efish

My Feedback: (5)

Hi, thanks to a radio frequency conflict, my trusty old Sig Wonder has planted itself into the ground and is now beyond repair. I'm crestfallen, as I had come to like the plane quite a bit for simple no fuss flying.

Now I'm looking for a replacement. Unfortunately, Wonders are no longer available locally; anyhow, it would not be too difficult for me to scratch build another. But I always wondered if the Wonder could be improved - how about a rudder for stall turns, perhaps flaperons/spoilerons for those abrupt descents and some landing gear to shoot touch and goes?

Well, I just saw a Marutaka Sunfish kit in the LHS. Can't seem to find a picture on line, but imagine a low wing Wonder with a single tail that looks quite a bit like a mola-mola on trike gear. Interesting thing is that the Sunfish has a rudder, elevator and ailerons, Well, actually, it looks like the designer cut the strip ailerons in half and used the inboard halves as elevators and the outboard halves as ailerons. I'm gussing elevon mixing was a little less common 20 years ago when the kit was probably produced.

Anyhow, sorry for the long story, but I was thinking about scratch building something like the Wonder, but this time low wing, with a single tail equipped with a rudder. Using the setup of the Sunfish, I would then use 1 servo for the elevator halves and 2 servos for each aileron. Airfoil would be similar to that of the Wonder - symmetrical, but pretty thick. Power would be a .25FSR, a .25FX or a .32SX, depending on finished weight.

The questions:-

1. Would a rudder on something like this be able to perform a stall turn? How effective would it be? I know fuselage area is rather lacking, but with enough power, is it likely that I might be able to fly knife edge as well?

2. How would the Sunfish elevator/aileron setup work out? On a 'normal' plane, the elevators would actually be flaps. What would happen if I tried to land with them - would the plane just "float" in?

3. Would it be better just to set up the strip ailerons as "elevons" as on a delta?

4. Or should I go mad and set up the four control surfaces as "quad flaps" not sure what that would do, and I'm sure there will be lots of complicated mixing required, but the thought of being able to activate crow mixing just before landing is pretty wild.

Thanks.

Dsegal

I lengthened the fuselage on my Wonder and loved the plane's performance. See the thread at http://www.rcuniverse.com/forum/m_38.../tm.htm#384438

dieFluggeister

There's no reason you could not introduce a rudder on your new plane keeping in mind that with a short moment arm you would need proportionately larger control surfaces. Stall turns would be possible, knife edge would be poor and at a high angle relying on thrust to maintain altitude.

It's hard to picture the sunfish for me but the setup you describe seems inefficient at best. If the wing planform is rectangular, I think you would run into pitch control issues. !QUOT!Squirrelly!QUOT! I believe is the technical term. Scrounge up a pic maybe? For something really different, a forward swept wing with inboard 'elevator' and outboard ailerons might offer more control if you want to go with only a v-stab for a tail. Of course a delta planform is tried and true.

You can make almost any conventional setup plane into a !QUOT!Wonder!QUOT! type plane using a symmetrical or semisymmetrical airfoil and by shortening the tail moments and enlarging the areas. Here's bash I did last year. You could do it as a low wing too I suppose.

efish

My Feedback: (5)

Thanks Dave - great looking "wonder"! Kinda like the lines and the flying characteristics of the orginal though. I'm still quite a newbie, but the stock Wonder with a .25 FSR was just great fun!

dieFluggeister, ah yes, almost forgot I had seen some "Wonders" in the 1/2A forum. Out of curiosity, how does your 1/2A wonder fly compared to the DNU? I loved my DNU dearly and pending the decision on this plane/wing/whatever, was going to build another just cuz it's quickand easy to build, yet flies so amazingly well. Mine had a rudder and throttle too, so stall turns were a blast.

It's windy glider season here for the next coupla months, so I was reallly thinking of a larger plane (about .25 to .32) to deal with the wind. Also found that I could hand flip start my old .25FSR a lot quicker than I could a little 0.061 screamer.

The Sunfish has a tapered wing (swept back). Will try to go down to the shop and sneal a photo of the box cover tommorrow. The kit was probably produced about 20 years ago and this would likely be my last shot at owning one. Just want to be sure it doesn't turn out to be an unflyable dog!

