Ring Glider attempt

[Alan R]

For some reason I've always been fascinated with O-wing (ring) gliders. I started on another attempt. When researching I came across a video that showed you could do a binocular ring glider and it would fly just as good or better than the original.
Hey, that would solve balance / stability issues I experienced last time. (embarassing, but I learned a lot since then) But making it heavy enough for a rocket .. will it fly? or rather glide? I can make it fly up, but how will it come down?

 

[Alan R]

A fellow club member was giving away 4" tube scraps, and I was thinking, time to get back to that ring glider. I'll take 2.
Researching this again I found several experiments that pointed to a 3:5 ratio for the ring sizes as having better flight times.
Here's what I've got now. I rolled a BT20 tube about a foot long. Cut one of the rings in half for the large ring. I had some leftover 2.6" tube i cut for the small end, pretty close to the 3:5 ratio I wanted.

Then I got stuck on how to attach the rings to the BT.. very minimal glue area. Heavy fillets? Some other method?

When I started thinking about it, I was DUH.. 3D print. Here's what I've got now.

 

[Alan R]

I was thinking this would be cool to do as a rocket glider (booster engine, no ejection).

It would just need balance. So lots of weight on the front to balance an empty motor.

CG after burn should be just slightly forward of center.

I was hoping this would work on a B6 motor. But its really heavy. Best I can calculate, it needs about 30grams in the nose for that, making the whole thing over 100g.
19 - B6
4 - body
36 - aft rings
15 - fore rings
13 - empty casing in front
17 - trim weight (pennies)

I'll go throw it around tomorrow and see if it actually glides. Otherwise I need to re-think this project again.

OR says it will fly nicely, worst case ... I put a chute in it HA

Ideas guys? Here's mine:
1. rear ejection of motor ... but would still be really heavy to glide
2. re-fabricate.. just make one side of it a glider on a balsa stick, pop-pod style.
3. ?

 

[Jeff Lassahn]

Are you going for best glide performance or for coolness? Best glide is going to be the pop pod. Coolness might argue for some kind of variable geometry thing -- can the small rings launch at the rear and move forward at apogee?

 

[Alan R]

I'm just hoping for ANY glide performance

But I'm thinking it's going to be way too heavy for that

 

[BABAR]

You may find this from @Rktman helpful

https://www.rocketryforum.com/threads/best-method-to-bend-balsa.139470/

 

[Alan R]

You may find this from @Rktman helpful

I dont have any spare balsa laying around. at least nothing big enough to bend rings.

 

[Alan R]

welp, just as I feared... its way too heavy, meaning ... not enough lift from the wings.
I think my next attempt will be to re-configure it as a pop-pod.
One side will be a glider and one side will be matching set of rings on the BT.

and those rings come down hard without a forward weight.

 

[BABAR]

What’s your experience so far with rocket gliders? All model rocket gliders require some sort of shift to transition from vertical rocket flight to horizontal glider flight.

As you know, by competition rules rocket gliders retain their motors for the whole flight. Outside competition you can do anything you want as long as it is safe, but looks like you are wanting to keep the model as one piece with motor, which presents some unique challenges, @burkefj does remote control, I am guessing that the rocket is minimally stable on boost (but is to some extent “flown” so has some control), and then throws a lot of elevator in at apogee (added challenge is that the propellant tail weight is actually burned up during ascent, so the rocket is even MORE nose heavy at apogee, making more control necessary.) most NON-remote control rocket gliders has some dramatic “shape shift” at transition, usually slide a lifting surface (wing) forward to bring the CG and CP into optimal glider alignment (as opposed to boost where CP better be behind CG.)

It’ll be interesting to see how you pull this off. Boost gliders that dump the motor (as well as sometime the tubing, nose cone, launch lug etc), are much more efficient gliders, biggest downside is if you use a re-usable pop pod you need to track it as well as your glider. If you simply eject a black power paper and clay motor casing, the need for recovering it varies by opinion and flying field (it’s biodegrade-able and an 18mm casing isn’t going to hurt anyone, but it may mess up equipment in sod farms, so in some cases casing recovery is always courteous and sometime mandatory.)

 

[Alan R]

What’s your experience so far with rocket gliders?

I built several boost gliders when I was 13 (hawk, OT, etc).. And several non-rocket gliders since. So I know how to build them.

I was originally hoping for a design that would work as a rocket glider (engine intact). But this just doesnt have enough 'wing' to generate the lift needed for the weight.

I think i'll move to pop-pod style. Put a streamer in the body, and let one side pop off as a glider --- ooooh or I could make both sides glide off, and just streamer the bt.

