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Author Topic: Going Flapless  (Read 2267 times)

Offline Steven Kientz

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Going Flapless
« on: November 06, 2008, 02:22:46 PM »
I'm converting a Tower Hobby Fun 51 to control line. My question concerns tail volume. Is there a specific percentage of the total area that should be tail? This model has a 44" WS and 630 sq ". I'm figure that I should increase the tail area to account for the loss of flaps.

Thanks

Steve
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Offline ray copeland

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Re: Going Flapless
« Reply #1 on: November 06, 2008, 08:44:38 PM »
Please post as you go with this adventure, i have been looking at this for some time !!  Great idea , i hope it works out for you , this plane just looks like it should be control line. Wish i could help with your question,, hopefully others in the know will give advice.
Ray from Greensboro, North Carolina , six laps inverted so far with my hand held vertically!!! (forgot to mention, none level!) AMA# 902150

Offline Russell Shaffer

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Re: Going Flapless
« Reply #2 on: November 06, 2008, 09:39:49 PM »
What is the reason for not using the flaps?  I have also been looking at this kit, but I was thinking I would use the kit flaps. 
Russell Shaffer
Klamath Falls, Oregon
Just North of the California border

Offline Geoff Goodworth

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Re: Going Flapless
« Reply #3 on: November 07, 2008, 01:16:25 AM »
G'day guys

I have the kit, and there are no regrets about that, but what I finish with will bear little resemblance to what is in the box. The fuselage is probably OK but the wing is a big low aspect ratio constant chord item with tapered flaps.

I will be reworking the wing extensively to find a bit of realism.

If you are interested but haven't purchased, download the construction manual and see what is involved.

Cheers, Geoff

Offline Russell Shaffer

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Re: Going Flapless
« Reply #4 on: November 07, 2008, 08:32:47 AM »
What engine are you considering?  I was considering a Veco 45 but they are heavy. 
Russell Shaffer
Klamath Falls, Oregon
Just North of the California border

Offline Steven Kientz

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Re: Going Flapless
« Reply #5 on: November 07, 2008, 05:00:24 PM »
I deleted the flaps because I'm fairly new and not sure about setup. Just seems easier( for me) to delete the movement of the flaps and enlarge the tail surfaces. As far as power, probably a OS 46LA. I do have a ST 51(itailan) swap meet purchase that needs an airframe, but probably not this one. An Evo 36 would probably work also.
One thing that I didn't like about the kit was the built up leading edge. If I was to build another I would probably use  leading edge stock or square stock sanded. My LE is really blunt, hope it doesn't cause to many problems.
Will try and post some pictures once I'm a little farther along.

Steve 
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Offline Serge_Krauss

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Re: Going Flapless
« Reply #6 on: November 10, 2008, 01:07:04 PM »
Steve-

Generally, flapless designs have lower tail-volume coefficients, employing smaller areas and shorter tail arms. One reason is that the flaps increase the camber when deflected, and this causes a negative pitching moment which must be overcome by the elevator in turns. If you do not use the flaps, a larger tail might actually inhibit turning ability. I don't know the area of your horizontal tail (stab/elevator), so can't address advisability of any changes, but I'd also look into the speed (wing loading too?) for which this model was originally designed to operate too and compare that to your intended CL speed.  With that ultra-low aspect ratio - 3D?? Anyway, the most important thing discovered around here is that R/C structures in the nose area have too often needed reinforcement; at least one has failed in flight. CL loads are pretty high!

SK

Offline Shultzie

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  • Don Shultz "1969 Nats Sting Ray"
Re: Going Flapless
« Reply #7 on: November 10, 2008, 02:11:14 PM »
Attached photo of the BEST FLAPLESS STUNTER that I have ever had the pleasure to test fly...
I was just one of about 4 flyers that I know of who also took the opportunity to test fly Bob Barons 1968 Nats amazing 19 powered HUMBUG
Not only was I impressed with how it groooooooved in level flight but NOT ONE BIT OF OVERSTEER OR BARBELL BOBBLE in the hard square corners.

Not only watching just how great Bob flew that little "combat model" I could hear and see the buzzz and head shakin' from a whole hole bunch of flyers that were having their thoughts about what CLPA stunt models should look or fly like...Quite humour really, now that I think about it.

So many  R%%%% have been made against...not only Bob Barons amazing flying skills but also Bob had a way of getting inside the  flaps are the only way..."pureist' Nobler school thought folks that view points bordered pretty much on the NARROW side of the slope.

