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Old Dec 05, 2012, 05:25 AM
The blade numbers go up to 11
stumax's Avatar
Sydney, Australia
Joined Aug 2002
4,387 Posts
If you wanna talk powerhouse fans, here's something I've been working on all year, the SM120-63. 120mm rotor dia, 63mm hub dia, which means it only has 8192sqmm FSA, yet it puts out close to what a 127mm fan with around 10,200sqmm FSA does at the same power. It's the same rotor as on Joe's 120-56 (which gives about 7.4kg thrust on 4500W, 8.8kg on 6kW) , but with a larger dia motor tube.

It's got a few very special things about it which set it apart from anything else out there. Most noticeable is the motor tube design. Notice it has a bearing housing at the front, supported by 6 legs. The motor is a custom made 6 pole motor which uses 6 screws to screw it into the motor tube, there's no front bearing cap on the motor, the bearing is in the front of the motor tube. This gives the setup immense rigidity and allows for huge cooling holes in the front to pass air thru the motor. It has the benefits of having the motor built into the motor tube without the disadvantage of not being able to change it if it melts or you wish to try another kV or length. Like all my other fans, the motor case is a precision fit inside the motor tube and uses thermal grease to help thermal conductivity. This one uses 9 stators, which gives the shroud a lot of extra rigidity.

Performance is right up there, 6kW gives 8.6kg (almost 19lb) thrust, 4.5kW gives about 7kg (15.5lb) thrust. Comparing these numbers to a 127mm Dynamax or Ramtec fan, don't forget it has about 80% the FSA of a 127mm fan, and so its static thrust should be about 90% (ie square root of 0.8) of their values at the same power. As it only has 8192sqmm FSA it can handle smaller inlets and smaller exhausts. The motor in this one can handle 8kW or so (possibly more, I need a better esc to go up there), which will net about 10kg (22lb) thrust, with about 250mph exhaust velocity at 100% FSA. AUW with this motor is 1120g. There's a shorter motor option which is about 200g lighter and can go up to about 6kW, but for those power levels the 120-56 is a better choice (even lighter), the HET800 series 680kV motor works very well on 12S, same as the Neu 1915-1Y in Joe's one.

I'm planning to make it available before Christmas if I can get my component suppliers to play ball, price should be around the $450-480 mark + motor, depending on my actual manufacturing cost.

Stu.
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Old Dec 05, 2012, 05:29 AM
Registered User
Singapore
Joined Nov 2007
436 Posts
Fantastic Stuart a real animal of a fan, now we have the perfect solution for all those P-80 size models.
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Old Dec 05, 2012, 08:48 AM
Pursuit of Happiness
Ron101's Avatar
Brentwood, California
Joined Jul 2007
7,256 Posts
Wow Stu! that looks amazing and really strong numbers.... I know from flying the smaller versions just what a speacial design you have here. I could only imagine that bad axx sound this thing is going to make

very cool!
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Old Dec 05, 2012, 10:56 AM
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bri6672's Avatar
San Diego
Joined Jul 2009
2,281 Posts
Stu, be sure to include amps when you talk about your fans! Amps give me an idea of what kind of mah I need to run to get reasonable flight time, I have your SM 100-45 and love the lower amps it pulls in relation to the power. For me I'm trying to get the most thrust and efflux with the least amount of amps! That Ramtec setup sounds good but you should test it with a thrust tube and establish some numbers similar to it installed.
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Old Dec 05, 2012, 01:18 PM
Jets fly goooood!
felix72's Avatar
Italy, Lazio, Ariccia
Joined May 2004
569 Posts
I think this is what I was dreaming for since 2 years!
So far look great Stu, let us know more about the availability and I think this fan needs a dedicated page.