Tall Paul

I had a rudder (both rudders) on one of my Wonders.
Made a fun plane funner!

dieFluggeister

Efish, the 1/2A DNU mod 'Das Wunder' has performance similar to the DNU in that it is a stable and predictable flyer. It likes the speed though and gets lazy below 1/3 throttle. Pitch control is more brisk and with a shortened wing and .061, wing loading is higher giving it higher speed and better handling in wind. Roll rate is about the same as the original but not as quick as a Sig Wonder. Stalls are very gentle and mushy with no tip stall. Power off glides are steeper and require a little more speed at landing. Inverted flight ok, and vertical performance is very good.

Johng

My Feedback: (4)

Don't you have the plans for the old Wonder? I'd use the busted parts as a form and just cut new ones. Want to build even quicker? Hot wire a foam wing. Maybe even EPP.

My old wonder had a 25 fp on it and it was essentially a jet trainer. Did a mean rolling circle. I put rudders on it, just 3/4 strip scabbed onto the TE of the verticals. I stuck an HS-81 on the centerline of the plane and ran straight pushrods out to the rudders at a 45 deg, right out in the breeze. Stupid simple.

It would do a flat spin with those rudders that was like a frisbee falling out of the sky. Maybe a different CG or larger elev and it would have done a climbing spin. A high speed snap was rediculous. Better have different colors top & bottom.

A friend put a 25 FX with a pipe on his, and it was making the local livestock sterile. It had so much excess power, that it was at aerodynamic terminal speed the whole flight. It climbed, leveled and dived at the same speed. Just rippin. It lasted less than a season before something pulled apart.

I've got some old 6" think white foam 4x8's that were abandoned at a construction site. I've always wanted to make a G-62 size wonder with that stuff.

Johng

My Feedback: (4)

Oh, and any spoileron/ flaperon action would create big changes in pitch when used. So, I would stay away from that.

efish

My Feedback: (5)

Hi guys, thanks for the info; still undecided, but I managed to snap a picture in the shop this morning.

Whadday think? Flyable? Marutaka kits have a small cult followng here, though I've found that the wood used in the kits are a little (very) heavy. I would be surprised if the Sunfish turned out to be a dud, but I'm interested to hear your views.

Johng

My Feedback: (4)

butt-ugly. And I don't think that pic is genuine. The two wing halves look like different designs.

Dude, bash up a son-of-wonder. Or try the Lanier Shrike. It is very Wonder-like

dieFluggeister

Well, I see now what you mean with the aileron, elevator split. The picture made the wings look skewed so at first I thought it might be control line, but I see its 4 ch. Thats one weird looking bird....fish.... whatever.

Anyway, if you are curious and have the money then I say 'go for it'. The hobby is all about learning and having fun right? It may be the star of the field or it may be a clown in a circus but either way it's going to be a hoot.

efish

My Feedback: (5)

John -the picture is very real! Even took the plans out of the box to have a look. The distortion is more than likely caused by the angle at which I was holding the box.

Yes, it is kinda ugly. Guess it'll be sort of like the Lazy Bee I take out now and then. Everyone around the field just stops for a while and stares really hard at the big ugly angry buzzing bee! Never fails.

Price wise, it'll cost about the same as a Sig Wonder, so its not real expensive, considering that it comes with a reasonably complete hardware package. One trade off about spending time in an office is that planes suddenly seem that much more affordable.

Yes, dieFluggeister, curiosity is a big part, but at least on paper, it does seem to offer a little more varied flight performance than the old Wonder. Always lamented the lack of a rudder.

That said, I think I will go build up another DNU first - just loved throwing the little red thing all over the sky!

Leif Ancker

Have a Bill Evans type flying wing glider (Plank type, reflexed airfoil). Wings orignal, fuselage reconstructed from memory. Elevators, rudder and throttle. Need to know how to locate the CG. Have been told anywhere from 5% to 25% of mean chord. Anybody have an idea? I'd hate to crunch it on its second attempt as I did on the first.

Tall Paul

If the plane has a true horizontal, you might start with the c.g. at 25%.

Checksix!

My Feedback: (1)

Those Evans planes all balanced at 16-18% of the chord

Leif Ancker

To Tall Paul,
16 to 18%! OK. And thanks a lot. I'd hate to try destroyinmg it a second time.
Leif Ancker