Also thinking now that if I make them pop-gliders they will have a balsa spar, I can use that for additional glue surface which means I could go back to the paper tubes and have much lighter weight.

I still want to try 3D printed hoops though, but I have to play with that design to work with a single spar instead of the whole body tube insert.

 

[BABAR]

You probably already have this, but just in case

https://barc775.files.wordpress.com/2015/05/ring-hawk-plans-002.pdf

 

[Alan R]

You probably already have this, but just in case

Oh I've never seen that. Interesting. Thank you.

 

[GlenP]

One option to reduce the weight, you could make the rings like those toy hand tossed ring gliders, or the Estes parasite ring glider, Double Ringer. You just have a thinner solid plastic frame structure for a lip, maybe with a slot or lip edge on it, then you wrap a thin plastic sheet around it. Not exactly sure what material they use in this kit. You could even use cardstock coated with a thin layer of white glue. Or cut sheet from a plastic soda bottle?

https://estesrockets.com/product/007279-double-ringer/
I don't remember the name of the hand-toss toys, they seem to work better when you spin them, but still glide pretty well with their slightly weighted lip at the front.

You can use some kind of rear-eject through tube, like the Astron SkyDart or the Fake Wulf, so that you have a nose weight for rocket stability during boost, but then eject that nose weight portion along with the engine so you have a properly balanced and trimmed glider.

https://archive.rocketreviews.com/reviews/all/rokit_fake_wulf.shtml

 

[Alan R]

One option to reduce the weight, you could make the rings like those toy hand tossed ring gliders, or the Estes parasite ring glider, Double Ringer.

I'm thinking of materials I have on hand... some BT 101 (4" x 1.75") OR .. 3D print new rings. Not sure the weight of 3d rings would matter as much if I'm only printing the rings, and not the big lug that fits the BT. Problem with 3D print is attaching, so I need to design that to fit a spar.
Not sure how much stress the body tube slices can handle though.

 

[GlenP]

maybe print a couple of smaller sized "lugs" on the rings like that can fit over a small diameter dowel, like 1/8", and attach dowels on the body tube that fit into those receptacles? (see how the Double Ringer rings are attached, they are designed to fly off, but you can use a similar attachment to glue them in place)

You can always reinforce the body tube from the inside by using an internal coupler at those attach points. That also can create a weak point, or stress concentration, at the end of the internal coupler, so make it long enough.

 

[Alan R]

maybe print a couple of smaller sized "lugs" on the rings like that can fit over a small diameter dowel, like 1/8", and attach dowels on the body tube that fit into those receptacles?

kind of what i was thinking.. just build the whole "pod" as part of the ring.
just integrate these right into the ring: Holverson Hooks

 

[Rktman]

welp, just as I feared... its way too heavy, meaning ... not enough lift from the wings.
I think my next attempt will be to re-configure it as a pop-pod.
One side will be a glider and one side will be matching set of rings on the BT.

and those rings come down hard without a forward weight.

View attachment 433564

Consider 1/64" ply for your rings. Extremely easy to form and lighter than a body tube or 3D printed ring of the same diameter. Available online from Amazon or model aircraft outlets if you don't already have some. Depending on the length of your ply ring, it may need bracing on the inside. A very narrow 3D printed ring similar to what the Estes double ringer has could suffice if glued to the forward end of your ring.

 

[Alan R]

New fore ring.

 

[Nytrunner]

Not exactly sure what material they use in this kit.

Its cardstock. Real fun kit

 

[BABAR]

What’s your experience so far with rocket gliders? All model rocket gliders require some sort of shift to transition from vertical rocket flight to horizontal glider flight.

As you know, by competition rules rocket gliders retain their motors for the whole flight. Outside competition you can do anything you want as long as it is safe, but looks like you are wanting to keep the model as one piece with motor, which presents some unique challenges, @burkefj does remote control, I am guessing that the rocket is minimally stable on boost (but is to some extent “flown” so has some control), and then throws a lot of elevator in at apogee (added challenge is that the propellant tail weight is actually burned up during ascent, so the rocket is even MORE nose heavy at apogee, making more control necessary.) most NON-remote control rocket gliders has some dramatic “shape shift” at transition, usually slide a lifting surface (wing) forward to bring the CG and CP into optimal glider alignment (as opposed to boost where CP better be behind CG.)

It’ll be interesting to see how you pull this off with your design,

 

[Alan R]

new aft ring. I made some guides for the balsa spar in it.
still feels pretty darn heavy dammit. But I'll give it a real test tomorrow outside.

 

[BABAR]

Another interesting ring glider.