I was quite dissapointed to see Bob not place in the top three at the 68 Nats..HOWEVER that later on became one of the most INFAMOUS nats for rantin'-n-ravin not only against the NAVY JUDGING due to running out of time...due to many weird things...but mostly due to the equally infamous HIGH WIND rule that took up HUGE amounts of wasted air time on the first day of qualifcations. This left little time for flying...plus their way HUGE scoring variations from the two qualifications circles that really had the USUALLY BIG THREE TO FIVE USUAL NATS  WINNERS fretting and fussing!
But in the end...(MY OWN MEAGER CONCEPTWITH A GRAIN OF SALT IN MY VENTURI... from that 68 Nats FEEEAZZZCO' is perhaps the best flyers  AGAIN...ACTUALLY PRETTY MUCH  STILL deserved their BIG 3 WINNING SPOTS , considering how little time was spent training the judging staff of Navy personell..(NO REFLECTION ON THE TRAINING STAFF OF GREAT FLYERS...Bottom line...both the training staff and the Navy judges did the best that they could with such horrific time restrictions.

Enough driviled history...and my condolences for the bad rant on my part.

Attached is Bob's very very different looking  HUMBUG stunt model that I snapped just a few minutes before my film ran out.

Bob Baron contributions to our CLPA have been many....and we are better off from having his ideas and concepts. I think he was one of those forward thinking brave souls that FEARED NOT to TREAD where many souls at those daze days...JUST WOULDN'T GO!
I miss Bob and his passion for Stunt and thanks be to God for sharing him with us for such a brief time on this earth.
Don Shultz

Offline Steven Kientz

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Re: Going Flapless
« Reply #8 on: November 10, 2008, 03:58:52 PM »
I've had to put the plane on the back burner for a couple of weeks( start overtime tomorrow, DEER Season starts this weekend). I've already reinforced the nose during construction( maple engine bearers, ply doublers).My father told me that years ago some kits "flaps were optional" and they flew fine without them. It seems the tail volume will stay at the original size, although it won't be built up.
I had just rounded up materials to start sheeting the wing center and making the flaps, now I get to work 10+ hours a day for several weeks.The high point is hunting with my 69 yr old father(20+ year hunting partner) my brother(14 yr hunting partner) and his 13 yr old daughter( 1st time out!!) I'm very excited!!
Hopefully late next week I can get back in the shop and make some sawdust.

STEVE

 
Steve Kientz
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Offline Jim Pollock

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Re: Going Flapless
« Reply #9 on: January 28, 2009, 08:10:06 PM »
Steve,

Leave the tail area the same, or reduce it slightly, the negative pitching moment of the flaps doesn't need to be over come without them. 

Regarding Bob Baron and his flapless designs.  Of course they were magnificent flyers, but a bit unconventional looking.  I think that had something to do with his lack of success.  The last I saw Bob was at the 98 or 99 Atlanta meet that actually took place in Tifton GA.  He was a judge for Advanced/Expert precision PA, the week before the meet Tom (Morris) and myself had done some practicing together with Tom coaching me.  Well, on my first flight Tom ever the coaching type told me that I had overzealously made my hourglass to tall (sides to vertical),  I went to the scorers table and retrieved my score sheet since I wanted to see how downgraded my score was.  To make a longer story a bit shorter.  Bob Baron had given me a 38 on the hourglass, the other judge gave me a 36, so I took the score card to Tom and said, yup the hourglass wasn't too hot, I only received an average of 37 on it between the two judges.  Tom said, ummmm, I must have been looking at it from an awkward angle!  I replied, I didn't know you were lying down?  We both then busted our guts.  Just shows you can never expect judges to see the same thing you do!

Jim Pollock

Offline Brian Hampton

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Re: Going Flapless
« Reply #10 on: January 29, 2009, 10:54:45 PM »
It's hard to tell looking at photos of that model from the wrong angle but it seems to me that the tail moment is too small to have effective flaps. I remember long ago converting a very nice flying small flapless stunter to flaps and when I tried the first loop it basically just rose like a helicopter. The elevator basically just counteracted the nose down pitching moment while the extra lift from the flaps made it go up :).

