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Old Mar 10, 2012, 06:19 PM
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United States, GA, Buford
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Build Log
7" Zipper: 24mm

So here it is: my intended speed entry. I'm only a couple months late.

Specs:
Wingspan - 6.89" (175mm)
Length (without vert. stabs) - 11.42" (290mm)

Intended Components:
Receiver - Rx33
Servos - AS2000LBB (with diodes)
ESC - Plush 6a Lightened
Motor - 1015 11500kv
Fan - My own NDF24 with rotor
Battery - Anything but Nanotechs


The shape is an original ogival design that I came up with during the creation of the Chimera. (I was one of the original designers. ) I made it with a layer of white cellfoam (bottom) and a layer of grey depron (top), both of which are 3mm giving a total thickness of 6mm. I am going to round the leading edges and taper the trailing edge.

Now here is where I would appreciate some advice. It is still in the folded state. The two halves are only attached by the skin of the grey depron. When I drop it grey side down, it has a slight dihedral which lets it float down flat. Now when I drop it white side down, it has a slight anhedral which makes it ridiculously unstable.

I definitely would not give it anhedral, but what about giving it a slight dihedral? I don't plan on flying inverted. Heck I barely plan on flying the thing.

I trimmed the wing edges to the way they are supposed to be. The wing weighs 6.45g so far.
Yes it will have a fuse.

Kev
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Old Mar 10, 2012, 11:47 PM
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I still haven't glued the seam, cut the elevons, or sand the LEs.
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Old Mar 11, 2012, 03:04 AM
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Old Mar 11, 2012, 06:29 AM
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Ha, nice! That plane looks a lot like the plane I'm thinking of to build next.

Now I know the design has been done before, I'm sure I'll be able to get one to fly too.
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Old Mar 11, 2012, 11:25 AM
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Reminds me of the "Rayfish" and the "Shuttlefish" Metroidrc and I did several years ago.

http://www.rcgroups.com/forums/showt...hlight=rayfish

Flew pretty well.

Flat airfoil worked fine. You might want to consider a thrust tube and some intake fairing for the motor, to help with thrust and drag.

Also, we found that if you fair the edges of the EDF cutout, that helps with the airflow.
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Old Mar 11, 2012, 11:37 AM
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Flat airfoil worked fine.
I have a much thicker leading edge when comparing the size of the planes though.

You might want to consider a thrust tube and some intake fairing for the motor, to help with thrust and drag.
Definitely. I'm still waiting on the fan though.

Also, we found that if you fair the edges of the EDF cutout, that helps with the airflow.
Already started.
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Old Mar 11, 2012, 05:29 PM
Effumall
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This thing is the same idea. It was a 40mm deal, and was very fast...
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Old Mar 11, 2012, 05:43 PM
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Kool, what was your auw? I'm trying to stay below 40g, but then again mine is much smaller. I wonder if 50mph is feasible? My objective is to keep up with my friend's stryker which does about 50 or so level.
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Old Mar 11, 2012, 06:11 PM
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The elevons have been cut, but I forgot to bevel the trailing edges before I put the control horns in. They are a little small so I am worried about slow speed handling. What do you guys think?

I started rounding the top. I might just leave the bottom straight.

The underside will receive a black "fuse" plate along with either one large fin or two smaller and longer fins. I'm worried about sliding.

I must say, this is probably the sleekest model I have ever conceived.
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Old Mar 12, 2012, 07:54 AM
Effumall
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I think the AUW of the "Mirage" was maybe 60-70 grams? Again, it was a 40mm fan with a Feigo inrunner on 3S. Used Bluebird servos. If I redid it, I'd make it 30mm, and use PZ micro linear servos. The problem is with a high wing loading and not much span, it wants to roll like mad.

I bet you'll easily do 50MPH, if you can keep it stable.

BTW, is your fan going to sit on top, or will it be halfway down? If it's down in the middle, you'll probably want more area in the intake cutout. I experimented with a "NACA" shape, but ultimately found a "U" shape worked best.
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Old Mar 12, 2012, 08:56 AM
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And this one was a 55mm thing. It was a floater.
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Old Mar 12, 2012, 09:21 AM
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It is going to sitting on top.
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Old Mar 12, 2012, 10:23 AM
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???
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Old Mar 12, 2012, 10:45 AM
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Quote:
Originally Posted by kelberts View Post
is your fan going to sit on top, or will it be halfway down?
...
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Old Mar 12, 2012, 11:22 AM
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Thanks. Things make sense now.
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