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Old Mar 13, 2009, 08:38 PM
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Ohio Combat/Babylon AD Ducted Fan Wing

A few months ago I posted some pics of a ducted fan wing from the movie Babylon AD. I did not think I could put it together, but with Jeremy's help, I present the first Ducted Fan Guillotine.

Although its finished and ready to maiden, much like Casey, I will have to wait for the weather to break in my new location. I also need to make it look more like the Babylon AD drone, but I think I may try to fly it first.

I have 3 other Guillotine cores; one for slope, one for speed, (though not a beast like Casey's), and one for whatever.

I want to thank Jeremy for his help, his teaching, friendship, totally amazing wings and many other soon to come projects.
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Old Mar 13, 2009, 09:22 PM
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Dublin Ca
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Nice concept hope it clears up for you soon so you can see how it flies..

I'm not a big Fan of Fans They just don't seem to have the low speed power a prop driven plane does... I recommend you make a bungee launcher to get it up to on step during your launch...

Also you may find that a efflux tube will be required to get the fan air movement up to a reasonable level.. 80 to 85% reduction is normally enough and 3 to 5 inches past the stock fan housing would be long enough to have decent effect

A clear efflux tube would not take away from the look too much
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Old Mar 14, 2009, 11:10 PM
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Troy ,OH
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Hey Galo,Looks like your getting settled in. I was wondering whether you had flown the DF wing yet.
As for the fan he's using a hyper flow with the recommended setup. If I recall correctly it has plenty of thrust. The is about 85%. My only concern is down thrust issues. The fan was mounted 50-50 so it may need some manipulation in order to correct any positive or negative issues. The glide ratio on the Guillotine is very good and will be very easy to get airborn and only shy about .25 from being 1 to 1.
Jeremy
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Old Mar 15, 2009, 01:50 AM
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Fricken sweet man!!! I hope i get the "beast" up and running tomorow. The weather is getting better as it will be 50 or so tomorow. Maybe some vids as all is good.

Nice guillotine EDF!!! I like i like.

casey
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Old Mar 15, 2009, 01:53 AM
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that battle axe reminds me of my first guillotine. Same color and everything. Love the stripes.

casey
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Old Mar 15, 2009, 02:18 AM
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Still up Should have some nice weather coming soon.
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Old Mar 15, 2009, 02:17 PM
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Quote:
Originally Posted by grumman5277
As for the fan he's using a hyper flow with the recommended setup. If I recall correctly it has plenty of thrust. The is about 85%. My only concern is down thrust issues. The fan was mounted 50-50 so it may need some manipulation in order to correct any positive or negative issues. The glide ratio on the Guillotine is very good and will be very easy to get airborn and only shy about .25 from being 1 to 1.
Jeremy
Sorry if i offended you Jeremy

I was only speaking from experience I had attempted a edf version of the 36 inch rw and I was very disappointed in the fan I was running a hyper flow and a jet screamer motor on 3s just just did not have the Umpf i liked.. maybe if i had tried 4s but i hated the amp draw it was causing

The motor will produce more fan speed and less thrust with the eflux tube but the amount of thrust lost is negligable compaired to the ammount of air speed gained..

I spent quite a few nights in the EDF fourm and talking with the fan guys to find the balence that was needed for the combo i was running..

I did do my homework..
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Old Mar 15, 2009, 05:15 PM
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Nope nothing to get offended by.

This fan is said to have about 16oz of thrust with the recommended motor and 3s.
I'm not sure if the claim is accurate or not but we designed the wing around the power train.The reason for doing so was to avoid as much as possible what you have stated.
The farther you get upside down on thrust to weight it becomes very clear.

We mounted the fan centered with the wing to avoid the pitching down issue I experienced with my delta's. As far as fans go I have a preference which wouldn't work with his plan and it's the HET 6904. I may build my own with the setup mentioned on the same wing using 4 or 5s.
Jeremy
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Old Mar 15, 2009, 05:34 PM
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Ya that might be the fans rating, but keep in mind that is with the intake ring with a clean inlet ,if you dont have the intake smooth and ub structed inlet you might just cut the numbers in 1/2.


The Sky Vak, does appx 120 mph,it has an efux tube sized to 80% of the inlet size.

All the perfomance areas were incorporated into the cnc routered design.
Getting EDF's to perform is a whol differant ballgame than a prop.

Here is a thread with som pix and info on Mark Woods version that has landing gear.
The project produced 4 kits and only 3 were built I have one more here 1/4 built still.
The two here that are rtf are so beautiful it is hard to even get out and fly.
I would just cry if I crashed one.

http://www.rcgroups.com/forums/showt...hlight=sky+vak

Ck






Quote:
Originally Posted by grumman5277
Nope nothing to get offended by.

This fan is said to have about 16oz of thrust with the recommended motor and 3s.
I'm not sure if the claim is accurate or not but we designed the wing around the power train.The reason for doing so was to avoid as much as possible what you have stated.
The farther you get upside down on thrust to weight it becomes very clear.

We mounted the fan centered with the wing to avoid the pitching down issue I experienced with my delta's. As far as fans go I have a preference which wouldn't work with his plan and it's the HET 6904. I may build my own with the setup mentioned on the same wing using 4 or 5s.
Jeremy
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Old Mar 15, 2009, 06:21 PM
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The hyperflow has a bell mouth inlet which is considered 0 static lose used in full scale commercial turbine testing . The coroplast sits behind the inlet and does not interfere with the inlet. We used leading edge type material for the inlet to reduce as much as possible losses due to having a blunt area in front of the fan.
Jeremy
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Old Mar 15, 2009, 09:54 PM
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I think this is what i was talking about.. I had the same problem on my FS36 EDF all flying wings that have not been designed with EDF in mind from the beginning and have a tube for the center of the plane have this same problem of getting enough air into the intake for great performance..

Im not saying it wont fly just that performance is going to be in the this is not fun to fly catagory.

If the wing gets in a postive or negitive alfa half the fan gets blocked from air...
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Old Mar 15, 2009, 10:40 PM
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Oddly i could not find any of the other pictures. I must have really suppresed this one..

I just wanted to show that it is hard to get clean air on any wing of this design..

Keep us posted and I hope that it proves out to be a fun and exciting wing to fly..

Best wishes..
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Last edited by PaulVi; Mar 15, 2009 at 10:49 PM.
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Old Mar 15, 2009, 11:04 PM
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Paul,

I understand your concerns about airflow, and I appreciate your advice.

The pictures really don't do it justice. There is really a fairly clean intake into the fan, and the coroplast outlet functions like a tube, though its not a perfect circle.


Its covered in Solartex, and I want to paint it. I'm afraid if I fly it now as a single color, I may get confused and crash it.

I'll try to get painting this week sometime, and will update after a maiden.
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Old Mar 15, 2009, 11:07 PM
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still having pc issues. have to hold down the fn key just to type.
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Old Mar 15, 2009, 11:43 PM
Mum is the word!
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Not trying to be a meathead,but from messing with edf's extensivly .
I have found anything up that close to the fan inlet causes a major performance drop.
The wing shadowing the fan can be a real issue as Paul says
I also have found that the hyperflow fan works way better if ballanced well..

Good luck edf's in a wing ,it is a total chalange to get somwhat decent performance.
ck
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