Scissor wing transport inspired B/G (pic heavy)

[Amsterdam]

Kinda just had an idea and went for it. It glides alright without trim I’m hesitant to adjust the elevator. Isn’t there a rule on elevator angle? No more than 10 degrees?

It has a 24” span, dihedirial is 16 degrees, glider weighs 16 grams. The wings removable, and it flies on mini engines. Probably just the a10

anyways here’s some nudes, will probably only had a stripe or two and paint the booster.

 

[Crawf56]

Bravo! Well done! :wink:

 

[burkefj]

Nice, a swing flop..

 

[Maxout]

That looks awesome! Let's see it fly!

 

[Amsterdam]

Thanks guys!
Should get flown this week along with all my other gliders if i get a calm day
Itll be a cell phone video but my partner will do her best to capture it.

 

[Rktman]

Very cool! Clever wing locking and deployment system that looks very reliable.

 

[Amsterdam]

Very cool! Clever wing locking and deployment system that looks very reliable.

Thanks! Nothings simplier than a toothpick haha, unfortunately I’m having flop deploy issues, the hooks are either too close or my rubbers too weak.

 

[Rktman]

Thanks! Nothings simplier than a toothpick haha, unfortunately I’m having flop deploy issues, the hooks are either too close or my rubbers too weak.

They look like they work fine in your video?

 

[Amsterdam]

They look like they work fine in your video?

They open fine when the gliders not falling, but for one reason or another as the glider falls, the resistance from the air holds one, or both closed for far too long.

 

[Rktman]

They open fine when the gliders not falling, but for one reason or another as the glider falls, the resistance from the air holds one, or both closed for far too long.

Guess the easiest 1st step is to test a shorter/stronger piece of elastic. How about a motor with a shorter or longer delay so that your glider is moving slower when the ejection charge deploys your wings?

 

[BABAR]

VERY nice. Your flop wings may solve my problem with obtaining dihedral on a biplane rocket glider.......
Thanks!

 

[Amsterdam]

Switched to a very short piece of sewing elastic. Just knotted each end to give the hooks something to hold. Has a much stronger response, idk how well these hinges will hold up but it was boiler plate anyways.

 

[Amsterdam]

VERY nice. Your flop wings may solve my problem with obtaining dihedral on a biplane rocket glider.......
Thanks!

The folded end, atleast on this my first attempt at it, is very draggy. The model itself has to be on the razors edge of stability because of that chunky wing and rear engine.

 

[Rktman]

Switched to a very short piece of sewing elastic. Just knotted each end to give the hooks something to hold. Has a much stronger response, idk how well these hinges will hold up but it was boiler plate anyways.

Hope that solves the problem and you have a successful flight.

 

[Amsterdam]

Thank you!

Should I build more flop wings what is the recommend material for live hinges?

I’ve found examples of them done in multiple ways, I’m not a big fan of the nylon mesh/CA hinge,And pinned hinges never lay flat. So I’ve resorted to using self stick labels reinforced with CA, which are prone to tearing.

Open to all kind of opinions

 

[burkefj]

Joshua Finn could give a good answer, I would think live hinges, of mylar, tape, blenderm, monokote would be good but I have not built anything other than hinged surfaces which are similar but not exactly what you are doing.

 

[Rktman]

Thank you!

Should I build more flop wings what is the recommend material for live hinges?

I’ve found examples of them done in multiple ways, I’m not a big fan of the nylon mesh/CA hinge,And pinned hinges never lay flat. So I’ve resorted to using self stick labels reinforced with CA, which are prone to tearing.

Open to all kind of opinions

Agree with burjefj, I've seen all those materials used successfully . Bought some blenderm and self-adhesive mylar tape to use with the flop wing glider I'm building, may go with the mylar since it's really light and tough. I've even resorted to using duct tape on a big glider where I wasn't all that concerned with weight, since it's a really tough fabric mesh and polyethelyne tape. In your case mylar would be my first choice because of it's low weight and strength.