Regards
Gianluca
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Old Dec 05, 2012, 01:38 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
WOW, that baby looks good.
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Old Dec 05, 2012, 02:05 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
21,165 Posts
i was very impressed with Joes fan when i had it in my hands during the custom fitment of this fan into one of my nacelles .nice work Stu...and i bet your blades WONT blow apart.
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Old Dec 05, 2012, 02:19 PM
aka JetMan Joe
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Joined Feb 2010
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I am so happy to be Joe right now, Thanks for everything Stu
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Old Dec 05, 2012, 03:54 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,723 Posts
Quote:
Originally Posted by AIR SALLY View Post
thats what i was thinking too ,back in the day i played with longer stators on the turbax and larry and i felt that it helpd with thrust and speed.im sure his alloy shroud has less startors than a Ramtec fan ,and they may be shaped different. the 590 kv could account for the lower amps...i think he just has a great set up there ,those are great thrust to amp numbers.
Actually afaik the current ramtec electric units all have 6 stators, same as my housing. The 590Kv motor is a brilliant motor, and its well priced, allows me to make the complete fan ready to plug in for just under $500. I have been working closely with Tony on the rotor setup specifically the collet, the rotor fitment is very easy and with the way he assembles and trues them they run really well straight out of the box, I make any final dynamic balance adjustemts that may be needed with the spinner cap only.

I just finished another fan last night for a local customer, its all ready to plug in for final dynamic balance, comes in at 1090 grams complete with the heatsink motor cover. Note the bullets are only there for easy connecting to the test stand setup! Scuse the poor photo, was ony a quick snap.
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Old Dec 05, 2012, 04:05 PM
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bri6672's Avatar
San Diego
Joined Jul 2009
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Quote:
Originally Posted by Extreme_RC View Post
Actually afaik the current ramtec electric units all have 6 stators, same as my housing..
Ok so how do you explain the lower amount of amps your getting??? Everyone that is a large EDF enthusiest knows that the Ramtec has always been an amp hog! If you have changed something in the design of the stator, that would make sense.
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Old Dec 05, 2012, 04:49 PM
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Arngeir Blakseth's Avatar
Molde, Norway
Joined Jan 2001
2,464 Posts
The Ramtec works perfectly fine, with the right motor. I am running one with a Neu 1917 1Y 590kV (HET 800-73-590 looks like a copy of this motor) and I get very good results. Using Hyperion 35C 6500mAh batteries it pulls 115-120A on 12S and the performance of my 19lb Falcon 120 was really good. Now, what people need to understand is that while this is a 5" fan just as the Dynamax fan, the same kV motor will not work in both fan units, the Dynamax works very well on 12S with a 650-700kV. The Ramtec needs a lower kV motor as it is a harder load on the motor, so use the wrong motor/too high kV motor and it will be an amp hog. It is not any harder than that, really.

And yes, my Ramtec also has 6 stators and this is an early version that predates the ones with a 5035 Scorpion motors so I think all EDF Ramtec units have had 6 stators.
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Old Dec 05, 2012, 06:04 PM
Extreme CNC Alloy EDF
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Australia
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Thankyou Arngier! I think you explained it perfectly.
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Old Dec 05, 2012, 10:27 PM
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San Diego
Joined Jul 2009
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Quote:
Originally Posted by Arngeir Blakseth View Post
The Ramtec works perfectly fine, with the right motor. I am running one with a Neu 1917 1Y 590kV (HET 800-73-590 looks like a copy of this motor) and I get very good results. Using Hyperion 35C 6500mAh batteries it pulls 115-120A on 12S and the performance of my 19lb Falcon 120 was really good. Now, what people need to understand is that while this is a 5" fan just as the Dynamax fan, the same kV motor will not work in both fan units, the Dynamax works very well on 12S with a 650-700kV. The Ramtec needs a lower kV motor as it is a harder load on the motor, so use the wrong motor/too high kV motor and it will be an amp hog. It is not any harder than that, really.

.
Well aware of the different kv required per motor, thrust for thrust just saying it doesn't seem to add up amps or performance, that said only can compare higher power setups.
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Old Dec 05, 2012, 11:11 PM
Extreme CNC Alloy EDF
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Australia
Joined Mar 2006
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Its pretty clear in the video what the figures are.
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Old Dec 05, 2012, 11:21 PM
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San Diego
Joined Jul 2009
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Quote:
Originally Posted by Extreme_RC View Post
Its pretty clear in the video what the figures are.
Dude your not listening... I said Great, Sounds Good! I just have not liked the way it flew and we needed a lot of amps to get the 20lbs of thrust we were looking for on 12s. That's it, just my opinion, sell the heck out of them have fun, I just prefer the Dynamax, Turbax and DS-94 HST over the Ramtec....
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