Swing Wing Gliders- Wing hinges (and BIG models too)

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georgegassaway

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I am starting this new thread, in response to the XP-2 Rocket Glider thread:

https://www.rocketryforum.com/showthread.php?t=18078

The issue of Swing Wing pivots came up there.

I want to mention and show what I have done, but not have this info hidden inside of the XP-2 thread for those who might search the forum in the future.

I made lots and lost of Swing-wings in the 1970’s. From 1/4A thru F power. The ones with wingspans of 6 feet or more (one was 10.5 feet), I named Great Danes. I built at least 15 of them. The 15th one was one of the best, built for F Rocket Glide. It used an AVI E11.8 engine plug a B6 to nudge it into F class.

I learned the pitfalls and weaknesses of the original Swing-wings early on, and came up with better ways. Also, my first Great Dane suffered hinge problems due to the mass and deployment momentum of the wings. So I eventually came up with a much more robust (and easy) way to hinge them, using plywood “Pivoters” to take most of the hinge and deployment stress. The pivot pins were simply wood dowels, slid into place in the balsa plates on top and bottom of the pivoters. To keep the holes from being pried open or ovalized from deployment stress, I glued 1/64” or 1/32” plywood squares to reinforce the pivot pin holes. By being able to slide the pivot in and out, I could remove the wings for storage, even swap wings.

By the late 1970’s I moved on to Slide Wings for contest models.

In 1993, I made a B7 powered Rocket Glider for NARAM, due to the light weight of the 13mm B7 casing, compared to an 18mm Estes B4. The B7 thrust was so high that a normal wing would either shred or would need to be built be built too heavy (also draggy for high-speed boosts). So in that case a Swing Wing was the most practical way to use a B7 for a Rocket Glider. That one, I used either .015” or .020” Waferglass (G10) for the pivoters and for the top and bottom plates. , I do not recall which. I do not have any photos of that B7 model, or plans for the model itself. But I did make drawings for the Pivoters, which I have upgraded with color coding so they will make more sense.

In 1992, NARAM-34 had G Rocket Glide. I made a copy of Great Dane 15, including the Pop-Stab dethermalizer used for bringing it down early. I actually used R/C models for our team, that swing-wing was our #3 model (back-up for the back-up). But Mark Hamilton and Tom Beach did build and successfully fly their own copies of that model at NARAM-34 (used on F10 plus two 1/2A motors to nudge into G class.

Photo 1 - 1/16" Plywood Pivoters as used by 6 foot+ Span Great Dane models

Photo 2 - Waferglass pivoter drawings, parts as used for a B7 powered model.

Photo 3 - More B7 model Pivoter drawings, showing boost and glide configurations.

Photo 4 - Great Dane 1, in 1972. I am on the right.

Photo 5 - Myself holding the 1992 Great Dane model, which in 2007 was modified for rudder-only R/C (something I had wanted to do since the 1970’s).

More to come.

- George Gassaway

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stickershock23

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Great stuff George,

I gotta talk to you about a project idea I have. This will come in WAY handy
 

El Cheapo

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Great stuff George,

I gotta talk to you about a project idea I have. This will come in WAY handy
Ohhhh, I've been made privy to this iron in the fire. All I can say is I would love to see this as its gonna be COOL!!!
 

georgegassaway

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More photos

Photo 1 - A Great Dane model from the 1970’s. Not sure of the number. 6.5” span. Used a “K” type tail.

Photo 2 - Myself in 1992 with the model built for NARAM-34, for its first test flight. That one was a clone of the highly successful Great Dane 15 model built in 1976

Photo 3 - Same model in 1992 after it landed. It used a “Pop-Stab” Dethermalizer, to bring the model down early (and safely),

Photo - 4 - Same 1992 model in photos taken in 2007. Overall view with one wing in boost mode and one wing deployed

Photo 5 - Pivot pins removed , allowing wings to be removed. Good view of the 1/16” plywood pivoters glued to wing bottoms, and the thin plywood reinforcing squares around the pivot pin holes

- George Gassaway

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georgegassaway

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Last photos

Photo 1 - View of the bottom of the model in boost mode with wings LOCKED closed for boost. Music wire hooks epoxied to the wings. A music wire pull-pin along the fuselage, with an orange cord attached to it. A VERY strong rubber band up front was set to yank the orange cord to pull the pin out, to unlock the wings. A burn-thread was rigged to hold the rubber band back, to leave the pin in place, until the ejection burned the thread, letting the rubber band yank the locking pin out. I found this was a necessity for very large swing wings.

Photo 2 - Another overall view, wings removed. In this you can see most of the side view of the fuselage. Also, I found the hard way to use a VERY loose launch lug. When I used say a 1/4” lug on a 1/4” rod, the model would bind on the rod if there was any wind. So, I started using 3/8”, even BT-5 (13mm) tubing for the launch lug, off a 1/4” rod.

