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Giant Delta! 86 inches!! - 1/14/2003 1:39:28 PM   
CrazyHerb-RCU-delete



Posts: 391
Joined: 3/13/2002
From: CA
Status: offline 		Hi Guys,
Just thought I'd toss this in here...

Amazing! $7.50 worth of foam flies SO good.
On a .47!!!

http://www.rcuniverse.com/forum/fb.asp?m=473044&s=#473044

Posted Video to my web site...
http://home.attbi.com/~sherbertson/

Enjoy!!
CrazyHerbb

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Giant Delta! 86 inches!! - 1/14/2003 1:50:45 PM   
BMatthews



Posts: 8888
Joined: 10/4/2002
From: Burnaby, BC, CANADA
Status: offline 		It's so slow and large it reminds me of the Avro Vulcan doing it's flyby when it was at the Abbotsford airshow when I was a kid.

So simple but so good.

Might just have to follow in yer footsteps.

How about some measurements? Chord and stuff?.... oh never mind. The foam is only 2 feet wide so I imagine that it was aerodynamically engineered and by some amazing coincidence the aerodynamically ideal chord came out to exactly 2 feet..... Do I win a prize?

Just let me crash my PBF and I'll get right onto one of these....

Oh, what about airfoils? How much did you shave off there on the leading and trailing edges? I know it's not critical but you obviously sliced off a wedge with a kitchen knife or something.

PS: Oops, looking at the pics on your web site I saw a joint. So what IS the root chord. And it's not that big a deal but you might as well toss in the tip chord too.

< Message edited by BMatthews -- Jan 14 2003 8:56AM >


_____________________________

Bruce-
Proudly wasting balsa since 1965.

Free Flighters go that extra mile........

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Hint.... - 1/14/2003 2:52:14 PM   
CrazyHerb-RCU-delete



Posts: 391
Joined: 3/13/2002
From: CA
Status: offline 		Hint...those are full-length yardsticks in the pics...
I'm guessing around 40 inches..maybe 42...

Ya know...hadn't thought about it...but it does kinda have a lumbering...menacing "Vulcan" look to it....not intentional...but cool, none-the-less..

Tips are 10 inches NOT including 3 inch elevons. Made from 3/8x4x48 sheets.

I hot-wired the taper paralell to the chord (from root to tip) symetrically at the rear about 6 inches from trailing edge, left it about 1/2 inch thick. The leading edge is flat-bottom style with just a hint of lower at the tips to get a little washout effect. I did round the bottom leading edge just a tad...like 1/4 inch...but for the most part its a FLAT wing...

If you look at the first post (scroll up on the RCU link above I have a pic of what I did withthe foam... cut the sweep and added the cut material to the front... you can build TWO of these from a 4ftx8ft sheet of 2 in foam if you do it right....was 12.99 at Home Depot. So, about 7 worth of foam...

I'll see if I can take a couple pics of the tip and post here...

Good Luck!
CrazyHerb

< Message edited by CrazyHerb-RCU -- Jan 14 2003 10:20AM >

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cg - 1/15/2003 7:31:47 PM   
3dmagic


 

Posts: 83
Joined: 6/13/2002
From: sulphur, LA, USA
Status: offline 		where is the center of gravity, i gotta build one

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Giant Delta! 86 inches!! - 1/16/2003 1:14:21 AM   
TomJacoby


 

Posts: 44
Joined: 11/25/2002
From: High Rolls, NM, USA
Status: offline 		Excellent!

Very similar to the "Moonlighter" kit that was available back in the '80s - made from blue construction foam, IIRC.

Here's the one I built.

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Giant Delta! 86 inches!! - 1/16/2003 1:18:30 AM   
TomJacoby


 

Posts: 44
Joined: 11/25/2002
From: High Rolls, NM, USA
Status: offline 		More on the Moonlighter:

Fox .35; sliding tray mixer; half-round balsa LE; trike gear.

Needed a bunch of reflex (up elevator) and flew nose-up. Fairly gentle, moderately fast, poor glide.

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CG and Glide - 1/16/2003 3:34:45 AM   
CrazyHerb-RCU-delete



Posts: 391
Joined: 3/13/2002
From: CA
Status: offline 		The Center of Gravity is around 22 inches from the TRAILING edge (not rear of the elevons). It's a conservitive, slightly nose heavy CG but still working great. About 20% MAC.

The glide on this thing is INSANE....real floater. I had a dead-stick at about 500 ft and it took two minutes to glide back to my feet.

One thing to mention about Delta's. They are VERY efficent in straight and level flight. However, as soon as you bank or climb hard they loose it.

There is NO spar in the Giant Delta...but I did run a single 3 inch wide length of fiber strapping tape from tip to tip...where the sweep meets the tip. The wing is strong enough, but if I were to do it again...(and I will)..I'd run a 3/8 inch square hardwood spar just for added security.

