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Old Jul 05, 2011, 06:47 PM
Extreme CNC Alloy EDF
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Australia
Joined Mar 2006
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When I first tested my Custom machined 64mm "wemo" fan on 4s I used an old pack that sagged out to 13.6+ volts, pulled 62A and produced 1400g thrust sustained on the test stand. In the air in an ARC-Vector Jet and a new 2600mah 40c pack this equated to 125mph+, the wemo rotor is still one of the best performing and most efficient.

What we need to see is EPF fan in a similar model in the air, my reason is because landers 70mm rotor produces similar thrust to the wemo 70mm rotor on the bench but in the air its noticeably slower.
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Old Jul 05, 2011, 09:31 PM
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Originally Posted by JimDrew View Post
This technology is not knew or innovative, and proof of the "patent" has been basically refused to be given. That is the only negative I see.
We already got the USA Patent.
Germany Patent, too.
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Old Jul 05, 2011, 10:03 PM
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Originally Posted by ApexAero View Post
Funny thing happened this weekend, I was given an old 64mm Lander fan, I installed a 1W30 with a trimmed down e-flight impeller, got 2100 watts at 146amps at 56k rpm. All made with stuff laying around. Nothing is better than old junk in my oppinion! New junk is just that.....
I am series to say that you must be a good engineer.
Could you share how to make it?
In case of someone wanna more thrust.
They can do it by themself.
Would you have the thrust data?
I will give our engineer this target to try to catch it.

have a good day.
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Old Jul 05, 2011, 11:39 PM
EDF rules... :)
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Joined Nov 1999
13,648 Posts
Obstructions in either side will create losses.
Since an edf is a closed system, the air volume entering the fan will be the same volume that exits out of the outlet, the fan only adds momentum to the flow. To change velocity you need to change the area of the outlet in comparison to the inlet or velocity of the outlet will be the same as the velocity of the inlet.
Fans are volumetric controlled by Fan Swept Area which is defined as the inner area of the shroud less the area of the rotor hub, this area meters the air volume that passes the rotor every rpm. This air volume multiplied by the velocity added to the flow produces thrust, more rpm more thrust.
The end result is an obstruction at the inlet will produce a similar loss as the same obstruction in the outlet the difference is the inlet air turbulence will affect the flow thru the rotor affecting the power used to move the air (losses). An obstruction in the outlet will add drag to the airflow slowing it a little causing the flow to need more power(losses).
one last item of interest is this fan has obstructions on inlet and outlet and a motor fairiing cone there is more surface area drag in this fan than in conventional tractor/pusher fans even if the obstructions are aerodynamic shapes, think how much drag is on a monoplane compared to biplanes.

Eric B.
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Old Jul 06, 2011, 12:01 AM
jbc
WHO's your DADDY!!!
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Australia, SA, Adelaide
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Originally Posted by SMorrisRC View Post
Why is everyone being so negative? I have the 'old' units and I think, especially for the price, that they are rather good and well made / designed. I can't wait for my new mercury fans to arrive, as they look even better. I like the looks, the sound, the build, and the design. Just need to like the performance when they arrive.
I agree, 7 pages in and still the Patent thing I don't hang around on the EDF threads so much...lol seems more about politics than products most of the time compared to say the warbird/prop threads (just my opinion)
I saw a few youtube vids last night on the old units, they looked quite nice and sounded VERY nice will await your reports on your new mercury units with baited breath Mr SMorrisRC

I'm kinda with Mark on the Wemo thing though, dollar for dollar and efficiency the Wemo's are hard to beat. Not to mention the weight saving (plastic for Wemo) Vs Metal (in this case Mercury).

I'm not knocking these fans at all, maybe if metal fans are the next evolution in EDF's hopefully we can see some serious power coming out of em . Then also one must think of the application, a 70mm jet for example only has so big a battery bay, and if it's foam, can only handle so much wing loading etc etc...it's great if these new generation of fans can produce all this beautiful power but if the platform it's designed to go in can't, then it's wasted IMO. For example a Minifan with the right motor/batts is capable of producing enough power for most foamie models and batt technology that's out atm. I guess if we start going composite then the game changes again and maybe that's where these newer style fans may shine... I dunno just throwing it out there

Oh and seeing as I didn't get an answer before, EPF HOBBY what is the weight of the Mercury fan unit?

