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Old Sep 25, 2011, 08:36 PM
free bird
Mickey D's Avatar
South Africa, GP, Johannesburg
Joined Aug 2011
169 Posts
well thats why we fly indoors, among other reasons!
she looks small enough to fly in the living room. BTW real cute too!

Mike
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Old Sep 25, 2011, 11:47 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,405 Posts
while it will fly across the living room, its not in a suitable condition to be in a video at the moment

getting ready to go to my brothers wedding things are a mess. there might be a good place down near the wedding though.
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Old Sep 26, 2011, 05:10 PM
free bird
Mickey D's Avatar
South Africa, GP, Johannesburg
Joined Aug 2011
169 Posts
Seriously take it with you it's a once in a lifetime if there is a indoor dinner thingy you could catch some major indoor thermals, im sure your bro won't mind as long as it doesn't land in the mother in laws soop

Well I tried to convert a flying wing into a hang glider, but no matter what I did it fliped upside down and continued to fly inverted, even with reflexed trailing edge. I tried streamers but to no avail, same problem I can't seem to get any flying wing or hang glider to work so I might stick to the conventional "tailed" craft that never lets me down, at least for now.
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Old Sep 27, 2011, 08:56 PM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,622 Posts
Well I tried to convert a flying wing into a hang glider, but no matter what I did it fliped upside down and continued to fly inverted, even with reflexed trailing edge. I tried streamers but to no avail, same problem I can't seem to get any flying wing or hang glider to work so I might stick to the conventional "tailed" craft that never lets me down, at least for now.[/QUOTE]


Mastermike: The world of flying wings is larger than it may appear.

A simple Delta wing is a flying wing, but is different than the swept-aft, higher aspect ratio type such as Derk's.
Trailing edge reflex works fine on the Delta, but may not be of much benefit on the swept-back wing. One of the ways of understanding this type of wing is to compare it to a tailed design. The center section, or root, has a positive angle of incidence, just like the wing of your tailed design.
The outboard area of the swept flying wing is like the tail of a regular plane, it has a less positive angle of incidence than the wing. That's because you twisted the wings a few degrees, putting "washout" in them. I refer to this as "planform reflex", as opposed to airfoil section reflex. It is very effective for providing a nose up pitching moment. Not enough twist and too much camber and your flying wing will want to "tuck" and fly inverted, as you reported on your experience. Remember that camber is "anti-reflex", so keep the amount of camber low, and keep it well forward. We like camber because it increases lift, but it's nose-down pitching moment must be countered with airfoil reflex or planform reflex. So if you use too much, you'll need so much twist or reflex to balance it out that the glider will be "doggy", it'll have a poor glide.
The vertical fin of the tailed design is replaced by the sweep-back in the planform. It's surprisingly effective, more so than one might think at first glance. Also, the sweep will have a dihedral effect. In fact, not only will you probably not have to add any dihedral at all, you can actually get away with a small bit of anhedral, depending of course on the amount of sweep. I never use more than 20 degrees of sweep (as measured at the leading edge) and prefer anywhere from as little as 10 to usually right about 15.

Your enemies are too much taper in the planform, and excessive dihedral. Put too much of these in and you've got a "spin gypsy".

So why a flying wing anyhow? The answer : Design Economy.

There ain't nuthin' there that don't absolutely have to be there: Two wings, a left and a right, and maybe some nose weight, that's it. I don't know how many times I've been somewhere and I got to do some flying because I had a sharp knife in my pocket (I prefer the dollar store ones with "snap-off" blades.) A piece of scrap foam or cardboard, a dime or penny for weight, and goodbye boredom! No glue or tape, just cut out a simple 'chevron', cut a slit to put the weight in, twist the wings or add reflex to the tips, and voila! A model airplane in minutes. The local kids will think you're a god.

P.S. : Instead of reflexing the tip area, try drooping the trailing edge in the root area. Does the same thing but will slow the glider down better. Best with constant-chord planforms. For more experimental fun, make the root chord narrower than the tip chord. I call this the "canard flying wing". Don't stop trying new ideas, that's where the fun is.
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Old Sep 27, 2011, 09:49 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
2,290 Posts
If you are interested in walkalong flying wings give these a try. Simple to build. I have a couple of additional designs that are stick and tissue builds. I will post them later as they are on a different computer. These are not my designs but are for public use. The green and white one is a little club racer I built. It flys very nicely.

Wayne
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Old Sep 29, 2011, 12:15 AM
free bird
Mickey D's Avatar
South Africa, GP, Johannesburg
Joined Aug 2011
169 Posts
Wow thanks for the advise guys! Itís just that I have been building slow flying living room gliders for years even before I had accesses to the internet and discovered this affect, but the problem was with the turbulent updraft meeting the horizontal stab causing the nose to dive which is why I have been wanting to build a flying wing especially after seeing that video. Another thing I have been experimenting with Is putting the horizontal stab ahead of the wing with some success, but now that you guys have given me a better insight as to what I am doing wrong I will give the flying wing another shot. As dayhead mentioned I think my problem is somewhere between having too much camber and dihedral. the last one I built had the max thickness at 40% no twist and a moderate sweep With reflexed crossection at the tips. well it went in the trash, a bit more knowledge gained I suppose as long as I take note of my mistakes.

