Aether Joined-Wing Concept Glider

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Another off-the-wall, offbeat design inspired by the Deltoid and joined-wing planes in general. Why “Aether”? Well, its structure is very minimalist and most of it is empty space.

It’s a swept-wing design with a joined “stab” section that also provides support for the high aspect ratio wings.

I also decided to try experimenting with having the canard elevator flaps on its leading edge rather than its trailing edge.

Glider illustration.png

Projected glider length = 27”, 31” when motor pod is included. It’s strictly a sport model intended for small-field flying, which is why it’s more mid- to largish in size (which also conveniently makes it easier to find in the multi-acre farm fields our NC clubs use).
 
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I made a small 50% mock-up that glided surprisingly well. It’s fragile though and prone to breaking, so I couldn’t put much force behind the tosses. I should have used something sturdier than scrap 1/32” balsa that was lying around, but I’m satisfied that it’s proof of concept, so I’ll move ahead with a full-scale build.

50 percent prototype.jpg
 
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The main fuselage of the full-size version is a 3/8” wide x 1/8” thick x 20.75” long piece of hard balsa. Of course strips of balsa have an annoying tendency to warp as soon as you cut them out of the parent sheet. I straightened it as best I could with heat and moisture, then to ensure it stayed as straight as possible as well as reinforce it, I decided to use a “T-bar” format. I cut a 3/8” wide x 1/16” thick strip of balsa and glued it to the bottom edge.

To reduce weight at the aft end, the last 8.5” of the fuse was reduced down to 1/8” at the aft end.

T-bar-1.JPG


The trailing edge of the canard was then attached to the fuselage. The elevator flaps are the only movable parts and are a bit fiddly to deal with, so they’ll go on later.

fuse-canard.jpg
 
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cls

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That's a cool planform. Very creative. I hope it works as well under boost as in gliding.
 
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The wing and stab were attached to form the joined/blended-wing. I sanded in a modest airfoil into the 3/32” wing, bringing the trailing edge down to 1/16” thickness to match the stab, which is 1/16” balsa.

wing-L.JPG

IMG_9643.JPG


I had originally planned to attach each wing to the sides of the fuselage and give each wing 1.25” of dihedral, but decided that the wings would stand a better chance of launch survival if I glued them together to form a single unit and mount that to the fuselage bottom. Since swept wings exhibit an inherent dihedral effect by nature, I decided to forgo raising the wingtips in favor of strength.

wings.JPG

The assembly was then glued to the fuselage (forgot to snap a shot of that).
 
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Canard flaps attached and hinged with Blenderm.
Since they’re actually reversed so that they’re in front, they’ll flip positive to channel airflow downward.

IMG_9656.JPG


Cobbled together a foam and 1/64” ply jig to limit the angle of the flaps while trimming. Simply sliding it forward or backward will allow the angle to increase/decrease. Once the right positive angle is found, I’ll figure out a way to freeze its movement, probably a bent piano wire limiter or a balsa one.

IMG_9647.JPG

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Rudder attached. I decided to reduce aft-end weight by having just a single bottom-mounted rudder instead of dual rudders on each wing.

IMG_9672.JPG


Completed glider waiting for a low-wind day trimming opportunity.

IMG_9678.JPG
 
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Took advantage of a single digit wind day to do some trimming tosses. Despite the less than comfortable 35°F temp, mornings are always best before the day’s heat begins to generate winds or thermals.

Anyway, I had to add 3.64 grams of aft ballast to get a nice flat glide. The CG is unusually far back for what I’ve come to regard as basically a canard. It surprisingly falls almost 3” back from the forward apex of the main wing. Seems it could benefit from larger canard flaps. Regardless, I’m stoked that the design actually works and glides fairly well for something so large. I’ll be even happier if I can get it launched without shredding on the way up.
 
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waltr

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Interesting design and great news about trimming and glide testing.

Was it stable side to side without the dihedral?
 
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Got around to finalizing the motor pod design that’s been floating around in my head. The whole reason for a front-mounted elevator flap (besides curiosity about feasibility) was that I reasoned it would be easier to devise a hold-down method than for a rear-flap canard design.

Bruce Blackistone’s Valkyrie cleverly used small dowels held down by the motor pod, but I didn’t want that extra weight up front, as canard gliders are notoriously sensitive about front-biased weight.

pop pod detail.jpg


Pylon with flap hold-down and 1/32” ply angle limiter. To make sure it’s securely anchored, there’s a tab in its base that’s glued into a slot cut into the canard wing. I suppose I could’ve gone with a bent-wire limiter, but the rear fixed part of the canard wing is pretty thin and fragile, and I figured it would be harder and riskier to bend the wire to adjust it than just sanding the ply limiter (or shimming it with small balsa slivers to reduce the angle).

IMG_9679.JPG


Pretty simple. But then, simple is always better than complicated – there’s far less that could go wrong.

View attachment flap.mp4
 
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Attached pylon to pop pod with centering jigs to make sure everything is straight and square.

