Scale Stunt

Some of the posts on flying scale-like stunters got me to thinking.
Why not an event for Scale stunters? Having tried, it's pretty obvious that a true scale plane will be too heavy to do the current pattern very well. Making a highly capable plane means turning it into a cariacature of scale. So the idea would be to use a modified pattern, with more emphasis on round maneuvers, perhaps a touch and go, etc. Make the flight pattern somewhere about half of the score.

Then have a scale portion of the score. Use some key dimensions- wing span, fuse length, stab span, root chord, tip chord, fuse height and width etc. to come up with a scale score. Maybe figure the percentages for these numbers, compared to the 3 view drawing to come up with a percentage figure for how close the plane is overall to scale. Then factor in a portion of the score as overall scale impression. Models often just "don't look right" if there are some problems in the design and execution, even when the outlines are exact. A factor here would give the builder and the judges some leeway to make to look good.

The goal would be to encourage more scale-looking planes with enough performance to be decent sport planes also.

youre kidding, right?

Talk to Mr. Rabe!

[photo not recovered: 3e69bb3870f12ad5.jpg]

"The great tragedy of Science -- the slaying of a beautiful hypothesis by an ugly truth." -Thomas Huxley

How about Billy Werages P-47 he won the worlds with?

And who would come in first Al Rabe or Ron Burns?

>And who would come in first Al Rabe or Ron Burns?

Ron B.
F4Fguy

Rabe,hands down! He can fly!

>Some of the posts on flying scale-like stunters got me to
>thinking.
>Why not an event for Scale stunters? Having tried, it's
>pretty obvious that a true scale plane will be too heavy to
>do the current pattern very well. Making a highly capable
>plane means turning it into a cariacature of scale. So the
>idea would be to use a modified pattern, with more emphasis
>on round maneuvers, perhaps a touch and go, etc. Make the
>flight pattern somewhere about half of the score.
>
>Then have a scale portion of the score. Use some key
>dimensions- wing span, fuse length, stab span, root chord,
>tip chord, fuse height and width etc. to come up with a
>scale score. Maybe figure the percentages for these
>numbers, compared to the 3 view drawing to come up with a
>percentage figure for how close the plane is overall to
>scale. Then factor in a portion of the score as overall
>scale impression. Models often just "don't look right" if
>there are some problems in the design and execution, even
>when the outlines are exact. A factor here would give the
>builder and the judges some leeway to make to look good.
>
>The goal would be to encourage more scale-looking planes
>with enough performance to be decent sport planes also.

Ron B.
F4Fguy

Phil:

while I applaud the sentiment,you're dead wrong as to capability. My first Wildcat weighed 60oz.,the second 64 both with ST 60s.The Macchis all weighed(with the exception of the last one which I refuse to discuss) between 58 and 70oz.,again with ST 60s. The present Zero is a little porky at 74oz.,but has a Surpass 70 in it.These are all VERY close to scale outline in all views,even crossection(the Wildcat is over 10" deep at the cockpit). All are between 650 and 740 sq.in..

The Wildcat,BT-13,and two of the Macchis have won hardware in sport scale competition,as well as PA. Admittedly this was local/regional competition, but I have the trophies.

The big problem with building scale stunt is the time invested, not the potential performance. Design time alone is more than total time in a "conventional" stunter.Also, Sparky is a piker at weight saving compared to that required to build a real scale stunter. Consider this:to be a scale P-47,as opposed to caricature scale,Werwage's fuselage would be roughly 1 1/2 times deeper and wider. It would also be longer by several inches. The surface area of the fuse would increase by about a factor of three,and that's only the fuse.Weight can get out of control very quickly unless there's some meticulous design planning. For example,I typically use 1/16",1/20" or two lams of 1/32"for molded shells,and depend on the section modulus for the necessary stiffness. This means great care in feeding loads into the monocoque. The basic rule is "use shape for strength,not thickness".Many of the things I routinely do to save weight are things the average guy is not willing to invest in, either in $ or learning curve. I made a "bunch" of wings before I could reliably do a carbon foam composite,but it saves some pork,is plenty strong, and is stiffer than any balsa wing,sheeted or otherwise, that I've ever done.

