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Old Feb 12, 2012, 12:34 PM
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karoliinasalmin's Avatar
Finland, Espoo
Joined Jan 2012
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Quote:
Originally Posted by lhb009 View Post
I am in the process of building a 5' EDF flying wing(EPP foam). I have built about 30 pusher flying wings, but I have never built or flown EDF models. What key differences would you point out? In addition to my flying wings I have built, more than a dozen balsa buildup, gas/Electric/sailplanes.

I plan to make it 5' span, weigh less than 4 lb, dual EDF units on the top rear where the prop normally would be. How big of EDF units should I start with? I was considering 60-90mm units. I will be flying it with a DX6i, with HS 82mg servos. Is there anything else I should know prior to buying electronics?
I have to first admit that I am less experienced than you, especially about flying wings. I have only assembled couple of Multiplex Xenos. However, I have tried this:
- I have flown Xeno with similar than the stock motor and prop
- I have flown the Xeno with an insane motor (it achieves flutter speed in level flight)
- And I have flown the Xeno also with 68mm EDF with 4S battery

The difference between the prop flying and EDF flying is mainly that the EDF does not have that bad P-factor and the tendency to roll on launch does not exist with EDF. The EDF version goes straight and the flying qualities are very pleasant.
Launching the EDF-version was a little bit harder because less static thrust available. However, taking this in account, the EDF-Xeno can be hand-launched almost identically than the prop Xeno (the more normal motor version with reasonable thrust).

I am flying now also some EDF jets and in general I think they are easier to fly than the prop planes because they go straight and do not suffer from the P-factor nor from the prop wash over the wing and tail. EDF is a bit like pusher propeller but with less static thrust. Electric Ducted Fan does not take much time to spool up, it is not like turbine. Instead it is a small diameter propeller in a duct really and there is no magic. The prop efficiency of a typical EDF is lower than that of a prop without the duct around it largely due to the fact that typically the EDFs have small diameter and the basic rule is that it is better to increase the speed of greater air mass a little than increasing the speed of a little air mass a lot. EDF does the latter.

EDF plane is easier to fly if there is enough thrust on the EDF system. That usually means that the EDF diameter is as large as possible.
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Old Feb 15, 2012, 10:49 AM
Crash Pilot
USA, UT, Provo
Joined Oct 2010
24 Posts
Thanks for the input and info on EDF vs Prop differences. That will help me a lot. I cut out a prototype wing, and it looks great. The reason for twin EDF units is just for asthetics, and I think if I am running 3 cell packs it will give me plenty of thrust. I have found several EDF units on Hobbyking, but I dont really know which ones to trust. Any prefered units when running on 3 cell packs?
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Old Feb 18, 2012, 11:36 PM
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United States, CA, Lancaster
Joined Feb 2012
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Banana Hobby, Always use a credit card!! lession..

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Last edited by Edwards Rc; Mar 23, 2012 at 11:44 PM.
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Old Apr 09, 2012, 09:00 AM
An itch?. Scratch build.
eflightray's Avatar
South Wales U.K.
Joined Mar 2003
13,399 Posts
Ok, so it's not the 'F' part but the 'P' part, but still ducted.

This was my first attempt at a ducted jet, not exactly EDF but EDP, (so some fans have 3 blades, as do my props).

But, it shows that relatively low power and light weight can work.

Though the, "it has to go faster than anything else.." EDF fliers may disagree

My version of a non-scale Mig 1.42/1.44 as an Electric Ducted Prop project.

Plus a hand launch from a standing start, (just after the 4 minutes in ).


Mig August.wmv (5 min 34 sec)
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Old Apr 17, 2012, 11:23 AM
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United States, FL, Sarasota
Joined Dec 2010
331 Posts
64mm are so underpowered!! 70mm jets have extra power! my habu has too much power. Any sport jet design like a dynam meteor or habu for example will always have extra power to get out of trouble. I like to run my 70mm on 4 cells maybe even 5 cells..
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Old Apr 17, 2012, 02:17 PM
You win again gravity!
SMorrisRC's Avatar
UK
Joined Jan 2010
1,253 Posts
My 64mm F22 has plenty of power!

