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Old Sep 23, 2012, 07:45 PM
Addicted to 3DHS and EF
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ohio
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Originally Posted by tic View Post
I remember the good old days when snowboards were BANNED at many ski areas. I love watching the boarders waddle and struggle to the chairlifts in the most awkward biomechanical fashion ever seen . Baggy pants, hoodies and all, they are the epitome of the zagi generations values. Good post Eclipse!
I suspect you are the same type of person who can not stand 3D flyers like myself?
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Old Sep 23, 2012, 07:58 PM
OFF TOPIC POSTER
Des Moines IA
Joined Dec 2005
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What is going on here ? no mention of razor blades and skate boards.
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Old Sep 23, 2012, 08:00 PM
OFF TOPIC POSTER
Des Moines IA
Joined Dec 2005
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Originally Posted by 3Daddict View Post
I suspect you are the same type of person who can not stand 3D flyers like myself?
As you are new here.tic hates them new fangled flying thingies and I'm sure he has never seen a 3d movie.
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Old Sep 23, 2012, 08:09 PM
tic
thunderscreech
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New Cumberland, PA. US
Joined Dec 2000
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If God had wanted to planes to fly backwards and do crazy things, seagulls would be doing aerobatics over the boardwalks . Let's see what other generalizations we can come up with for what "type" of person I am.
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Old Sep 23, 2012, 08:16 PM
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Des Moines IA
Joined Dec 2005
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I dono lets ask mopar69 he might be able to help AKA Lain.
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Old Sep 23, 2012, 09:25 PM
Electric Coolhunter
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United States, TX, Fort Worth
Joined Jun 2000
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Quote:
Originally Posted by JetPlaneFlyer View Post
Thomas.. Have you got any references to back this up?
I did a bit of Googling and according to the official records of the 1952 19th US National Soaring Championship a Ross-Johnson RJ-5 (a conventional tailed sailplane design) won the event and Schweizer SGS 1-23's came second, third and fourth. I found no reference to a Horten even competing that year or in fact any year around that date The RJ-5 also won in 1950, 1951 and 1954 with the SGS 1-23 winning in 1953.
I did misremember that detail...he actually came in 7th in the 1952 Soaring Nationals after a navigational error cost him a higher position. He did win two other major US soaring events that year, which I believe was the only year the Ho.IV was campaigned to any degree. I simply misremembered which events it won. It was turned over to the University of Mississippi for testing after the 1952 contest season.

Still a very respectable and successful performance for the only flying wing campaigned that year.

http://www.nurflugel.com/Nurflugel/H...v_a_blurb.html

It did have one of the highest L/D ratings, if not the highest, of any sailplane of that time period.
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Old Sep 23, 2012, 10:26 PM
VOLTS > AMPS
stgdz's Avatar
United States, MN, Buffalo
Joined Jul 2011
3,866 Posts
speaking if chasing things, at lunch one day i was flying the little slick in high alpha and must have rustled up some geese. Stupid intercontinental grass powered sh1ting machines crapped all kver the baseball diamond.

Anyways after that a couple of walkers were wondering if i scared them away. I said yes but i didn't know they were there. There response......


"can you come back tomorrow those things are quite the nuisance!"
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Old Sep 23, 2012, 11:35 PM
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United States, CA, Oakland
Joined Dec 2002
2,333 Posts
Hey now,
Some interesting bits between this morning and now. Some valid and some not so much.
A few bits: high speed props, edfs, and such are all noisy. Not so. Pusher speed props are noisy because of the choppy air they have to deal with combined with the sound board effect of the foamy wing. In my Arrownne P-5 F5D hollow molded racer I'm running a four seven square prop on a 3700kv motor on three cells. It's very quiet at full tic. Not silent sure but no louder than a sport outrunner swinging a large prop slowly.
EDFs and noise. Mostly that's a similar issue to the pusher foamies. Often a foam eflux tube, or thin plastic in a foamie. And a plastic somewhat out of balanced EDF unit with huge gaps between the blades and the shroud. Lots of vibration = lots of noise. In my Sapac Viper (glass fuse) 70mm EDF jet I'm running a Mach billit aluminum fan unit with very tight tolerances. While not super quiet it's not at all noisy. No more than your average sport prop plane anyway.
While you do get some noise from prop tips going super sonic you get far more from vibration. If you have a solid airframe, stiff motor mount, stiff solid prop or impellor you'll have fairly low noise. On my F5D plane I lost thirty Db by swaping a APC prop for a carbon Cam prop. Much stiffer. Much quieter.