None of this is to denigrate the work of B.W. or Windy or anyone else.The results speak for themselves.These guys can design, build, and fly. My point is,rather,that you've really got to want to do it, to build true scale stunt.

Ron B.

PS: Phil;One of the PA trophies for the Wildcat was a second at your Mechanicburg contest many moons ago.

LAST EDITED ON Sep-28-04 AT 04:42 PM (CDT)
 
I wouldn't say I am dead wrong as to capability. As you say, if the plane is true scale, the fuse is pretty big and weight can build up rapidly. The average builder/flyer will have a hard time keeping the weight down to make the plane stuntable. Then add in that huge full span flaps are hardly scale. A nicely built, fairly light, Mustang would span ~54 in. at 1.5 in. scale and have about 500 squares. I'd expect it to come in around 50-55 oz. or so. It could do some nice round maneuvers, maybe a few sharp, not square, corners, and with retract gear and a throttle could be a pretty nifty sport/stunt plane.

Unfortunately, Bill Werwage's P-47 is exactly what I meant by a caricature scale. It is a very nice rendition of the typical scal stunt full stunter wrapped into a sorta scale looking fuselage. The kind of plane that might score 25-30% of scale.

Ron any idea what year you flew out here? I for the life of me can't remember it. Guess I'm getting old. What kind of a score did Reedy and I give you? It was probably us judging, since we did most of it back then.

LAST EDITED ON Sep-28-04 AT 09:30 PM (CDT)
 
Hi Phil,

Exactly my thoughts.

There is a huge difference between Billy's plane and anything that I would call 'scale'.

I too have been calling these planes 'caricatures' and I would include Joe Adamisco's "U2" and Spitfire, as well as Windy's Seafire and all of the planes have followed in his semi-scale series.

I would never take anything away from these fellows. It's just that what they're doing has little to do with with "Scale". By my measure, they would probably fall into the class of Fun-Scale planes.

The work that AL Rabe has done, is another thing entirely. If we are talking about powering-up to produce more planes like his, I'm all for it! Unfortunately, I'm not sure that I possess the engineering skills necessary to bring forth a successful design. I guess I'll always be relegated to be a follower but a happy one nonetheless!

In addition, I always question it when someone proposes a new and separate class of competition. Not would only you need enough competitors to create a viable competitive base but you would also be adding to a system that some people think is stretched a little thin already.

Of course, if it can be done, I'll probably try building a plane that would qualify.

Bigs,

I agree. It's a difference of approach. Bill or Windy or Paul take a highly successful stunt design (Junar or Patternmaster or Impact---whatever) and alter it to look scale. Some very loosely and some a bit closer, but all are competitive stunt planes in scale-like clothing. Semi-scale with the emphasis on "semi". Don't get me wrong, they look very cool and some project a very "scale"ish feeling. But they are generally far from scale.

The other approach is the one that Ron and Al take. You start with a scale plane and figure out the minimum changes you can get away with to have it fly comptitively. Planes like Ron's and Al's are not scale, but they are in the area. In some cases a very close relation. It's an amazing accomplishment. I would love to see Ron's Wildcat fly.

Excepted here is Paul's B-17. It's actually in the general neighborhood of scale (or at least presents that way) and was just impressive as heck. An interesting combination of both approaches.