Wayne thanks for the plans! but I no longer have a printer so I make use of the drawing board, But if you have any more plans that can be used for a walk along glider please do share with us, it also helps with inspiration! especially the second one (Easy glider plan).

P.S I just noticed on the green and white club racer looks like there is a bit of undercamber on the wing. anyhow, I have been thinking of building a couple similar planes for the local orphan center in benoni it apears to be verry simple and use few materials I have heaps of tissue that I hardly use and it's a great way to get the youth interested in such a hobby after all they are the future hobby suppliers.

sorry for the lack of better words and propper grammer but as long as you understand what I mean!

Mike
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Old Sep 29, 2011, 03:37 PM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,622 Posts
Nice gliders there Windependence. The Aeronautical layout suggests the Genesis sailplane.

"Plank" style flying wings suffered by having the elevator attached to the wing. The Genesis, designed primarily by James Marske, tried to get around this by mounting the elevator remotely from the wing, on top of the fin. It wasn't a stabilizer, the wing itself was pitch stable, it was used as an elevator only.

Walkalongs do suffer from a stabilizer in the back, I guess you could call it a "stab in the back".

An excessively swept flying wing can suffer from the same effect. Plank designs are probably optimal for this type of flying, but the vertical fin requires nose weight. The lighter it is the slower it can go, that you don't have to run fast to keep up with it.

Not too long ago I was flying one similar to Derk's glider outdoors. There was a maybe 2 to 4 mph breeze coming up my steep driveway, and I had a 4 foot square slope in my hands. Didn't have to walk at all, in fact occasionally had to take a couple steps backwards when it "gusted" to 5.

Very enjoyable experience. I think I was getting flights of 2 to 3 minutes, but didn't time them.
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Old Sep 29, 2011, 03:51 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
2,290 Posts
Here are a few more. I think I have about a dozen different designs I collected from various internet sources over the years.

Wayne
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Old Sep 29, 2011, 04:06 PM
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Joined Feb 2011
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Well, got a real nice glider made. Built a pretty nice hot wire cutter built to that let me slice a pretty thin sheet of expanded foam. I didn't go with the swept back wing design, I was going to but after cutting it out and covering it I realized I had forgotten to cut it out that way. I also think I built it too thin because it flexes from its own weight when you pick it up. But you can simply let it go and it glides all the way across the room. Needed only two small squares of tape on the nose to balance. Ill post pictures later when I get the camera out. Thank all of you for all the help and encouragement.
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Old Sep 30, 2011, 01:59 PM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,622 Posts
If the wings sag a bit while you're supporting it in the center, you've probably got it just right.

Model airplanes, in general, are overbuilt. This is good so that we can casually pick them up and carry them around.

Picture the Jolly Green Giant reaching down and picking up a full scale plane. He would almost certainly ruin it. Airplanes are built to withstand FLO, or "flight loads only".

Indoor and walkalongs are probably best built to a similar standard, except for kids, who like running anyhow.
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Old Sep 30, 2011, 02:57 PM
RC BARNSTORMER
rcflyboynj's Avatar
R/C Barnstormers of Hillsdale, KS
Joined Dec 2008
213 Posts
Saw the thread on the main page ant thought this video might be of interest to you guys.

2010 Central Plains E - Fly Free Flight/Stick and Tissue Models (3 min 6 sec)


~Nathan
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Old Oct 01, 2011, 11:15 AM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,622 Posts
Life offers many good experiences, but it's a challenge to have one as satisfying as watching your rubber powered stick'n'tissue airplane circle up and around and then make a nice landing.

Nice video.
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Old Oct 02, 2011, 10:07 AM
Registered User
Joined Feb 2011
59 Posts
Does anyone have plans for a walkalong biplane? I have seen people flying them in videos on this site and youtube but have not been able to find plans for a small glider. Space is limited here for flying but I'm getting addicted to building these things. lol I've got 4 different gliders built now. One wing with a 14 inch wingspan, a smaller swept back wing with a 6 inch wingspan, one dart, and and a small wing that resembles the jet from batman. lol Again thanks for all the help.
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Old Oct 03, 2011, 11:25 AM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,622 Posts
I think a Walkalong type glider made to resemble the Wright 1902 glider would be fun.

I was on a Wright Brothers kick many years ago. I found that pitch stability was best when the wing airfoils were reflexed enough that the glider would fly without the canard. I would then mount the canard with just a smidgeon more incidence than the wing, and ballast to trim it.

Also only a small amount of dihedral was required, and turn trim is GREATLY affected by any tilt in the canard.

I may just revisit this glider, I remember it was challenging but fun.
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Old Oct 03, 2011, 02:26 PM
Registered User
Joined Feb 2011
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That would be something to see! lol Last night I spent some time looking up pics of ww1 biplanes and found bunch of pics of an Albatros DVa. Well I just had to make one so I got out the hot wire and started some new slices of foam. Used black meat tray foam for the fuse and the expanded packing foam for the rest. Glides SO SLOW! I love it. Im going to try to finish it today. Add details like the landing gear and gun. I would love to paint it but dont want to add any more weight than needed. idk We will see how it goes once I get the rest done. If you want to see the site I found its fiddlersgreen.net
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