Photo 3 - Boost at NARAM in 2007, D12-0 to D12-3

Photo 4 - Glide at NARAM in 2007

Photo 5 - same photo as earlier, the 1992 model with myself, converted to rudder-only R/C

- George Gassaway

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sandman

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I made a swing wing glider a very very long time ago. When the motor ejected and the wings swung out it did a 360 degree loop. Way cool...yah, I meant to do that.:rolleyes:

George does yours loop when the wings come out?

Mine looped so well that when the model went into a pine tree during glide the wings folded back as it went through the tree then opened back up as it exited. It did another loop as it left the tree and continued the glide.

You'd think I could duplicate that model...:mad:
 

Zack Lau

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Great posts! Wish we had a field around here big enough to take advantage of huge gliders. I've been busy learning dethermalizer technology as a way to fly gliders would otherwise leave our tiny New England flying fields.
 

BABAR

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George
Appreciate all the pioneering you have and continue to do.
Have you ever done or seen a BIPLANE swing wing glider?
I am thinking of a square cross section rocket body to reduce drag, one wing pair on top and one bottom.
Obvious issues (at least ones I recognize!)

How far apart must wings be (space between lower surface of upper wing and upper surface lower wing) to prevent interference with each other?

Would be easiest to do this with no dihedral. How do you get stability?

Thanks,

Tom
 

BABAR

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George
Appreciate all the pioneering you have and continue to do.
Have you ever done or seen a BIPLANE swing wing glider?
I am thinking of a square cross section rocket body to reduce drag, one wing pair on top and one bottom.
Obvious issues (at least ones I recognize!)

How far apart must wings be (space between lower surface of upper wing and upper surface lower wing) to prevent interference with each other?

Would be easiest to do this with no dihedral. How do you get stability?

Thanks,

Tom
 

Sooner Boomer

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It would be *easiest* to build with no dihedral, but would not be too terribly hard to build *with* dihedral. The main wing pivot box is where the dihedral would be built in. The wings are folded straight back from there. You could make it really complicated by having a pivoting box that was at a right angle to the body during boost, but snapped to dihedral when released. How far from easy do you want to go?
 

Crawf56

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George, are there any plans to your swing wing rocket gliders?

[Note: I am an engineer, with access to a scanner. I can make .PDF's.]
 

Maxout

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Switchblade S is about 16". Switchblade XP is 20", but that's not relevant since I've chosen to discontinue that airframe. I just am not happy with its performance and I've got better designs now. I'll be replacing it eventually though, so fear not, there will again be a swing wing R/C glider, and it will be pretty wild.

The S, on the other hand, performs great and I've gotten very positive feedback. See for yourself:
[video=youtube;KzGHnP9iCpo]https://www.youtube.com/watch?v=KzGHnP9iCpo[/video]
 

Crawf56

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The J&H Switchblade XL is on my build list this year (I have a kit). It requires micro RC gear.

Frank at Dynasoar Rocketry and I had an email conversation the other day, about D-size engines vs E-size engines for rocket gliders. I think Frank has found a "sweet spot" in the design of his models.

While micro servos and micro receivers are available, they are more expensive and difficult to work with than "mini" components (which are used on foam RC model planes). I would like to see an E-motor Swing Wing rocket glider designed around an E-motor, and set for 50 grams of RC components.
 

Maxout

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While micro servos and micro receivers are available, they are more expensive and difficult to work with than "mini" components (which are used on foam RC model planes). I would like to see an E-motor Swing Wing rocket glider designed around an E-motor, and set for 50 grams of RC components.
That's going to require something with a pre-formed airfoil. $$$

Honestly I'd like to release such a thing someday, but it'll be at least a $150 kit.

I've got a couple C rocket gliders with 3-4 g servos. Cheap and easy to buy, easy to install, etc. More importantly, cheap to operate. The second you go above 18mm single use motors, you're looking at double the price per button press. My one complaint with my fixed wing C rocket gliders so far is the launch is really wild. You better have that thing dialed in our you're in trouble. Mind you, I've yet to crash one, but I've got a fair bit of experience flying fast R/C models.

I do plan to release a fixed wing C rocket glider in the 24-25" span range at some point and it should be reasonably docile, but time will tell there. Before that, though, I'm going to crank out another umx swing wing to fill the void left by the Switchblade XP. Hopefully I can run a test launch of the free flight version in a few days; that'll set the stage for what the R/C version will look like.
 

Maxout

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Whelp, a maiden flight has happened. I have a few tweaks to make, and then we're ready for B motors.

[video=youtube;KXotvpkVASk]https://www.youtube.com/watch?v=KXotvpkVASk&lc=z23nwpwzsyjcuzmhv04t1aokg4k rk30gqox4fxkg55tgrk0h00410[/video]
 

James Duffy

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Very cool. You're going to take all of my PayPal money, aren't you?

James
 

Maxout

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The Fliplock A development program has successfully concluded. I'm very pleased with how it turned out, and it's definitely unlike any other swing wing ever.

Here's the build video:

[video=youtube;B1vOoLpH8MI]https://www.youtube.com/watch?v=B1vOoLpH8MI[/video]



Here's the product link: https://jhaerospace.com/product/fliplock-a-rocket-glider/
 
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