This one depends on rotation imparted by airfoiled fin “spokes” on boost.

https://www.spacemodeling.org/jimz/eirp_56.htm
I haven’t successfully built one, maybe someone on the forum reading this has and can chime in.

 

[BABAR]

new aft ring. I made some guides for the balsa spar in it.
still feels pretty darn heavy dammit. But I'll give it a real test tomorrow outside.

View attachment 433664 View attachment 433665

“heavy” gliders can still be a lot of fun, especially if you don’t plan on competing, you fly in a small field, and/or you don’t have children, grandchildren, or other minions to retrieve them! As long as they come down safely and don’t break, and aren’t too much of a PITB to prep, they add some nice variety to both private and club launches,

 

[Alan R]

“heavy” gliders can still be a lot of fun,

so long as there is at least some semblance of a "glide ratio" instead of a nosedive. which is what keeps happening here.

 

[BABAR]

so long as there is at least some semblance of a "glide ratio" instead of a nosedive. which is what keeps happening here.

Unless you have some major shift of either CG back or CP forward, or you can add a lot of up elevator, I think any stable rocket is going to prang (aka St.Louis Arch) on descent.

 

[Rktman]

“heavy” gliders can still be a lot of fun, especially if you don’t plan on competing, you fly in a small field, and/or you don’t have children, grandchildren, or other minions to retrieve them! As long as they come down safely and don’t break, and aren’t too much of a PITB to prep, they add some nice variety to both private and club launches,

Totally agree. Except I'd welcome some little minions to run retrieval duty for me.

 

[BABAR]

so long as there is at least some semblance of a "glide ratio" instead of a nosedive. which is what keeps happening here.

Yeah, you at least want to “fall with style”


BTW, I caught a line here I missed in the movie, where Woody calls Buzz “Mr. Light Beer.”

 

[Charles_McG]

Another interesting ring glider.

This one depends on rotation imparted by airfoiled fin “spokes” on boost.

https://www.spacemodeling.org/jimz/eirp_56.htm
I haven’t successfully built one, maybe someone on the forum reading this has and can chime in.

I’ve built both the Stovepipe and the Ringhawk. The Stovepipe by itself hand-tosses very nicely. I was never able to get it to separate from the booster cleanly. I even build an elastic loaded booster like the Ringhawk to throw the Stovepipe over the booster nose.
The Ringhawk fell gently to earth for me - I never got any forward motion out of it.
My experience with the ‘Zylo’ type gliders is that if you can throw them with very little angle of attack and a spin, they will lock onto a glide path and go far. But too far off angle, and the just flop. And a rocket booster is unlikely to release them at the right angle. Also, they fly -straight-, no corrective action. If the glide path is a dive, it won’t increase, nor decrease the angle to the ground.

 

[Rktman]

so long as there is at least some semblance of a "glide ratio" instead of a nosedive. which is what keeps happening here.

I've built the Ringhawk and it glides remarkably well...IF you get the CG exactly where it needs to be. Since your ring glider is nose-heavy, try adding clay ballast to the tail end a little at a time to counterbalance things and get the CG where it wants to be.

Also shedding weight would really improve things. GlenP had some great ideas to reduce weight. That in conjunction with larger rings would also provide more lift per gram. Of course that may mean having to reconsider limiting yourself to materials on hand to get things to work.

 

[BABAR]

I’ve built both the Stovepipe and the Ringhawk. The Stovepipe by itself hand-tosses very nicely. I was never able to get it to separate from the booster cleanly. I even build an elastic loaded booster like the Ringhawk to throw the Stovepipe over the booster nose.
The Ringhawk fell gently to earth for me - I never got any forward motion out of it.
My experience with the ‘Zylo’ type gliders is that if you can throw them with very little angle of attack and a spin, they will lock onto a glide path and go far. But too far off angle, and the just flop. And a rocket booster is unlikely to release them at the right angle. Also, they fly -straight-, no corrective action. If the glide path is a dive, it won’t increase, nor decrease the angle to the ground.

Interesting


The “Ultra” looks pretty much like the”StovePipe” rocket, short, nose weighted, maybe a bit flexible but I think in flight probably pretty stiff. And seems like it HAS to be thrown with a strong longitudinal rotation (sort of like a football). I buy the concept that this is really Gliding”

The “Air Rider” however from the video looks like it can be flung at any angle, although looks like flies better with a spin. I think these “air riders” look more like the new Estes Neon Tiger and Double Ringer. I am not as convinced that these (on the above video) glide so much as fly like a tennis ball with a cloth tail on the back.

Only review I have found here was underwhelming
https://www.rocketryforum.com/threads/estes-solo-double-ringer.154529/
This video of Estes solo was not very impressive, to say the least