Portishead EDF 11/03/2012 - Starmax F22 and Sabre (4 min 9 sec)
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Old Apr 17, 2012, 02:30 PM
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United States, CA, Lancaster
Joined Feb 2012
201 Posts
I don't know about the airplane... but your flying location is awesone.. were is this location.. flying above the marine layer.. very cool..
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Old Apr 18, 2012, 03:21 AM
You win again gravity!
SMorrisRC's Avatar
UK
Joined Jan 2010
1,253 Posts
It's in the UK on the west coast. An unused pitch and putt golf course, so not very flat but great views. Shame we won't be able to use it soon.
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Old Apr 21, 2012, 08:05 AM
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buffalo n.y.
Joined Jul 2009
79 Posts
great forum for beginners like me
my problem not enough power
i had f9f from banana hobby tried to hand lunch
all it did was to try to hover and float then stall and crash
other planes hk t33 eflight f86

is there a us or German war jet that has good hand lunch
thanks
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Old Apr 21, 2012, 01:10 PM
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Qtop's Avatar
Denmark
Joined Apr 2011
518 Posts
One of my first flights with a EDF plane. More then enough power to go unlimited vertical.
Landing was a not so smooth, but still in one piece.

Power source: HET 2W-20 + HET FAN

Hobbyking T-50 HET 2w-20 + Fan (3 min 57 sec)
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Old Apr 25, 2012, 01:53 AM
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xfatdannx's Avatar
United States, NE, Omaha
Joined Feb 2012
978 Posts
I just got an a-10 for my first edf. still in the build stages. i read this is a good starter for edfs. would you agree disagree and why?
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Old Apr 26, 2012, 02:37 PM
I like Fast Warbirds
Webmaister's Avatar
United States, GA, Atlanta
Joined Nov 2011
477 Posts
Quote:
Originally Posted by brunobrazil View Post
Another great first EDF is the Parkzone Habu. Since nobody has remebered it before in this thread, here comes some nice Habu photos!




Agree on that. My first was it's sister the Dynam Meteor. Liked it so much I have two now and am buying a third. Each one has different mods. Here's my X2 prototype mod. It's powered by an 1800 watt WM400MK II fan.

Dynam Meteor X2 Project Video I (5 min 49 sec)
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Old May 23, 2012, 07:12 AM
Jet-Addicted!
United States, SC, Greenville
Joined May 2012
170 Posts
Sorry if this post is a little late... ADVICE??

Can someone shed some light on the below for me?? I am currently looking at buying the F-14 twin-60mm EDF... I got so hung up on the coolness of the swing-wings that I MISSED the fact that the airframe does NOT come with working ailerons!!

Question 1) You suggest below that the plane NOT be set up with elevons.. Well, since the plane Has No ailerons, how can you NOT set the plane up for elevon-configuration?? (short of custom-installing a set of working ailerons)??

Question 2) Since you seem to know a good bit about this plane, can you describe flight characterisitcs in ALL configs, meaning A) "standard, no-aileron, B) ailerons, NO elevon-setup, and then ailerons AND elevon (optional) setup..

many thanks in advnace for any input. Again, I'm pretty enthralled witht he F-14, however I'm also sure I'll be flying a 50mm F-16 and then 70mm FA/18 since they're pretty forgiving airframes.. after I get used to those, I'll attempt the F-14.. meanwhile, the F-14 LOOKS AMAZING - I'm still so impressed at the tech-advancement that allows for us to enjoy such COOL toys.. Again, TOY is the key-word, I think I have the correct expectations with EDF's and that's why I'm pretty sure I will A) LIKE THEM and B) NEVER criticize them as being underpowered.. I'm not expecting yank/bank turn and burn - I think I have correct expectations out of the model..