IMG_9692.JPG


Had a small window of warmish temps (low-50s) so I took a chance and misted the glider with some fluorescent rattle can spray to ensure I can find it once it touches down. Fortunately fluorescents are thin with a dull finish, so they dry really quickly, unlike gloss enamels or lacquers. No drips or runs, and since fluorescent sprays are mostly carrier fluid/solvent, the amount of weight they add to a glider is negligible.

IMG_9716.JPG


I decided to go with a shorter rear-eject motor pod since the canard flaps are locked in a neutral position and there’s no incidence on the glider’s flying surfaces to affect a vertical launch.

IMG_9702.JPG
 
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UPDATE

Monday, 12/26/22 wind: 5 – 6mph, 40°F

Airborne!

Bit late in posting this, but I had a single-digit low-wind day opportunity and took it to test launch the Aether. As hoped, it had the ideal perfectly vertical launch on a B4-2. Even better, it didn’t shred on the way up. There was a nail-biting moment when it arced over during the delay and I thought it might re-kit itself before it transitioned. Glad the B4 only had a 2-second delay.

As soon as the pod kicked, it transitioned immediately into the most unexpectedly gratifying flat glide. Even more surprising was that it actually glided better without the aft clay ballast (which I had removed when I added color to the glider and then forgot to reattach). A case in point that even careful or meticulous trimming doesn’t guarantee that a glider will react the same way once it’s launched and subject to the stresses of being kicked forward hard by the ejection charge, the effect of crosswinds, temperature, air density, and all the other variables at altitudes higher than ground level. You never know until you do a test flight…or several…and adjust things to get some kind of consistency.

Overall it was a good flight day and I’m more than happy with the success of having an experimental design like the Aether perform successfully, and better than I had expected.

The one thing that kept it from being an ideal day was that my GoPro messed up and only captured 1 frame. I haven’t figured out how that could even remotely be possible. Anyway, I’ll try again tomorrow as it’s forecast to be another low-wind day.

WTH? 1 frame video?
View attachment GH010027.MP4
 
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UPDATE

Tuesday, 12/27/22 wind: 3 – 6mph, 37°F

Got lucky and this time I got some complete GoPro footage. It’s a bit grainy and pixelated though since I had to digitally zoom it way in to make the glider visible. Not bad – a 31 second flight on a B4-2 for a 28.9 gram glider. Just right for a small-field sport flier that I won’t have to spend a lot of time chasing down on these geriatric old legs.

There was a family nearby with 4 or 5 kids and I think I confused the heck out of them after they launched a rocket just before I did and was expecting that to drop down on them on a chute, but unexpectedly got a strange gliding thing instead.

 
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Thanks for visiting the build thread and your for your feedback gents.

If anyone's interested in building the Aether I can post the templates here.

I'd be real interested in anyone's improvements or mods to the design, make it a sort of “open source” project where you could post and share your changes and ideas in this thread.
 
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Aether templates.
If you build, I'd love to see your pics, flight report, or any improvements or mods you made to make it better or more unique. Cheers.

EDIT: If it's not already obvious, the main wing/stab and canard are mounted under the fuselage. No dihedral is necessary. You can use elastic thread, cord, or the elastic of your choice for the canard flap. I used tan contest rubber only because I happen to have a ton of it. You really don't need a lot of pull; only just enough to get the flap moving. Windspeed will do the rest.

As far as the flap stop, you can use whatever method you choose. I used 1/32" ply because I found it the easiest. The template is for an elevator angle I found works for me, so you'll have to adjust yours after trimming). If piano wire or balsa or some other flap stop method works for you, go for it. Hopefully the build thread provides enough info as to how things go together; there aren't a lot of pieces and it's really a Skill Level 2 project. Of course, if anything is unclear, feel free to ask.

One final note: everything got two coats of thinned dope to both strengthen and humidity-proof the glider. If you're considering using a C motor, I'd do the same.
 

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Cape Byron

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Thanks for visiting the build thread and your for your feedback gents.

If anyone's interested in building the Aether I can post the templates here.

I'd be real interested in anyone's improvements or mods to the design, make it a sort of “open source” project where you could post and share your changes and ideas in this thread.

Extremely generous of you. I think an open source thread has some real potential. There are many of us with designs to share.

I fancy making a parasite glider version... 🤔
 
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Extremely generous of you. I think an open source thread has some real potential. There are many of us with designs to share.

I fancy making a parasite glider version... 🤔
Very cool. Would actually simplify things as far as retention of the canard flap in a neutral position is concerned.
 

Aeronerd

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Very cool design. I downloaded the plans and want to do a version with a body tube. i think that would be neat to do with the flaps controlled like the old Centuri Acro Bat. The front of the BT would move forward just a tiny bit enough to release the flaps.
 
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I like that idea. Being that it's a hollow tube, it might even end up being a little bit lighter, especially if you can jettison the motor tube on a chute or streamer.
 
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Received a DM from someone having problems reading the pdf template files. Since I'm nowhere near an Acrobat tech or any good at solving pdf issues, here are the same files in jpg format. Hope everyone is having a great New Year's holiday.

wing-stab-rudder templates.jpg




pop pod_pylon templates.jpg




construction details.jpg
 
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