flat plate airfoils

[rcsoar4fun]

I was digging through some plans this afternoon and found a couple of speed 400 airplanes. One is a BAE Hawk and the other is a Tucano, from one of the English mags. Both use 1/4" solid balsa wings. Any one used this type of foil before? I was thinking the Hawk would be a cool home for my Norvel .061.

Kristopher

[steve lewin]

That wing construction is pretty common at least in the UK. Thousands of those particular planes have been built along with the similar construction Hunter, Spitfire and ME109 also published in RCM&E.

You wouldn't be the first to convert one to wet power. I've seen several converted Tucanos and if anything they're almost overpowered with an 061. Don't remember an IC Hawk, do Norvels work well as pushers ? If they do there's always the Hawker Hunter published in the same mag, a much prettier plane IMO.

Steve

[soarrich]

I've built a couple using the 1/4" sheet wings. My Sapphire 400 is electric, my StaggerThing is Norvel .061. I haven't flown the StaggerThing yet, but I flew the Sapphire 400 a lot, it's very fast, flies great. You don't need any stinking airfoil!

http://www.netlabs.net/hp/soarrich/Sapphire400.html

[T. Lyttle]

I seem to remember a rather extensive thread about this; try a search, it's been in the last year.

Flat plates work fine for 1/2A models, r/c, c/l ,or freeflight, easily built, very fast, simply repaired, other than that, of no value....

[rcsoar4fun]

That bipe is pretty cool. Own design or from plans? Any plans to fly it soon?

Kristopher

[soarrich]

No plans, it was built for RC Universe's 1/2adesign contest. I've been reluctant to fly it because I made the tail so long that with the short radial cowl it took 3oz of lead to balance it, making it heavier than I wanted it. I will fly it though this winter.

[Bipe Flier]

Hey Soarrich, I've been wondering how the Staggerthing flies. You'll definately have to post the results after you test fly it.

[phat23]

"Flat plates work fine for 1/2A models, r/c, c/l ,or freeflight, easily built, very fast, simply repaired, other than that, of no value.... "


T. Lyttle:
Why do you say "other than that, of no value...." ?

[T. Lyttle]

Facetious, old boy, trying (unsuccessfully, it seems) to be funny!

Biggest surprise for me with flat plate was building and flying a Sarpolus design for c/l, performance was quite remarkable. Built a Honker or two for r/c, and was very impressed. Once over a certain size, though, a Jedelsky is far less likely to warp and is much stronger. Freeflight HLGs use sheet wings, and sanded-in airfoils with great success; many other designs have come out over the years for hlgs with built-up wings, but few were notable (someone's gonna call me a liar on that one!).

[CrocEnd]

GENT'S This is what should be flying by the week end. Called catupult gliders (with speed)Mine is the Hawk done from the plans in said mag.Have totally re done bungee launch for more twang,
let go lbs showing fish scales 24 lbs.

[Bill Glover]

Originally posted by rcsoar4fun
One is a BAE Hawk and the other is a Tucano, from one of the English mags. Both use 1/4" solid balsa wings.

BTW "Solid balsa" and "flat plate" are not necessarily the same thing! From memory, both those models (and many others like them) have the upper surface of the wing carved/sanded to give a thin flat-bottomed (lifting) section. That's not the same as a flat plate, where the upper and lower surfaces are parallel.

Real flat plates are less efficient but can work OK on small and/or fast-flying models (I have a delta and a flying saucer, both made from foam board).

[T. Lyttle]

Yeah, foamboard is cheap (real estate signs when no one's lookin'), light, and durable. A chum built a B1 lookalike for 049, flew like a dream; I have his sketches around.... someplace...

I built the Gnat from the RM plan, never got to fly it (personal disaster time), and that's right about thin airfoil/flat plate, not the same thing, and HLG teaches you that right away: try 0/0 incidence with flat plate and you have a lawn dart, but sand the wing into an airfoil and plan on losing that model...

[coffeemug]

That StaggerThing looks very nice soarrich, can I ask what the weight turned out to be?

[heymanwatchis]

I've recently finished a .15 sized 3D "trainer" from blue fan-fold. I'ts very cheap, relatively easy to build and flies great. If you don't plan on flying it long, you could slap one together in 2 hours RTF. That is if you don't cover it. I've noticed , though, that fuel soaks into the foam at the cut edges and through the perforations in the film that comes on the foam. It doesn't attack the foam, but can make it mushy and heavy after a while.
My 3-D trainer has roughly 550 square inches, weighs <2 lbs, and torque rolls on a .15 OS engine. I used micro servos with lots of control surface area in front of the hinge line to help the little servos throw. Also, I used a TP 800 mah li-po battery with a cheap GWS speed controll with BEC to save weight and give plenty of flight time. Nife-edge, torque rolls, loops- in and out, etc. Oh yeah, I used two CF arrow shafts for spars. Zero flex.