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Old Jan 18, 2013, 01:50 PM
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
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Originally Posted by Al M View Post
Tip stalling wasn't an issue when 16%-18% sections were common to fit the servos then available. No washout then.
Good point. Have often wondered about those thick sections - my K-E-os hasn't got one, BTW. They sure would resist stalling at those thicknesses.

D
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Old Jan 18, 2013, 06:55 PM
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Wallingford, Ct
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Thicker sections of the 00XX NACA sections can get to a higher angle of attack than thinner sections for the same speed.

Al
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Old Jan 18, 2013, 10:22 PM
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Oakland township, Michigan
Joined Jun 2005
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Diverging a little, but let me show you my ignorance. Back in the day when I flew control line, we made it a point to have as blunt of a leading edge as possible (and the airfoils were also thick). The reasoning behind that was that the blunt leading edge would allow a higher angle of attack before the onset of stall. This was though to help with the square loops and so forth.

I am currently kit bashing a Blitz MK II which has a pretty heavily tapered wing. Because of the ribs patterns used, as you approach the tip, the leading edge becomes more blunt. I though that maybe the designer had done this to help alleviate tip stalling without having to add wash out. Am I way off? In this case, the airfoil is fairly skinny at the root (~12%) but gets thicker as you approach the tip.

By the way, I am kit bashing the plane so that it looks a little like a Curare. It will have an anhedral stab and a similar fuselage profile. I am building it just for the fun of it.

OK. Now back to Dereck's thread...

Teo

Teo
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Old Jan 19, 2013, 08:32 AM
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United States, NJ, Browns Mills
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Hmmm, got tossed off the forum whilst writing this, so please forgive me if it comes in twice.

Hello, Dereck

I have to say that you've gotten me thinking about the Ulu I'm building. Micki and I have had multiple Kaos', and very much liked the design. I realized that I've adopted some of the Kaos features in the Ulu, including the location of the rudder aft of the elevator TE. Not surprising, as I'd built my last Kaos around 1984, then designed the Ulu around 1990.

I can't say if the Kaos I built had washout or not, as I built them all on a Bridi-style wing jig (didn't have my Ajusto-Jig yet). So, if washout were designed in, I got it! I can say that the Kaos were very resistant to stalls, but would snap and spin violently when desired. I do know I've put washout in every model I've built for many years (other than tailless designs).

All sorts of design features get debated, with their advantages touted or dismissed. Swept LE's versus straight, constant chord versus tapered, etc. But, what it comes down to is the quality of the pilot. I've seen a good pilot with a Quickie 500 win a sizeable pattern contest, defeating a number of "decent' pilots flying "real" Pattern ships.

Do you remember the Tensilon design? A constant chord, simple model designed as a counter to the then-popular Curare model (i.e., the drug tensilon is a cure for curare poisoning). The Tensilon model, with fixed gear and an ordinary engine, was designed as an answer to the high-priced, complex Curare with retracts and a pumped & piped fuel-to-noise converter.

CD
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Old Jan 19, 2013, 09:56 AM
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Commerce Township, MI
Joined Aug 2001
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Link to Tesilon
http://pulling-gz.blogspot.com/2012/...series_73.html
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Old Jan 19, 2013, 10:41 AM
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United States, NJ, Browns Mills
Joined May 2005
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Finally got a chance to take some shots of the Ulu -- things have been a bit slow around here since the furnace went out last night!

Thanks for the link to the Tensilon, Ken. I seriously considered building one when the article came out in RCM. Too bad the wings and canopy aren't available any longer.

CD
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Old Jan 19, 2013, 10:58 AM
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United States, NJ, Browns Mills
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Whoopee, the heat's back on!

Turned out that we needed a new glowplug for the furnace... Never mind, it's back to the BDF!

CD
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Old Jan 19, 2013, 04:18 PM
Visitor from Reality
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Trade you a dead furnace for two short girl children and a hyperactive Granny?