>I wouldn't say I am dead wrong as to capability. As you
>say, if the plane is true scale, the fuse is pretty big and
>weight can build up rapidly. The average builder/flyer will
>have a hard time keeping the weight down to make the plane
>stuntable. Then add in that huge full span flaps are hardly
>scale. A nicely built, fairly light, Mustang would span ~54
>in. at 1.5 in. scale and have about 500 squares. I'd expect
>it to come in around 50-55 oz. or so. It could do some nice
>round maneuvers, maybe a few sharp, not square, corners, and
>with retract gear and a throttle could be a pretty nifty
>sport/stunt plane.
>
>Unfortunately, Bill Werwage's P-47 is exactly what I meant
>by a caricature scale. It is a very nice rendition of the
>typical scal stunt full stunter wrapped into a sorta scale
>looking fuselage. The kind of plane that might score 25-30%
>of scale.
>
>Ron any idea what year you flew out here? I for the life
>of me can't remember it. Guess I'm getting old. What kind
>of a score did Reedy and I give you? It was probably us
>judging, since we did most of it back then.

Ron B.
F4Fguy

Phil:

I'd have to dig it out to be sure,but around '88-'90.

I'm agreeing with you on Werwage's P-47, and certainly Windy's B-25, 26 and Typhoon. As for the Mustang, you're right,as far as you go,except I don't think there'd be any problem bringing it in at 45-50oz.. As to corner, ever see a Rabe mustang or Bearcat flown by a good pilot? The trick is to design so that it looks scale,even to an experienced eye, but is minimally modified to fly a decent pattern. For example, making the wing at only 10% larger scale (1.6 instead of 1.5)gives around 600". Obviously,the flaps need to be MUCH larger than scale,so you have to build very carefully to hide and minimise the hinge line(all mine are flush sealed).One of the things I've found you don't have to change,as a rule,is moments. With the right subject,if it was maneuverable at full scale,it'll be OK as a stunter.Naval aircraft usually translate well because carrier operation requires a lot of tail authority for carrier landing,so most have more than adequate tail volume. The basic design approach has to be to do what it takes to make a scale aircraft stuntable, NOT to wrap a sort of scale look around a Patternmaster.

And it's true the average builder won't invest the time to build,or to learn to build at the level required,let alone the design time. If they would,there wouldn't BE any BOM arguments or a need for ARFs.

Sorry,I'd promised myself I wouldn't go on a rant.

Hi Phil, The year was one in which we, Sondra and I, lived in Vermont and came down to the contest. Might have been 1988 or '89. I think Ron came up with Jimmy Paul who flew a Chipmonk without the cowel, as I recall. How about that Ron, was I close? Phil Spillman

>Hi Phil, The year was one in which we, Sondra and I, lived
>in Vermont and came down to the contest. Might have been
>1988 or '89. I think Ron came up with Jimmy Paul who flew a
>Chipmonk without the cowel, as I recall. How about that Ron,
>was I close? Phil Spillman

Ron B.
F4Fguy

That sounds about right.

LAST EDITED ON Sep-28-04 AT 07:35 PM (CDT)
 
>The big problem with building scale stunt is the time
>invested, not the potential performance. Design time alone
>is more than total time in a "conventional" stunter.Also,
>Sparky is a piker at weight saving compared to that required
>to build a real scale stunter. Consider this:to be a
>scale P-47,as opposed to caricature scale,Werwage's fuselage
>would be roughly 1 1/2 times deeper and wider. It would also
>be longer by several inches. The surface area of the fuse
>would increase by about a factor of three,and that's only
>the fuse.Weight can get out of control very quickly unless
>there's some meticulous design planning. For example,I
>typically use 1/16",1/20" or two lams of 1/32"for molded
>shells,and depend on the section modulus for the necessary
>stiffness. This means great care in feeding loads into the
>monocoque. The basic rule is "use shape for
>strength,not thickness".Many of the things I routinely do to
>save weight are things the average guy is not willing to
>invest in, either in $ or learning curve. I made a "bunch"
>of wings before I could reliably do a carbon foam
>composite,but it saves some pork,is plenty strong, and is
>stiffer than any balsa wing,sheeted or otherwise, that I've
>ever done.

