Hey guys here's a cool one!
The Tumble Wing designed by Roy Clough Jr.
This was redesigned from an old plan set scanned from a model airplane magazine in PDF format.
I took a screen shot of the PDF and traced the parts in Sketchup.

Material needed

*-(1) 3mm foam (1 sheet)
*- (1) 1/16" Plywood (12"x6" MidWest http://www.midwestproducts.com/catalog_ ... &sa2_id=27 )
*- (2) 1/8" Carbon Rod
*- (1) Brass tube 1/8" I.D.(Used as coupling for carbon rods)
*- (8) Small Washers 1/8" I.D. Plastic would work best

1/16" Fishtail Chipper bit (PhlatBit Kit http://www.phlatboyz.com/phlatstore/#ec ... uct=297620 )

Most of these items you can find around the shop
I test flew this and it glides great!
Enjoy!

Check out the recorded version of the LIVE show here:
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Dennis, it isn't a silly question, lols. if you look at the drawing, the model was made for control line....back in the old days, fellas got ther kicks by hooking up two strings to control the elevator, wile they go round and around in circles, lols. mark can always razor knife a split for rudder control, and forget the strings. randy.

 

forget it Dennis, i didn't see your small text, lmao....

 

It is set up for elevon control right now but I am thinking we may need a rudder. I love the idea of the breaks!
One think I would do different with this design to make it more stable is to have both rotating wings attached to one another on a shaft and have the sleeve in the center so that you get even rotation from both sides at the same time. I was able to loosen the shaft and removed every other washer now they spin great and looks like if you had a long enough runway to get them going you should be fine.
Mark
Here is the pdf I forgot to post Attached files e01c60.pdf (219 KB)Â

 

Hate to rain on the parade here or steal the fire, but I'm going to :twisted:
I went through the design process on this concept back in the 80's from the point of a piece of balsa tumbling to the floor to a working 2ch 1/2A model. No sense in reinventing the wheel so maybe this recollection will help in a successful flight on Mark's redesign of the CL version.

From a CL (control line) point of view this model would(did) fly fine. Mainly because in a CL the roll issue is almost nonexistent. A CL can/needs to be balanced or pulled so it's always trying to bank away from the pilot. Which in this case is done with the bellcrank placed low on the lateral CG. Same goes for the yaw always trying to pull away to keep tight lines, whether it's done via rudder/thrust or line placement in relation to models lateral CG. Having those two factors basically in null and pitch control in real time direct interface, a CL model can really push the 'hey! look what I got to fly' envelope.

When I first bumped a scrap of balsa off the table and watched it tumble at a 5:1 glide ratio I had no idea the concept had been proven a generation earlier. But the spark had lit the flame and the goal was set to make a controllable RC model of the concept.

My first tests were with aspect ratios. Simple stiff paper cut to size. If I recall the higher the ratio the less stable the forward flight path was.(right/left) Quickly there after the drag of rotation counter-acted any benefits of long and narrow. I settled on 6 to 1.

Next was the small crude model test glide phase. It was very apparent very fast that yaw stability was an issue. The tail moment was lengthened to .6 of the wing span (normal sport stuff is .3-.4 max)

Then came roll recovery testing- (same glide models). Basically there was none even if the lateral CG was way low. Which made it to heavy so it had to be done aerodynamically within the wing. So back to the simple stiff paper cut to size tumbling testing. I tried a simple wing-let. To much drag. I tapered and swept that wing-let, that was better but still going in the wrong direction in terms of efficiency. Then I did the full circle tip plate. Not only did it help in rigidity but cleaned up the airflow because the glide ratio and recovery jumped noticeably. Plus it added energy to maintain spin during turbulance. The small crude model test glides with this mod would glide and recover from mild turbulence fine.

The build. The main spar was hardened 1/8 music wire threaded on each end. The ribs were a beautiful shallow 'S' with 3/16x5/8 TE stock. Bushings were used on the ends and a nut on each end of the wire to retain each wing half. The rest of the plane was my stock 1/2A sport fuse and it's equipment. The wing center was build as needed to fit and create a fully interchangeable unit so I could fly the same fuse in fixed or tumble wing form.

First flight. Underpowered :x Mounted up the hot Kustom-Kraftsman 1/2A and it did the same, just went farther. Since there is no incidence to change on this setup I cranked in some serious up thrust in the motor and tacked on more elevator control surface. Why up thrust? Boy did I get the 'no way, your crazy' for that in the pre-flight show and tell. Even after explaining that there is no real wing incidence to fight, and pointing the motor down was not going to help, up was the only answer. Plus I'd be in control of the oversize tail, so it should fly. Couldn't convince them so once again the friendly wagers were placed and once again I had beer money for a month

What I found in that flight was roll stability was very marginal. Anything more than a 15°bank and it would do a roll spin that took a lot of speed increase to recover a solid control feel. It flew kind of like an autogyro with the brakes on. I also knew by the end of the second test of slow speed flight that when the gas ran out I'd be lucky with a 3:1 glide. I kept climbing till it quit and it spun most of the way down till I had enough speed for little over a 2:1 glide with no flare. It was surprisingly noisy.

One more flight. Dihedral, the wing needed dihedral, about 8°-10° at least. I would of liked to of done sweep but with the tip plates that was out. So I removed the wings and mounted stuff in a vise and bent it up. The next flight flew better. Very similar to the youtube link on the Wednesday night phlatbuild. Including the spin at the end I never did another flight, way to inefficient. It was a fun project and I learned a lot about induced drag and how to center and control it for good, not evil


What I should of/would of pursued had there been internet because I made these decades ago.
http://www.youtube.com/watch?v=VWsk98WkmNo
The youtube of a power tumblewing
http://www.youtube.com/watch?v=kPO7OMzuQps

 

whooosh.. hear that sound? that's the wind leaving my sails! JK
This was great information John thank you for taking the time to share it. It is good to know that you have tired this out and learned so much from the experience.
I think there is a long way to go with a design like this, but from you experience and this new build maybe we can figure out a few new things that may help it to work. I think that the physics are there!
Thank you again
Mark

 

The basic parts are there, it's just going to need a few mods to convert it from CL to RC. A couple of simple additions like the wing end-plates and tripling the rudder area. Bending in some dihedral in the rod maybe a challenge, but not impossible. The thrust line issue is still a variable, so I'd make it that way via a pivot and screw locking system. Provided an amble power system it should get around indoors.

I hope you continue with it. I'll gladly help with my 2 cents. (my icon )

John

 

Thanks for your offer to help with this one I think we are going to need it
Mark