I'm no aerodynami engineer but according to the good folks at the TWITT (the wing is the thing) group, a full size EAA site. Properly designed 'wings are far cleaner than conventional aircraft. (I personally can't say) the reason most aircraft are conventional aircraft are the shape they are is that people are used to that shape and don't trust wierd designs.
I didn't believe this untill I got into wierd model shapes. Then I ran into a lot of the "that thing won't fly" or "won't fly well" crowd. My taileds racers often beat out connies in their class and several of my stunters did very well in contests compared to connies.

Now I'm not really a 'wing guy. I do like oddball planes and will give up some performance for wierd. I like canards even with their problems. But tailess aircraft be they planks or cranked carry a lot less drag than connies and in speed games that is a big advantage.

Oh and the stability issues we used to have with wings have been over come with the nifty new. I putor aided flight systems like those used in the B2.
RobII
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Old Sep 24, 2012, 12:31 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
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Quote:
Originally Posted by Thomas B View Post
Still a very respectable and successful performance for the only flying wing campaigned that year.

http://www.nurflugel.com/Nurflugel/H...v_a_blurb.html

It did have one of the highest L/D ratings, if not the highest, of any sailplane of that time period.
'Respectable' yes but nothing ground breaking. The best conventional gliders of the day (e.g the 1938 Cirrus in Germany and the RG-5 in the US) had glide slopes of 1:37 or a little over. The Ho-IV was according to the article you linked about 1:32, a significant deficit.
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Old Sep 24, 2012, 12:50 AM
Wake up, feel pulse, be happy!
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United States, AK, Fairbanks
Joined Aug 2009
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Quote:
But tailess aircraft be they planks or cranked carry a lot less drag than connies and in speed games that is a big advantage.
So why are all the top F5D competition ships conventionally-styled?
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Old Sep 24, 2012, 06:12 AM
Addicted to 3DHS and EF
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ohio
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Quote:
Originally Posted by tic View Post
If God had wanted to planes to fly backwards and do crazy things, seagulls would be doing aerobatics over the boardwalks . Let's see what other generalizations we can come up with for what "type" of person I am.
haha how did you come up with that.
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Old Sep 24, 2012, 07:34 AM
Taranis Tyro...
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United Kingdom, England, Hitchin
Joined Jan 2004
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I'm not normally one for quoting Wikipedia (a fair percentage of what's up there is questionable), but on this subject there do seem to be a couple of pages that summarise the theoretical advantages and real world disadvantages well:
In summary there are theoretical advantages to wings if all you want to do is cruise in a straight line at medium speeds, but in most instances these are negated by the need to mitigate the pitch and yaw stability issues and the need to carry the required payload within a small internal volume (admittedly the latter is not often a problem with models though). If manouvreability and high speed are your prioritiesthen a conventional setup will be much safer and more efficient (as pointed out by Tetracarbon's F5D example).
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Last edited by MattyB; Sep 24, 2012 at 09:35 AM.
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Old Sep 24, 2012, 08:04 AM
An itch?. Scratch build.
eflightray's Avatar
South Wales U.K.
Joined Mar 2003
13,188 Posts
the scourge of RC ?

There are flying wings, (or should I say wings that 'fly?' ), but then there are flying wings.
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Old Sep 24, 2012, 10:48 AM
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United States, FL, Lehigh Acres
Joined Aug 2011
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someone got out of the wrong side of the bed lol.
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Old Sep 24, 2012, 11:31 AM
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United States, CA, Oakland
Joined Dec 2002
2,333 Posts
Quote:
Originally Posted by C₄H₁₀ View Post
So why are all the top F5D competition ships conventionally-styled?
Hey now,
Simple answer; they aren't. Longer answer; every few years a new tailess racer comes around and generally does quite well against the connies. Um, a few years is a quick turn around for a race design.
But there are other issues in F5D other than just low drag and absolute speed. For one the rules favor connies. Wing area, weight limits, battery shape etc come into play. Add into that the hyper critical set up required for tailess aircraft and you begin to see why there aren't more of them. But for those who go through the trouble of designing and testing such models they do very well. And for those who take the time and trouble to build and properly set up others designs, they do fairly well too.
Now I'm not a serious tailess freak, I just like oddball aircraft, but I've owned and campained three or four tailess F5D models over the years. I've done well and had good fun with them too.
RobII
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