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Author Topic: engine size versus wingspan  (Read 1024 times)
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ksn3n3
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« on: November 25, 2016, 12:52:22 PM »

I'm getting ready to order some plans to build a few models for some vintage engines that I have and wondering what are some good rules of thumb for engine size versus wingspan for C/L Scale.  I realize thats a bit of a loaded question amd very subjective.  Im looking for a scale model that flies at 'scale' looking speeds., i.e not so underpowered that it is staggering around the circle, and npt so overpowered that I can do all acrobatics in the book.  Something inbetween. Im looking to use a McCoy.35, Supertiger .36, and K&B .40 and building several biplanes and also a monoplane if that makes any difference.  Looking on line at both kits and plans engine sizes seem to be all over the place and inconclusive.  Any thoughts appreciated.
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packardpursuit
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« Reply #1 on: January 15, 2017, 12:18:19 PM »

I think you have tumbled to one of the real unappreciated false perceptions faced by modelers. That is the ASSUMPTION that there is or must be a correlation of engine size to wingspan! It is a pervasive rule of thumb that has been widely promoted, but is patently false.

It goes directly to how we perceive an aircraft model's (real aircraft too!) size. Simplistically we refere to it's wing span as it's "size" but that soon runs into stark and often conflicting physical realities. For example a Monocoupe 90a and Beechcraft model 17 are two classics aircraft of the 1930s. They share  the exact same span(32 ft) but the latter is so much  larger in every other way. If you were modeling both, in same scale, their structure and power requirements would be quite different. A situation existing the full size counterparts, for the exact same reasons.
 
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ghostler
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« Reply #2 on: January 16, 2017, 09:38:16 AM »

ksn3n3, if you really want to know, if I were you, I'd get a simpler profile and fly it first. That will give you an idea of what you really want. The McCoy .35 Red Head works fine on the profile 42" (1067mm) wingspan 400 in2 (25.8 dm2) wing area Sterling Kit S-1 Ringmaster and similarly proportioned Top Flite Flite Streak. Fly on 60' (18m) lines. Adding 12 oz. to a pint of Castor oil to a gallon of standard 5% - 15% nitro RC fuel will up oil sufficiently to properly lubricate and protect these older engines. Running on a rich 4 cycle breaking into 2 cycle in stunts will give you roughly 5 second laps on 10x5, 10x6 props, which is decent for all the stunts but not too fast or slow, which is what you want. 3 to 4 oz. tank (RC clunk tanks are okay) will give you 4 to 5 minutes flight time.

Then, you will have an idea of what size plane you want based on your experience. Otherwise, it is all academic. The more modern .20 to .25 Schneurle ported engines are roughly the power equivalent to the McCoy .35. Hence this may cause some confusion in engines recommended for a particular plane.

http://www.clstunt.com/ (Stuka Stunt), http://stunthanger.com/ (Stunt Hangar), http://www.brotherhoodofthering.info/ (Brotherhood of the Ring) are a few control line forums where you can get additional inputs. Good luck.
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George Hostler
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« Reply #3 on: January 16, 2017, 01:32:19 PM »

It goes directly to how we perceive an aircraft model's (real aircraft too!) size. Simplistically we refere to it's wing span as it's "size" but that soon runs into stark and often conflicting physical realities. For example a Monocoupe 90a and Beechcraft model 17 are two classics aircraft of the 1930s. They share  the exact same span(32 ft) but the latter is so much  larger in every other way. If you were modeling both, in same scale, their structure and power requirements would be quite different. A situation existing the full size counterparts, for the exact same reasons.

That goes for the real airplanes, too -- they both had radials, but the one in the Beechcraft was a honkin' big one compared to the one in the Monocoupe.
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TimWescott
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« Reply #4 on: January 16, 2017, 01:42:00 PM »

Without making a huge set of rules involving weight, span, area, draggy bits (struts, wires, etc.) and whatnot, I don't think there's a good way to do this.

One thing you CAN do is to look for build articles for similar planes.  I.e., all monoplane warbirds are going to be about the same, a Piper Cub and a Taylorcraft are going to be about the same, one between-wars fighter biplane is like another, etc.  So if you want to do a Dewoitine D.500 (which is one of the planes that fascinate me) then you can figure that it's going to fly an awfully lot like a Spit only with some extra drag, and go from there.

Model design (and full-scale design, for that matter) really falls into having a "works every time" formula that always generates the same basic plane, shamelessly copying someone else's engineering while just changing the aesthetics, or doing some complete experiment and going through numerous revisions before you hit a successful combination.  Since there's a lot of similar airplanes out there, there's a lot of opportunities to find stuff to borrow.

(And please, please, don't make a 48" span Piper Cub with a 40 in it.  A Cub should not fly like a P-51).
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LOUCRANE
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« Reply #5 on: January 24, 2017, 07:35:12 PM »

ksn3n3 (did I get that right?)