A true scale stunter would be a brick. Considering that a real plane weighs in the tons. A real F14 ( the only plane I can speak about) weighs 23 tons a 1/8 scale plane would weigh 5750 LBS or 359,375 oz. so 1/16 size plane would weigh half of that. I don't really know what aprox scale we build in but I care not to go there.

Edit: Remember we don't have scale air and scale gravity.

Robert,

I think the consideration for weight is volume, which goes up by the cube, not linearly. So, take 23 tons = 46,000 lbs and divide that by (16 X 16 X 16) and you get about 11.25 pounds. Closer to the RC models of that size. Still, way too heavy for a CL stunter..

Right?

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"The man who complains about the way the ball bounces is likely the one who dropped it." -Lou Holtz

>Robert,
>
>I think the consideration for weight is volume, which goes
>up by the cube, not linearly. So, take 23 tons = 46,000 lbs
>and divide that by (16 X 16 X 16) and you get about 11.25
>pounds. Closer to the RC models of that size. Still, way too
>heavy for a CL stunter..
>
>Right?

I was just guessing. So I guess thats right. Now what do we do about scale air and gravity? But eaven at that its still way to heavey for my likes.

>Robert,
>
>I think the consideration for weight is volume, which goes
>up by the cube, not linearly. So, take 23 tons = 46,000 lbs
>and divide that by (16 X 16 X 16) and you get about 11.25
>pounds. Closer to the RC models of that size. Still, way too
>heavy for a CL stunter..
>
>Right?
>
>[photo not recovered: 3e69bb3870f12ad5.jpg]
>
>"The man who complains about the way the ball bounces is
>likely the one who dropped it." -Lou Holtz

Ron B.
F4Fguy

We build to scale outline not scale structure or loading. Check the weights on Al Rabe's or my airplanes,you'll find they're comparable to other,similarly sized stunters.

A true scale stunter would be a brick. Considering that a
>real plane weighs in the tons. A real F14 ( the only plane I
>can speak about) weighs 23 tons a 1/8 scale plane would
>weigh 5750 LBS or 359,375 oz. so 1/16 size plane would weigh
>half of that. I don't really know what aprox scale we build
>in but I care not to go there.
>
>Edit: Remember we don't have scale air and scale gravity.

Ron B.
F4Fguy

+/- 1/7 scale, 685 sq.in., 64 oz.

Phil,
They already have the event your talking about. It`s called scale.And they have a easy pattern for the scale planes to fly.

I flew one at the Tulsa contest Sunday. A photo is in the Tulsa contest thread. This one is not a caricature!

Don so graciously let me fly his Sterman several times and it flys good and is very cool and it worth lots of ooh ah points. It is a truly a work of art.
Joe Gilbert

>Don so graciously let me fly his Sterman several times and
>it flys good and is very cool and it worth lots of ooh ah
>points. It is a truly a work of art.
> Joe Gilbert

Ron B.
F4Fguy

I rest my case.

LAST EDITED ON Sep-29-04 AT 11:30 AM (CDT)
 
>Some of the posts on flying scale-like stunters got me to
>thinking.
>Why not an event for Scale stunters? Having tried, it's
>pretty obvious that a true scale plane will be too heavy to
>do the current pattern very well. Making a highly capable
>plane means turning it into a cariacature of scale.
----------------------------^^^^^^^^^^^^^^^

Maybe you should introduce yourself to Al Rabe and Ron Burn.

Where do you get this stuff?

BLACK HAWK
At Black Hawk Models we are currently working on a line of models that might fill the bill for scale stunt. We have the scale part and are working on the stunt trials. I do not expect them to perform with a full stunt model but we are shooting at the stunt pattern. The models that we are working on are in the .15 to.25 engine size. We are testing two differant airfoils and tring to keep construction simple and fast. There is alot of head scratching and tears on the drawing table, but the test planes are about to take shape.
Larry