Offline Ted Fancher

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Re: Going Flapless
« Reply #11 on: January 30, 2009, 07:44:30 PM »
It's hard to tell looking at photos of that model from the wrong angle but it seems to me that the tail moment is too small to have effective flaps. I remember long ago converting a very nice flying small flapless stunter to flaps and when I tried the first loop it basically just rose like a helicopter. The elevator basically just counteracted the nose down pitching moment while the extra lift from the flaps made it go up :).

Bingo!

Ted

Offline afml

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Re: Going Flapless
« Reply #12 on: January 31, 2009, 09:01:18 AM »
Another Humbug!  No FLAPS!





Wes Eakin

Offline Tom Niebuhr

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Re: Going Flapless
« Reply #13 on: February 01, 2009, 07:43:06 AM »
Wes,

To me the "Humbug" looked like a combat ship with a canopy stuck on it.

Your "Humbug looks great!
AMA 7544

Offline L0U CRANE

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Re: Going Flapless
« Reply #14 on: February 02, 2009, 06:08:56 PM »
If you get a chance to read over the mag article on Bob B's HumBug, you'll find a lot worth thinking about.

The minimal approach, ASIR, was part of the mix. Bob and Wild Bill Netzeband coordinated on developing the model for the express purpose of developing a model that would most likely come closer to the rulebook requirements for the maneuvers than anything else.

I'll have to dig it out and read it again, now... I recall one thing specifically - I think Bob Baron mentioned that the model was trimmed so sensitively that he could see his pulse reflected in the flight path! Of course, he was an exceptional flier, and could handle the model trimmed so 'quick.' Plus, from the handle, he could see things that the rest of us could not...

Aside from the radically different overall look of the 'Bug, from all angles, there was that howling VECO .19 out front. Didn't sound like a Fox 35, OS 35S, or ST46, at all. Distracting? Perhaps... And our judges have improved nicely since that time - less influenced by actually irrelevant factors, despite a deeper awareness of "mainstream" practices, appearance and model shapes. The poor swabbies, hurriedly trained to judge something unfamiliar, could only go by how they WERE trained. A loud, screaming model that looked drastically different from the ones they were trained on, flew faster, and didn't fly the corners and rounds the same way? They couldn't know if the oddball was better or worse, only that it was NOT what they were trained to judge.

The legendary NAVY Nats were somethig special, in many ways. There were several model construction articles that ranted on about how to "psyche" the (junior enlisted) Navy judges. One is quite amusing - the designer (name will float up to the window in my OLD Magic Eightball, shortly, I expect) designed his model to somewhat resemble a USN jet fighter, and decorated it with panel lines, maintenance legends and national insignia to make the impression deeper. Many of the models were 'presented' on the same theory.

(AHA! Magic Eightball window says: designer - Jim Kostecky, model -Talon, a Flying Models featured article.)

When the "better" fliers got to the Nats, they found a bunch of not-particularly-charmed junior USN 'ratings' with the clipboards. Guys who thought volunteering to judge a toy airplane contest would be a rest from the junior sailor's usual ration of BS and Chicken-excretion, but found it meant standing out in the hot sun on a paved runway all day, for several days. Not the most motivated group you might wish for, but they did very well, regardless.

Jim K mentioned that these judges were tired of smart-a** junior Officers, who climbed into the Navy jets it took muchos hours of junior enlisted sweat to get ready for them to take up and butcher... ...And all these toy airplane guys were dressed in whites, just like aforesaid Officers, and were flying model airplanes that looked like those hated jets the (Army term is "grunts") 'teams' prepped and repaired for those snot-nose aforesaid junior Officers...

Another negative? Sure, but the US Navy has a tradition of meeting and surviving such, right Ty? Jim K thought he might do better if he went out there in "earth shoes, cut-off blue jeans, some sort of political comment Tee-shirt, and granny glasses," which would resonate with the (oh no! not disaffected!) (less than happy?)  judges. Jim flew well, anyhow. The model has a definite life in the Classic category.

When we started to enlist (oops! sounds like dodging the draft - which no longer exists - by the way. ...by joining up before they order you into uniform), knowledgeable judges from within the Stunt Community, also about timed with the end of Navy Nats, we got a steady improvement in quality, nationwide, and reduced regional differences in standards. However, in regard to models like the HumBug, there was a built-in expectation of how a model should look, should corner, should sound. Anything less was, at least, a distraction. It might raise a sense of bias-against...
\BEST\LOU

Offline Jim Pollock

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Re: Going Flapless
« Reply #15 on: February 03, 2009, 04:47:14 PM »
Lou,

E - X - A - C - T - L - Y - !