Thanks
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Old Jul 06, 2011, 12:07 AM
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St.Catharines, Ontario
Joined Jan 2009
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well, it's like Air says, to get more power, you've got to put more power in. more RPM gives more thrust, efflux speed and a faster plane. the new generation of alloy EDF's are all about this. look at Mach's alloy fan(s).............6.5-7 lbs of thrust from a 70mm fan and this is only the beginning. there's plenty more to come once people start experimenting with power and setup. these alloy fans can be spun faster than any plastic, or combination of plastic and other materials, with little fear of distortion or breakage. I hope these guys can do the same thing here, because this only makes the hobby better for all of us. perhaps EPF should consider making the rotors out of alloy also, so that higher numbers can be produced. this only makes sense, since the weight of this is potentially higher than your typical fan setup.
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Old Jul 06, 2011, 12:13 AM
jbc
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Quote:
Originally Posted by AirX View Post
Obstructions in either side will create losses.
Since an edf is a closed system, the air volume entering the fan will be the same volume that exits out of the outlet, the fan only adds momentum to the flow. To change velocity you need to change the area of the outlet in comparison to the inlet or velocity of the outlet will be the same as the velocity of the inlet.
Fans are volumetric controlled by Fan Swept Area which is defined as the inner area of the shroud less the area of the rotor hub, this area meters the air volume that passes the rotor every rpm. This air volume multiplied by the velocity added to the flow produces thrust, more rpm more thrust.
The end result is an obstruction at the inlet will produce a similar loss as the same obstruction in the outlet the difference is the inlet air turbulence will affect the flow thru the rotor affecting the power used to move the air (losses). An obstruction in the outlet will add drag to the airflow slowing it a little causing the flow to need more power(losses).
one last item of interest is this fan has obstructions on inlet and outlet and a motor fairiing cone there is more surface area drag in this fan than in conventional tractor/pusher fans even if the obstructions are aerodynamic shapes, think how much drag is on a monoplane compared to biplanes.

Eric B.
Great info Eric but curious, are you saying tailcones that we sometimes see on the back of fans/motors cause drag?

@LuvEvolution looking at EPF's video I'm pretty sure the rotor looked alloy.
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Old Jul 06, 2011, 12:24 AM
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I dunno, didn't look particularly shiny to me.

one way to find out...............

hey EPF, is the rotor alloy or a plastic combination of some kind?

you're right though, it does look like it's metallic.
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Old Jul 06, 2011, 12:52 AM
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Quote:
Originally Posted by LuvEvolution7 View Post
I dunno, didn't look particularly shiny to me.

one way to find out...............

hey EPF, is the rotor alloy or a plastic combination of some kind?

you're right though, it does look like it's metallic.
The Rotor is high impact Alloy.
All of parts of Mercury 64A were made by CNC cutting.
No more plastic.
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Old Jul 06, 2011, 12:55 AM
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good stuff. should be able to push a lot more power through this fan than what's been tried already. I'm seeing 6S in this fan's future.
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Old Jul 06, 2011, 01:02 AM
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Quote:
Originally Posted by jbc View Post
I agree, 7 pages in and still the Patent thing I don't hang around on the EDF threads so much...lol seems more about politics than products most of the time compared to say the warbird/prop threads (just my opinion)
I saw a few youtube vids last night on the old units, they looked quite nice and sounded VERY nice will await your reports on your new mercury units with baited breath Mr SMorrisRC

I'm kinda with Mark on the Wemo thing though, dollar for dollar and efficiency the Wemo's are hard to beat. Not to mention the weight saving (plastic for Wemo) Vs Metal (in this case Mercury).

I'm not knocking these fans at all, maybe if metal fans are the next evolution in EDF's hopefully we can see some serious power coming out of em . Then also one must think of the application, a 70mm jet for example only has so big a battery bay, and if it's foam, can only handle so much wing loading etc etc...it's great if these new generation of fans can produce all this beautiful power but if the platform it's designed to go in can't, then it's wasted IMO. For example a Minifan with the right motor/batts is capable of producing enough power for most foamie models and batt technology that's out atm. I guess if we start going composite then the game changes again and maybe that's where these newer style fans may shine... I dunno just throwing it out there

Oh and seeing as I didn't get an answer before, EPF HOBBY what is the weight of the Mercury fan unit?

Thanks
Hello Jbc,
total Weight is 150~160g(approx.)motor included.
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Old Jul 06, 2011, 01:23 AM
Xtreme Power Systems
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Joined Jun 2005
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Quote:
Originally Posted by EPF HOBBY View Post
We already got the USA Patent.
Germany Patent, too.
That's great... provide the number - as you are required under U.S. law. Otherwise, go away with your patent claims. They are useless without a patent number.
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Old Jul 06, 2011, 05:29 AM
WiggleWiggleWiggle
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South Australia
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Cool. Its shiny and the spinniy spinny thing in the middle has lotsa blades. I love it. I'll take 3...
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Old Jul 06, 2011, 07:51 AM
Airplane crasher
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USA, CT, Shelton
Joined Jan 2008
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JimDrew why do you have your knickers in a bunch about the patent? Are you disturbed that someone else has come out with an alloy EDF unit that might give you compitition?
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Last edited by CapMike; Jul 06, 2011 at 07:57 AM.
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Old Jul 06, 2011, 09:12 AM
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maghull , merseyside
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EPF Hobby - why cant i order these new units off your website. Is there a problem.?
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