Teo - once got to a British Nats and spent most of the day drooling at the CL aerobatic circles. The build and finish standards are only surpassed by the flying. Watching a model dive off the circle top and square pull-out at five feet is little short of amazing. With a performance envelope like that, stalling is not allowable.

Am hoping that K-E-os does okay on her wing section - circa 13%. I'll either live with it or investigate laser cutting of ribs for a thicker wing...

Love the aft rudder, or is that forward tailplane, look. However, last time I did that to a design, I'd mostly done the plans, got talked into shifting the rudder aft and could barely fit the fuselage into the car. As I've figured out how to make the fus sides from 36" sheet, I will follow a vast number of photos seen of late and stick with the coincidental hinge lines. Ulu is definitely a good looking slinky though.

Ken - will check out that Tesilon. Love the story behind the name!

D
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Old Jan 19, 2013, 04:33 PM
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United States, NJ, Browns Mills
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Quote:
Love the story behind the name!
Gee Dereck, how could I guess you'd like to, umm, how do I say this, "against the flow?" Of course, that goes for all of us who were flying Electrics back in the days of brushed cells and round motors...uh, too much wine there, I think (where's the cross-eyed smilie?).

Your mention of being unable to fit the model in the car brings back memories. I built a Grate Pains CAP .61 way back in 1982-83. It took me three tries to get it to the field, because twice I broke part of it, trying to get up the stairs from the basement at Base Housing. <Sigh>, I should have heeded the message, as the radio quit during the maiden...most expensive turn around the pattern I ever had.

CD
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Old Jan 19, 2013, 09:05 PM
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Tucson, AZ, USA
Joined Sep 2000
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Here it an image of the Kaos I had back in '78. Fiberglass fuse and foam wing tail dragger. Some .40 with a black head, perry pump and tuned pipe. Awesome. Lost it with dumb thumbs practicing the week before a contest.
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Old Jan 20, 2013, 11:38 PM
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Cleveland
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Nice thread, thanks for sharing all the Kaos history and appreciate the build pics.

Dan
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Old Jan 21, 2013, 09:06 AM
Visitor from Reality
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Thank you Dan - there will be build pics when the SU's family horde departs Friday. Right now, my real computer is buried under short pink-ishly inclined clothes and I never did figure out how to get this iThing to demean itself by accepting photos from my Canon.

Soon to lose the BDF to SU's youngest, so 'building' will be a fond memory for this week anyway.

That FG fus Kaos is interesting.

D
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Old Jan 21, 2013, 09:27 AM
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Dereck,
Ive been admiring your work and opinions since Ive joined here. Thanks for sharing!
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Old Jan 21, 2013, 12:19 PM
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United States, NJ, Browns Mills
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Quote:
Soon to lose the BDF to SU's youngest, so 'building' will be a fond memory for this week anyway.
Time to get out the sketch pad (unless the IEtch-a-Sketch has a drawing function) and start drawing up your color scheme!

CD
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Old Jan 21, 2013, 01:23 PM
Visitor from Reality
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Fascinating point here - we could nearly have a forum on this era of model! Have been pleasantly surprised by the interest in my design - it'll be a model soon, I promise - and the interest and knowledge of this era's models.

There's rumour that the COTU (Centre Of The Universe) and her entourage are hitting Chicago's legendary 'Merchandise Mile' for shopping tomorrow. As it's 'beepin' cold here, I shall cry off and see if I can pull off the party trick trio of gluing some wood bits together, photographing them and posting them. The latter could be tricky, as I will have to unearth FRED, my real computer.

Don't ask what FRED stands for - it's a FLA (four letter acronym) I got off a British Army soldier back when PCs were new...

BTW - K-E-OS is actually my second large scale model of an early US 'pattern ship'. The first was a 9/14ths full size scale model of the 'Smog Hog'. If you want to see baffled looks, the likes of Cuban Eights and Avalanches on RET will achieve the aim at most club sites. I even built the combined steerable tailwheel and brake to scale.

Now to go grocery shopping. How can a person waist high to a Hobbit eat so much?

D
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