HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 17, 2011, 02:00 PM
Registered User
Falkland Islands
Joined Dec 2010
64 Posts
Discussion
formulae for flying wing design?

Hi there, just built a crude flying wing for slope soaring...which I am a total newbie at....its been test glided and while it does glide, sort of I just wonder if its a bit too hefty to be successful...winds are quite light at the moment but am aiming to head to a slope to see what happens.

I would guess that there is a rule of thumb for the design of these. I was just fooling about with some foam, tape and spare servos etc...but would like to take it more serious.

Seen a lot of ytube footage of wings, sure looks a lot of fun.

Rob
robwilkinson is offline Find More Posts by robwilkinson
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 17, 2011, 02:02 PM
EPP Extrordinare
Mr. Combat Certain's Avatar
United States, CA, San Clemente
Joined Feb 2008
3,325 Posts
Any pics? Specs (wingspan, chord lengths, weight, airfoil, etc)?
Mr. Combat Certain is offline Find More Posts by Mr. Combat Certain
Reply With Quote
Old Mar 17, 2011, 02:32 PM
Registered User
taurineman's Avatar
Wellington, New Zealand
Joined Sep 2009
395 Posts
meh, there's no such thing as too heavy for a sloper - only not enough wind...
taurineman is online now Find More Posts by taurineman
Reply With Quote
Old Mar 18, 2011, 02:02 PM
Registered User
Falkland Islands
Joined Dec 2010
64 Posts
err..no..the airfoil is not very good...it was all cut with a sharp knife...span is about 36 inch or so...weighing in at 800grams.

Took her up this morning where almost gale force winds actually made it fly...to a degree.

The airfoil is so poor that the control surfaces dont work too good had a heck of a job flying it yesterday...got a good glide in though...it was heading for a road so had to land her...could have sworn that there was a little ground effect going on there...just wouldnt land!

Totally bitten by the bug now, been flyin helis and planes for a few years...sold the helis..the more serious ones like the turbine etc...and cant be bothered with powered flight no more...just couldnt stop thinking of how my wing looked when it actually flew

Are there any plans that can be downloaded? I have a Perkins 'Bullet' glider in the post/....a friend of mine has one coming down as well as we are both real keen to learn. The Bullet is EPP so should be tough enough to learn on.

I live in the Falkland Islands, so plenty of wind and loads of slopes too!
robwilkinson is offline Find More Posts by robwilkinson
Reply With Quote
Old Mar 18, 2011, 02:41 PM
EPP Extrordinare
Mr. Combat Certain's Avatar
United States, CA, San Clemente
Joined Feb 2008
3,325 Posts
Hmmm...did you try and model a real airfoil, or did you just carve it until it looked ok? What materials are you using? Can you get a pic or two?

I taught myself mto fly with homemade wings from foamboard. I would buy 1/2" thick sheets, take off the paper, and sand it to look like an airfoil. They did fly, but performance wasnt so great. If your more interested in designing slopers, keep experimenting. I enjoy designing my own creations, but if your more into the actual flying aspect, then I'd suggest buying an EPP kit and building that.

Jordan

p.s., for free sloper plans, take a look here : http://www.rcgroups.com/forums/showthread.php?t=301997

Quote:
Originally Posted by robwilkinson View Post
err..no..the airfoil is not very good...it was all cut with a sharp knife...span is about 36 inch or so...weighing in at 800grams.

Took her up this morning where almost gale force winds actually made it fly...to a degree.

The airfoil is so poor that the control surfaces dont work too good had a heck of a job flying it yesterday...got a good glide in though...it was heading for a road so had to land her...could have sworn that there was a little ground effect going on there...just wouldnt land!

Totally bitten by the bug now, been flyin helis and planes for a few years...sold the helis..the more serious ones like the turbine etc...and cant be bothered with powered flight no more...just couldnt stop thinking of how my wing looked when it actually flew

Are there any plans that can be downloaded? I have a Perkins 'Bullet' glider in the post/....a friend of mine has one coming down as well as we are both real keen to learn. The Bullet is EPP so should be tough enough to learn on.

I live in the Falkland Islands, so plenty of wind and loads of slopes too!
Mr. Combat Certain is offline Find More Posts by Mr. Combat Certain
Reply With Quote
Old Mar 18, 2011, 02:42 PM
Gravity sucks
SrWade's Avatar
United States, WA, Richland
Joined Mar 2006
2,496 Posts
Check out this thread for a good discussion on airfoils and dimensions for combat wings.

http://www.rcgroups.com/forums/showt...t+wing+airfoil

Cutting a decent airfoil with a knife is a challenge, to put it mildly. You will get much better results using a hot wire foam cutter, which you can easily make yourself. There are many threads on this forum that describe different ways to do it. Or, as Jordan said, just buy one of the kits. They are not expensive, at least here in the states. Not sure what shipping to the Falklands would add. Welcome to the slope addiction!