Quote:
Originally Posted by Maxthrottle View Post
Keep the wings extended and get used to it. Don't setup up the stabilators (rear elevators for pitch only) as Tailerons (rear elevator as pitch and roll surfaces) till you really get used to it. The F14 was bad for flat spins and lateral departures.

When you get around to swinging the wings the centre of lift moves back so the model will dip down some. Mix in stabilator ~1-2mm to pitch the model up more as the wings sweep back.

The wing load is a bit higher on this model so keep some speed up and make a conscious effort not to over correct.

Don't freak out too much. Really. That just leads to brain freeze, I meant to go up not down, left not right sort of stuff. For everyone each new model is new to them too. Some may have refined their skills to deal with it and by experience have an idea what may be happening before it goes all wanky

Fly something else before you fly this just to self check that your head is in the right space.

Have fun and learn a little at a time if it seems like a handful. Fly over tall grass works for me specially for hand launching.
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Old May 31, 2012, 02:29 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,471 Posts
Quote:
Originally Posted by NickFox View Post
Can someone shed some light on the below for me?? I am currently looking at buying the F-14 twin-60mm EDF... I got so hung up on the coolness of the swing-wings that I MISSED the fact that the airframe does NOT come with working ailerons!!

Question 1) You suggest below that the plane NOT be set up with elevons.. Well, since the plane Has No ailerons, how can you NOT set the plane up for elevon-configuration?? (short of custom-installing a set of working ailerons)??

Question 2) Since you seem to know a good bit about this plane, can you describe flight characterisitcs in ALL configs, meaning A) "standard, no-aileron, B) ailerons, NO elevon-setup, and then ailerons AND elevon (optional) setup..

many thanks in advnace for any input. Again, I'm pretty enthralled witht he F-14, however I'm also sure I'll be flying a 50mm F-16 and then 70mm FA/18 since they're pretty forgiving airframes.. after I get used to those, I'll attempt the F-14.. meanwhile, the F-14 LOOKS AMAZING - I'm still so impressed at the tech-advancement that allows for us to enjoy such COOL toys.. Again, TOY is the key-word, I think I have the correct expectations with EDF's and that's why I'm pretty sure I will A) LIKE THEM and B) NEVER criticize them as being underpowered.. I'm not expecting yank/bank turn and burn - I think I have correct expectations out of the model..
Sorry. Don't even remember the context of my reply but if the stabs were pitch only you would have to add functional ailerons.
Since this thread is directed to newer pilots;
Elevons (pitch & roll) are flap control surfaces that are a part of the wing as in Deltas or say F-117 NightHawk.
Stabilators are all moving stabs in pitch only that are aft unattached to the wing.
Tailerons are full moving stabs in pitch & roll that are aft unattached to the wing.

So the F-14, 15, 16, 18, 22, 35 all have tailerons.

The 14 roll control is unique as the FS has spoilerons. They worked like all the other with the tailerons. Some believe tailerons to be problematic as. They may introduce a cork screw effect depending on the design but this is little different than the coupling you hear from 3D guys with basic Stab/Elv and Ailerons. You simple program differential to dial it out.
I can't recall what I was relating from my quote but if I had limited channels and was concern about getting used to an F-14 as a first EDF, I would add ailerons and fix the wings extended to have it fly a little more conventionally. Any coupling etc. isn't really something a beginner is going to see or need to worry about much because they're not pushing the model or doing lots of hard manuevers like the FS.

With any of the F-14s I'd add the aileron servos, which don't have to be big servo's since the tailerons are doing most of the work, but I'd set the wing servos as flapperons/spoilerons (for landing and wing extended roll) and use very light small servos. I'd also leave the tailerons always active and not switch between Stabilators wings extended, Tailerons wing retracted.
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Old Jun 04, 2012, 11:33 PM
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capt soap's Avatar
dallas tx
Joined Jun 2003
2,901 Posts
Max, Lockheed??? Boeing?
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