 

[Maxout]

I see I've been called out

I've got a couple of go-to materials for flop wing hinges:
1. Polyspan; this is what is included in my kits. You can attach it using a variety of ahesives. It's basically a plastic tissue paper. Moderately tough and seems to last a long time. Available from faimodelsupply.com; get the medium weight stuff.
2. Coverite; this is a super tough mylar/fiber material that is semiporous so you can get a strong bond. I've had some minor issues getting a good bond with my preferred ahesives, but you can attach it with CA for an extremely strong bond. My earliest flopwings used this material and it has *never* failed. I don't know how much longer it will be available following the demise of Hobbico.
3. Kevlar; yes, that stuff. Attach with epoxy. It'll basically never fail, but it's a pain in the neck to work with. Once in place though, it's the best hinge material on earth and you can vacuum bag it down for a perfect finish. I recommend sub-2 oz Kevlar for this task. Don't get Kevlar tissue since it's not nearly as strong and a little weird to work with. And yes, I have used this on hinges for folding wings. It's on a separate plane of existence. If your task doesn't need it, use an alternative. On the other hand, if you use it, it will not fail you.
4. Monocote; Works well enough, but I usually end up going back and sealing the hinge points with CA to eliminate peeling. This is mainly my lack of skill with iron-on self adhesive coverings.

-Josh

 

[Amsterdam]

Thanks for all the information guys!


Maxout, haha I’m the guy who suggested quetzalcoatlus, quetzal, for the windlance contest. I’m excited to try the mini version. it’s not really the place to say this but it is my thread lol... loving all that you and the rest of the Finns are doing over at J&H. Keep it up!

 

[Maxout]

Thanks for all the information guys!


Maxout, haha I’m the guy who suggested quetzalcoatlus, quetzal, for the windlance contest. I’m excited to try the mini version. it’s not really the place to say this but it is my thread lol... loving all that you and the rest of the Finns are doing over at J&H. Keep it up!

Glad to help. Well, the other guys are the ones who did the helping, but I'll claim some credit because I can.

We definitely enjoy the craziness we do. I think Caleb has the most fun.

 

[Rktman]

Now that I'm building eRocket's Scissor Wing Transport clone, I'm really appreciating how cleverly you engineered both the retention and deployment mechanisms. Much simpler, not as finicky and dependent on exacting alignments, easily fabricated with a hobby knife (no expensive laser cutter required) AND you managed to design in dihedral.

Did you ever get around to launching/flying it? It's seriously inspiring me to build a version based on your design.

 

[Amsterdam]

Did you ever get around to launching/flying it? It's seriously inspiring me to build a version based on your design.

Thank you for appreciating the build,
yes i have launched it numerous times and some were successful,
this was very early in my attempts at "advanced" techniques like hinged wings and I was still quite novice with gliders as well

by the time I got gliding flights the body tube was warped, dented, and crumpled beyond repair.

lessons learned from this were:
#1 : paper body tubes make terrible airframes (especially Bt-5)
#2 : High aspect wings are troublesome to balance and trim
#3 : if your folding wing tip is 1/3rd span build the hinge tear proof, and use a lot of force to unfold it.

If I were to rebuild a rocket of similar or at least inspired design I would:

not use a body tube for at least the back 75% of air frame and reinforce the front 25%
use a wing of larger chord/ smaller aspect ratio
play around with full span-wise breaks and hinges to roll the wing around the airframe for boost.
I believe you could still implement the dihedral hinge with this method too.

I may build my latest day dream and post it here,
Jim walker style hinge combined with span-wise breaks,
I envisioned a spring loaded nosecone held over the folded wing edges for boost.
Rough sketch below:

 

[Rktman]

Thanks for the feedback, really appreciate it!

 

[TheAviator]

play around with full span-wise breaks and hinges to roll the wing around the airframe for boost.

The UK Space Modeling team tried something like that for the S4 Rocket Glider event at the World Championships one year. The span-wise folding seems to work well, but the chord-wise folds always end up more finicky because a small angle shift can result in a large change in trim. Basically, performance was excellent but reliability was lacking.

https://www.nar.org/wp-content/uploads/2014/05/JACOMB-SPECIAL-S4A-Instructions-UK-Oct-10.pdf

 

[Amsterdam]

The UK Space Modeling team tried something like that for the S4 Rocket Glider event at the World Championships one year.

that is AWESOME! its interesting that they don't try to streamline the tip of the rocket, and frustrating that they don't show the wing deployed.

my idea was to use a single span wise break, with a single dihedral joint right at the center thanks the the JW interceptor style hinge.

My idea is to JW hinge the LE half, add a pseudo right triangle shape riser between wing portion and the hinge (bottom of wing is the hypotenuse and adjacent on the span-wise break) the riser causes the LE portion to fan out (turn in?) when folded, creating space for the TE's to fold into a triangle cross section, there should be enough play for them to overlap.

Compare the patent below to my rough sketch in the post above.

 

[shockie]

Way Cool. Unlike the original SWT which had no dihedral and hence no roll stability, this one does. Launch that puppy and post a video or pics.

 

[Amsterdam]

as stated above this model has been destroyed due to the stresses of flight and landing on the body tube.

the OG post is from 4 years ago..