Jim Pollock   ;)

Offline afml

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Re: Going Flapless
« Reply #16 on: February 09, 2009, 06:22:56 PM »
Wes,

Your "Humbug looks great!

Thanks Tom!
Kinda looks like a "streak" rudder. LOL!
Flies GREAT! Turns on a dime and gives back the change!
 #^
Wes Eakin

Offline RogerGreene

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Re: Going Flapless
« Reply #17 on: August 24, 2009, 10:51:11 AM »
Can you give the location mounting of the landing gear, ie, wing mounted or fuselage mounted? Also, what is the span?

Thanks,

Roger
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Offline Steven Kientz

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Re: Going Flapless
« Reply #18 on: August 24, 2009, 03:21:21 PM »
Roger,
  If you are asking about the Tower Fun 51 it has fuse mounted gear and a 44" WS( I think). I have put this ship away until winter. Have spent the last several months destroying my Tutor II and a Pyscho combat plane. The wing from the Tutor is repairable(LE sheeting has a small hole). The Pyscho was way tail heavy(cg 1.75" aft of recommended point, HOW DID I MISS THAT??).
 Am currently trying to build an enlarged version of a slow combat plane" Spider". 52" WS(with tips)  with a rib length of 11". Powered by a TT pro .36 or an Evo .36, not sure which yet.
Steve
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Offline RogerGreene

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Re: Going Flapless
« Reply #19 on: August 24, 2009, 05:56:46 PM »
Thanks Steven for the info. :)

Sorry I didn't say to whom I was addressing. I should have adddressed,

AFML who had the photos of the Red white and orange 71 Humbug.  Where is the landing gear mounted, fuselage or wing? Hard to tell in the photos. And what is the span?

Sorry for the confusion all.

Thanks,
Roger
Fly Stunt <><
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USAF Veteran 1962-66 SAC
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Offline john e. holliday

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Re: Going Flapless
« Reply #20 on: August 25, 2009, 11:38:26 AM »
Looks like wing mounted gear from what I see.  I want to know where the plans are.  Guess I will have to check AMA site.   DOC Holliday

PS:Have all the ribs for my next Humbug.  Will be forty powered this time so I can get blade diameter for pull.  jeh
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Offline John Miller

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Re: Going Flapless
« Reply #21 on: August 25, 2009, 02:52:00 PM »
From a clolse inspection of the secondpicture, I believe the plane has fuse mounted gear. It appears to be colored black so they are hard to see.
Getting a line on life. AMA 1601

Offline afml

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Re: Going Flapless
« Reply #22 on: August 25, 2009, 08:31:33 PM »
Where is the landing gear mounted, fuselage or wing? Hard to tell in the photos. And what is the span?

Hi Rodger,

The landing gear is fuse mounted, 58" wingspan, 700 Sq". Bob took 4th at the 1971 Nats. Bob covered it with monocote, it weighed 51 oz and was powered by a series 21, McCoy 40. Plans by Tom Dixon. H^^

"Tight Lines!"

Wes
Wes Eakin

Offline RogerGreene

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Re: Going Flapless
« Reply #23 on: August 25, 2009, 10:19:47 PM »
Thanks Wes, for the info. Great looking plane.

Roger
Fly Stunt <><
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USAF Veteran 1962-66 SAC
Life is 10% what happens to you and 90% of how you react to it. FAA #FA3RFLPAN7

Offline PerttiMe

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Re: Going Flapless
« Reply #24 on: October 19, 2009, 09:08:04 AM »
Speaking of the Humbug...

Flystunt (Bradley Walker?) has a page on "Humbug 60"
http://www.flystunt.com/AIRPLANE/BARON'S%20HUMBUG%2060.htm

AMA has a plan for a "Humbug 666": .51 power spans 53 inches
http://www.modelaircraft.org/plans/plans95.aspx

(not sure how different these are)

Barry Baxter sells a plan for something called "Baron": 3.5cc (.21) stunter. 40.5" wingspan, 375 sq.in. I could swear it is related, even though it has flaps.
http://www.controllineplans.com/stuntpage1.htm

*** Some seem to be flying a flapless plane called TEOSAWKI: looks otherwise totally different from the Humbugs. Ugly, they say. I am sure it could be pretty with a nice fuselage...
I built a Blue Pants as a kid. Wish I still had it. Might even learn to fly it.


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