I did try a flat spin with the HUGE rudder, but due to my nose heavy condition it will just do a big super-flat circle. That tip just WON'T stall! Also, need to increase my throw on the rudder a bit..I think it's only about 20 degrees...didn't want the plane to freak out on the first flight.

Let me know if anyone is going to build one...I'll try to answer any questions.

Good Luck!
CrazyHerb

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building - 1/16/2003 4:50:28 AM   
3dmagic


 

Posts: 83
Joined: 6/13/2002
From: sulphur, LA, USA
Status: offline 		i am going to build one soon do you have any close up pics of the wing thanks for the help

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Cool!~ Someone's gonna make one! - 1/16/2003 5:22:06 AM   
CrazyHerb-RCU-delete



Posts: 391
Joined: 3/13/2002
From: CA
Status: offline 		3D!

I'm away from home this week. But when I get back I'll get a little web page built on the construction and some close-ups.

Post here if you have any really big questions...We'll share with all!!

Can't wait to get a fleet of these big ol' things flying....

INVASION of the Giant wings!!

CrazyHerb

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Started mine - 1/23/2003 11:53:41 PM   
VoughtF4U



Posts: 359
Joined: 1/4/2002
From: Gray, TN, USA
Status: offline 		Crazy Herb,

I started mine last night. I have been looking for simple foam designs to build. I have to keep up my reputation at the field for bringing crazy but cheap airplane designs to the spring funfly. I am using half the 4x8 sheet for this delta and the other half will be used for a 4x4 semi-scale Vought V-173. It is basically a big flying pancake with two big props.

The foam I bought at Home Depot was 2 inch thick, but it was pink and cost about $22 a sheet. Not as cheap as your but it will still work. I also noticed on my foam sheet, it was pre-scored so that you could break it into strips. The scores run spanwise on mine so they really shouldn't be a problem. I will be using a zig zag pattern of fiberglass reinforced tape similar to that used on a Zagi flying wing. I plan on using an old Saito .65 four stroke that looks like it is on its last legs.

For the V-173, I plan on breaking the foam into strips at the score marks, gluing it all back together with luan ribs inbetween the strips, sanding it all down to shape and then fiberglassing the whole thing, latex paint for color. It will be a little heavier, but not much.

Thanks for the idea...

_____________________________

"Mix ignorance with arrogance at low altitude and the results are almost guaranteed to be spectacular"

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86" or 96" - 1/27/2003 8:50:59 AM   
Ralph V


 

Posts: 96
Joined: 10/17/2002
From: Menominee, MI, USA
Status: offline 		Crazy Herb

Your big delta looks great. But looking at the drawings you
show it as 96". 48" to the center, did you cut 5" off of each
tip to make it 86" wing span? Also on the drawing the wing
tips come out to 6".
What size servos did you use? And what size engine did you
use, and do you have any landing gear on it?
I like it, and want to build one next week end.

Thanks
Ralph V

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Corrections to plans - 1/27/2003 10:09:12 AM   
CrazyHerb-RCU-delete



Posts: 391
Joined: 3/13/2002
From: CA
Status: offline 		Oh Ya! Ralph, good catch... YES I clipped 5 inches from each tip and the tip chord is about 10 inches. The drawing was done before I acutally built it....

I used HS-700 1/4 scale servos (rudder, 2 elevons, 1 standard for throttle)but you could use standard high torque I imagine...maybe even standards.

The airframe is only 6 lbs even with the big servos. So not alot of mass to have to move...but the surfaces are BIG so I wanted to make sure....and they were just sitting in my servo drawer.

No landing gear....I'm going to mount a lite ply plate on the bottom and play with that though....just wanted to get it to fly first...didn't know it was going to fly so well!!! Now I can explore options....

Maybe even a beefed up version with a chainsaw conversion....42 cc or whatever I stumble on!

Thanks for the catch!!
CrazyHerb

Plans can be found here:
http://home.attbi.com/~sherbertson/

< Message edited by CrazyHerb-RCU -- Jan 27 2003 7:05AM >

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Giant Delta! 86 inches!! - 1/28/2003 5:49:27 AM   
Gordo-ProBro



Posts: 1984
Joined: 9/3/2002
From: Tulsa, OK,
Status: offline 		Hey CrazyHerb, I'm thinking of building a wing like your's, thanks for the info. I used 4x8 sheets of 1" foam for the XXXXXLarge PBF. The wing you built could be cut in one peice if the foam quality is similar. Do you know if there is a difference in the 2x4 type?

Thanks
Gordon

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Our Big Delta - 1/28/2003 8:20:09 AM   
Ralph V


 

Posts: 96
Joined: 10/17/2002
From: Menominee, MI, USA
Status: offline 		Crazy herb

Thought you might like to see a picture of the Big Delta
that My sweet heart and I built a couple of years ago.
Its about 9 feet in length, 82" span, and weighs 26 lbs.
Power is by a 30cc Glow engine.

Ralph V

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