Mike
SrWade is offline Find More Posts by SrWade
Reply With Quote
Old Mar 18, 2011, 05:45 PM
Registered User
slopemeno's Avatar
Joined Jan 2003
6,929 Posts
So, the Falklands huh? What's that like? Sounds like a slopers paradise to me.

If I could make a suggestion: Buy a Zagi or a Bee combat wing. They fly great, and will take a huge amount of abuse.

Anybody up for a Falklands Cup slope race? I need some time away from work right about now....I just need a few sponsors for the airfare.

edit: The Bullet should be OK for a first-foamie.
slopemeno is online now Find More Posts by slopemeno
Last edited by slopemeno; Mar 18, 2011 at 05:53 PM.
Reply With Quote
Old Mar 18, 2011, 07:48 PM
Registered User
Roo2's Avatar
Joined Aug 2007
231 Posts
If you can get hold of some coroplast this is a cheap and very good flying wing:
http://www.rcgroups.com/forums/showthread.php?t=229915
Roo2 is offline Find More Posts by Roo2
Reply With Quote
Old Mar 19, 2011, 04:51 PM
Entropy is happening!
Jim.Thompson's Avatar
Australia, NSW, Bellingen
Joined Aug 2008
6,787 Posts
Quote:
Originally Posted by robwilkinson View Post
.......................................
I live in the Falkland Islands, so plenty of wind and loads of slopes too!
It sounds like slope flyers paradise!

I would agree with suggestions you buy a good EPP kit. If and when you want to continue with designing and building your own, I suggest you do some homework reading up on plank and chevron (swept wing) airfoils.
A good flying tailless plane will have a good, well proven airfoil.

I look forward to further reports of you building and flying adventures. Sounds fantastic!

Jim.
Jim.Thompson is offline Find More Posts by Jim.Thompson
RCG Plus Member
Latest blog entry: Yet another light plank!
Reply With Quote
Old Mar 19, 2011, 06:21 PM
gizzo don't tweet
gizzo's Avatar
Adelaide, Australia
Joined Jan 2008
3,061 Posts
just for interests sake, I GoogleEarthed the Falklands for a look, picked a random bit of coast (Fox Bay E) and straight away found a 26km long DS ridge!
gizzo is offline Find More Posts by gizzo
Reply With Quote
Old Mar 19, 2011, 06:55 PM
Entropy is happening!
Jim.Thompson's Avatar
Australia, NSW, Bellingen
Joined Aug 2008
6,787 Posts
Quote:
Originally Posted by gizzo View Post
just for interests sake, I GoogleEarthed the Falklands for a look, picked a random bit of coast (Fox Bay E) and straight away found a 26km long DS ridge!
Yahoo! When are we going?

(I'll have to learn to DS first!)

Jim.
Jim.Thompson is offline Find More Posts by Jim.Thompson
RCG Plus Member
Latest blog entry: Yet another light plank!
Reply With Quote
Old Mar 21, 2011, 07:37 AM
Registered User
Falkland Islands
Joined Dec 2010
64 Posts
Hi guys, what a community here! sorry for the delay in getting back to you all...dont have the net in my house...and the office I use is shut over the weekend...so...

Gave up on the 'wing' and built another glider...hard to find the foam...used Polysterene slabs and made up a wing profile set...so straight wing with a pod and tail fin.

Initial glides were not bad but the pod was too fat and giving a lot of drag. it got its front broken in the end. Built a slimmer pod and made it more streamlined and added loads of ballast as the wind was quite strong...result was better glides but the CG issues need ironing out. Gave up as the wind was dropping...so went sailing (love wind related stuff like that).

Looking for more foam, made up a hot wire cutter for the current glider (scuse the pun) certainly the way to go in terms of building. My aim is to build my own design based on a Bird we have here, the Black Browed Albatross, a stunning bird and a great topic for a glider design..

I do have a 'Bullet' EPP foam glider kit coming down, a friend of mine has one coming down too...so we can learn together.

So...flight: you have to add weight to get the correct glide angle per se...then add extra ballast at the CG point of the wing...or under the CG ie the fuselage? I found that if the glider went backwards in the breeze, lift would diminish...adding the ballast made better progress of course...but really the ballast needs to be easily adjusted to suit conditions.

Plenty of sites to glide here in the Islands, Fox Bay is not far from my parents farm...same Island. Google earth 'Port Stanley' and 'Sappers Hill' ...I was on the western slope of this.

