. That might make it slightly less efficient.
Jan 22, 2011, 03:52 PM
AKA Terry Till
ex-racr's Avatar
Quote:
Originally Posted by MegaTesla
Hmmm... A 4 blade rotor in a 4 vane stator. That might make it slightly less efficient.
Actually, it's not the number of stators vs. the number of rotor blades that relate to efficiency. It's whether the stators recover all the swirl imparted from the rotor.
Having a matching number of stators and rotor blades does relate to the sound (harmonics) the fan makes. Perhaps tomorrow I can take a little video of the fan installed in my HET F-86 and you can hear it. Need to make a thrust tube first.

Terry
Feb 04, 2011, 03:19 PM
Registered User
Flip Flop's Avatar
I just ordered one of these combos for a falcon 120, not bad for $220. 7kg of thrust at 118amps without a lip is worth a shot, hopefully it will fit into one of Rodgers nacelle's.http://www.x-flight.com.hk/index.php...4&new=&lang=en
Feb 04, 2011, 09:17 PM
Registered User
Not bad at all
Feb 11, 2011, 08:38 AM
Why kamikaze pilot wear helmet
mikes68charger's Avatar
Has anyone eles tired the 70mm fan yet? What ya think?


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