Sir Crashalot

Hello all!

My plan is to follow in the foot steps of fellow RCU member dicknadine, and enlarge Roy Clough’s Hoopskirt plane to a large enough size so as to be flown with standard size three, or four channel radio, and an old OS .25. Need help determining the necessary diameter, as well as cord length of the wing. Problem is, I don’t have any knowledge of the characteristics of the annular wing. Lift, drag, etc. The original Hoopskirt plan is posted below for your information. A free flight model that uses a .020 for power and looks light as a feather. The main question being, how much lift is this wing going to provide. Any and all input is welcome.

Also below is dicknadine’s enlarged hoopskirt model, still in the bones. I believe he said that he never had the chance to maiden it due to losing it to Hurricane Katrina. So flight characteristics at this size remain unknown.

Thanks

Bob J.

Tall Paul

The model looks like it would fly nicely with a 400 outrunner on 3 cells.
Built light of course.
I'd make provisions for "aero-keels".... airfoil shaped things that stick out to the sides of the barrel, in case it doesn't want to fly. The same chord as the barrel, and maybe a chord of span, with one on each side.

Sir Crashalot

Paul

Thanks for your reply. As far as the extended wing tips, (“aero-keels”), I agree with you completely. I already had something like this in mind as a plan “B” as well.

Thanks

Bob J.

BMatthews

Well, it's basically a 2.5 winger thanks to the center wing and the hoop. For a .25 I'd size the top view so it has around 200 sq inches of area. That'll give it the equivalent of 500'ish square inches to fly on. Ailerons on the center flat wing and normal tail surfaces. And be sure to cover or paint the ring with some distinctive color bands to tell up from down and right from left.

And if this one doesn't totally discombubilate your mind then maybe you want to have a go at this one.....

Sir Crashalot

Bruce

Thanks for your reply. It will help me zero in on the necessary dimensions. Another question I have is about the vertical fin on the top of the hoop. In the original thread, here on RCU, someone posted the magazine article. It stated that the fin gave the aircraft stability, like dihedral would do on a standard type wing. So, since I’m going to be adding ailerons, I’m not sure if the fin will be necessary. Any thoughts??

Thanks

Bob J.

BMatthews

Because of the perspective issues you may want to include it at first. If nothing else it should help provide a reference to which way is supposed to be up. Once you get past that then cut it off. Just don't lose count of the rolls....

Sir Crashalot

Bruce

I think you're right. Roy was an amazing designer. He included it for a reason. The design being so symmetrical, it’s gonna want to roll quite easily. The vertical fin is there to counteract that tendency to roll. Which is most likely caused by the engine torque. With this model, the prop will be stationary, and the plane will be spinning! Thinking about it now, I think the fin will be a permanent fixture.

Thanks

Bob J.

iron eagel

A fellow club member built his own version of one of these a couple of years ago. His version had astraight centered tail extending from the motor mount, rather than the dual booms. It also had fully functional control surfaces for aileron, elevator, throttle and rudder, as well as two main landing gear an a tail wheel. It flew very well except it really did not turn well, he had to enlarge both the fin and rudder area well beyond double of the original area in order for it to respond to rudder inputs. Originaly it would track straight even with full rudder and got blown around in the wind quite a bit. But after those mods and a bit of side surface to the portion of the fuselage that the rudder was mounted on it flew very well. His version was roghly the same size as the one in the picture built by Dick, and it was built very light powered by a .25 or .30 engine, it would do almost any aerobatic move that a convential airplane could do.

Sir Crashalot

iron eagle

Thank you for your input. During the design stage of this project, I thought about using a single fuse also. A more modern “look” if you will. But decided to stick to the basic design. Only to preserve the vintage flavor of the original. However, a single fuse annular wing aircraft may still be in my future. It depends on how much fun I have with this one!

The tip on the vertical stabilizer, and rudder size is a good one. Will enlarge this area to ensure control. I can see how this design would want to nose into the wind, and stay there.

Could you tell me about the flight characteristics? Was it a slow floater? Or was it fairly quick, given its oddball shape.

Thanks again

Bob J.

iron eagel

The plane was very lightweight as are any of the planes that this guy has built, so it would float but also seemed to have a lot of throttle left when you were at cruise.
But given the lightweight construction I really do not think it is by any means a "barn burner".
I was just intrigued by the whole thing to be honest.
I will ask him about it the next time I see him at the field.
He was not really pushing it at the time I saw it as he had just made the changes to the tail surfaces.
I can tell you this!
Paint/color it so you can follow it in the air, because if you fly it at any real distance, it gets hard to stay oriented with it.
A lot like Bruce's "Which Way"....

iron eagel

I also recall that he had added some "Aero Keels" as Tall Paul suggested, and build an airfoil shape to which the ailerons were mounted on instead the flat piece of balsa within the hoop behind motor.
It would float to a point, over all it flew like a box kite with control surfaces and a motor. But as I said it was very lightweight!

Sir Crashalot

iron eagle

Once again, thank you for your input. I was wondering what to expect, as far as the flight characteristics was concerned. Thanks for the “heads up”!

It’s always good to see how other builders enhance an original design. At this point, there are still a lot of decisions to be made. Not sure what features I’ll need to incorporate to have a nice flying model. Would like to keep it as close to the original as possible. However, it still needs to be able to get off the ground!

Thanks!

iron eagel

I personaly would not be concerned about the ability of any of Roy Clough’s designs being able to fly.
Despite how odd they may appear any that I have seen have all flown.
How well they fly when adapted to todays equipment and materials can be an issue.
I would build one close to stock as possible including what provisions that you want to have regarding control, and use that as your test bed.
Where it is not all that complicate a build despite its unique design it is not like you will be wasting months of time building a model only to find that it does not perform as you want it to.
The nice part of the hobby for me is to be able to take a know design and refine or bash it to give it my own flavor, or to adapt it for my own purpose.
The only problem for me is time to do all of the projects that I have in mind or am working on, or want to do.
If you would during your build post some updates please, I am interested in this particular design, and would be very interested in what you find out about it.
Thanks
Paul

Sir Crashalot

iron eagle

Paul, my concern isn’t about Roy Clough’s design as much as my own ability to successfully build something that’s going to fly!

But as you say, the good thing is this isn’t a major build. Once all the design features have been finalized, I think I can knock it out fairly quick. So if a major design change becomes necessary, it’s not a huge loss of time.

I recently received a new digital camera as a gift from my wife. (Birthday) It should be good enough to post some pictures. Will definitely keep you informed!

Once again, thanks for your input.

Bob J.

iron eagel

Thanks,
This is one design I would like to try to update sometime in the future, and any information you would be willing to share would be helpful.