Rob
robwilkinson is offline Find More Posts by robwilkinson
Reply With Quote
Old Mar 21, 2011, 12:53 PM
EPP Extrordinare
Mr. Combat Certain's Avatar
United States, CA, San Clemente
Joined Feb 2008
3,325 Posts
Quote:
Originally Posted by robwilkinson View Post
Hi guys, what a community here! sorry for the delay in getting back to you all...dont have the net in my house...and the office I use is shut over the weekend...so...

Gave up on the 'wing' and built another glider...hard to find the foam...used Polysterene slabs and made up a wing profile set...so straight wing with a pod and tail fin.

Initial glides were not bad but the pod was too fat and giving a lot of drag. it got its front broken in the end. Built a slimmer pod and made it more streamlined and added loads of ballast as the wind was quite strong...result was better glides but the CG issues need ironing out. Gave up as the wind was dropping...so went sailing (love wind related stuff like that).

Looking for more foam, made up a hot wire cutter for the current glider (scuse the pun) certainly the way to go in terms of building. My aim is to build my own design based on a Bird we have here, the Black Browed Albatross, a stunning bird and a great topic for a glider design..

I do have a 'Bullet' EPP foam glider kit coming down, a friend of mine has one coming down too...so we can learn together.

So...flight: you have to add weight to get the correct glide angle per se...then add extra ballast at the CG point of the wing...or under the CG ie the fuselage? I found that if the glider went backwards in the breeze, lift would diminish...adding the ballast made better progress of course...but really the ballast needs to be easily adjusted to suit conditions.

Plenty of sites to glide here in the Islands, Fox Bay is not far from my parents farm...same Island. Google earth 'Port Stanley' and 'Sappers Hill' ...I was on the western slope of this.

Rob
So does your newest design have an airfoil in it's wing, or is it just a "flat" wing? I highly recommend using a hot-wire system and cutting an airfoil with that. Airfoils just work better and seem to handle ballast better than a flat wing.

Bird designs, especially the albatross, are also kinda tricky due to the long, narrow wings and the fact that they have a really small tail. But if you plan to give it a go good luck !
Mr. Combat Certain is offline Find More Posts by Mr. Combat Certain
Reply With Quote
Old Mar 21, 2011, 03:07 PM
Entropy is happening!
Jim.Thompson's Avatar
Australia, NSW, Bellingen
Joined Aug 2008
6,787 Posts
Scale Albatross

Quote:
Originally Posted by robwilkinson View Post
.................................................. ........................ My aim is to build my own design based on a Bird we have here, the Black Browed Albatross, a stunning bird and a great topic for a glider design..

.................................................. .................................Rob
Rob,

One my more enduring memories of sailing in the roaring forties in my youth is the sight of Albatross dynamic soaring in the most severe weather imaginable. These were mainly Wanderers I think, but we would occaisionally see Black Browed and other species. Fantastic!
There are scale model Albatross that have been built and flying in several parts of the world. Just do a search here on these forums. Not for beginners though I would suggest. Get some stick time up with a good EPP trainer first and then progress to something more complex.
If I find a post of the scale Albatross (or one of several other birds), I'll post it later.

Jim.
Jim.Thompson is offline Find More Posts by Jim.Thompson
RCG Plus Member
Latest blog entry: Yet another light plank!
Reply With Quote
Old Mar 21, 2011, 03:39 PM
Registered User
Falkland Islands
Joined Dec 2010
64 Posts
Orni freak, yes the wing was cut with hot wire and ply profiles...flat underside with a nice airfoil curve over the top...the uppermost part being about 30 percent..maybe a touch more from the leading edge. The model is not to hand right now...its at home.

I have spotted the earlier posts with links etc...so plenty to check out. Be great to get the Bullet kit I mentioned earlier...but look forwards to designing my own in good time.

Should have done this years back, spent a whole bunch of cash on helis etc...but for a few pounds on glue, foam and tape I can build a whole bunch of gliders...just love the idea of keeping a couple of spare packs for radio and rx and getting some flying in...the exercise is doing me good at the moment...chuck...glide...go get and repeat
robwilkinson is offline Find More Posts by robwilkinson
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Rave Flying Wing Design formulae sloper steve Flying Wings 13 Sep 26, 2011 10:16 AM
Discussion Flying wing design and construction. wjames20 Flying Wings 16 Dec 18, 2010 01:50 PM
Help! flap design help required for swept wing miniphase Flying Wings 87 Nov 07, 2010 12:53 PM
Discussion A mixed Low and High Aspect ratio flying wing glider design for thermalling GreenAce92 Thermal 2 Mar 26, 2009 04:42 PM
Discussion design question for flying wing mig-29ub Flying Wings 3 Aug 23, 2007 10:52 AM