Most modern (and older) engines used for scale flying have throttles. That alone offsets the "ultimate power" problem: you can throttle back if you go so fast you are uncomfortable. As mentioned above, "realism in flight" is a factor if you are being judged.

A "Piper Cub" type model should look slower than a Spitfire of Mustang. And vice versa.

Scale models, in my opinion, should be heavier than stunt or other sport types. When you slow them down, you need more Angle of Attack (nose high flying attitude.) A typically over-powered CL model doesn't do that, nor does it land at reduced throttle. "Realism" again...

Too much power, as I said, is not really a problem if you can throttle back. Too little IS a definite problem; if you get into a bind punching throttle may help you recover.

I have other ideas about "realism" for CL scale models... Flying 'flat' in a circle that would require significant bank for a "real" airplane? Hmmm... The associated skills and abilities needed in CL Scale flying are charm enough - the other stuff is secondary. (IMO.)
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packardpursuit
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« Reply #6 on: January 27, 2017, 12:29:57 PM »

"charm enough"
I like that!

IMHO- biggest detriment in CL scale flight is generally too much speed for the prototype modeled. Lighter wing loadings allow for slower and SAFER speeds, however,  CL scale designs and plans are not known for promoting lighter wing loadings. Simply throttling back an overloaded airframe is not always practical, either  aerodynamically or esthetically.

 I think it telling that the traditional view of over coming too heavy a model is to simply add more power. Something the model engine industry has promoted  and gladly provided, for years.

Speaking of industry, How many of us old timers still think  .049 power is adequately serviced with a model airframe in 16"-18" wingspan range? Outfits like Scientific pretty much drummed that into our collective consciousness. Never mind it is simply not specifically true. I tend to think the 18"span norm stems more from the fact  half a stock sheet of 1/8" or 1/4" x 3" balsa is 18".
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packardpursuit
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« Reply #7 on: February 05, 2017, 11:34:38 AM »

I've always thought, If its enough power for RC it's about right for CL Scale. I seem to recall a couple of VK 1/6 RC scale WWI kits being flown as CL scale and using .60's for power. Personally, I think a good .40 in a VK Nieuport   COULD BE an excellent match, on 60 ft lines.
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ghostler
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« Reply #8 on: February 05, 2017, 07:14:19 PM »

Back in the 1950's, there were a number of free flights that were also for control line. The 30" (760mm) Goldberg Ranger 30 cabin used a Cox .020 Pee Wee for FF and .049 Babe Bee or Golden Bee for CL. http://www.outerzone.co.uk/plan_details.asp?ID=3830 You'll see photos of my Ranger 30 there as an FF. Berkeley scale kits had dual or triple designations, too. Some of those later became the Sig Craftsman series.

On all these in general, the engines used for CL were smaller than normally we are accustom to. There is a drawback, which is wind penetration. Calm weather permitting they did fine.

Regarding Scientific standardizing 18" (460mm) as the standard wing span, a half sheet of 36" balsa, in the 1950's and 1960's, kits were very cost competitive. These kits were sold in the thousands then. The market targeted school age boys. Older boys nearing adulthood and adults of course would opt for the larger and more expensive aircraft. The stand-off scale full fuselage looks of the Scientifics, with real decals and clear windows and canopies were very appealing. I was very excited when I got a Scientific Hellcat for my 11th Birthday. Kits then were under a couple bucks each. Also, you must remember that many of these kits were designed prior to the Cox more power .049 engines. The less powerful .049 OK Cubs are shown on many Scientific 1/2-A CL's.

Back then, there wasn't the stigma of a noisy unmuffled small engine in a school or public park like there is now. It started IMO shortly after the Vietnam War. People prior looked at it as healthy noise and that a child was occupied and staying out of trouble.

The RTF CL's IMO are also responsible for standardizing the 18" to 21" wingspans.

Although a novelty, personally I'm not into the so called scale flight speeds in control line. If I see a Fairchild Ranger cabin doing 5 second laps on 60 foot lines, even engaging a loop or inverted flight, I think it amazing and enjoyable. Control line is different enough that the fact it flies and flies well is enough to suit me.
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George Hostler
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« Reply #9 on: September 19, 2017, 02:17:55 AM »

As usual, I've been lurking here, but I've got to put my oar in.
First, it's not about span.
Second, its not about power.
Third, It is about loading; area, power, and my favorite, cubic wing loading.*(Google it)
For example, if you were to build a seven foot span Mustang at an all up weight of 7oz.you'd have little trouble flying it on an average .09engine, or even a reasonably healthy .049. It would be slow, but it wouldn't have to be fast to develop the lift necessary to fly well. A 70oz. model of the same aircraft would  need at least a .60 to .90 to be fast enough to develop the lift to fly the heavier airplane.
Obviously the above example is extreme,and probably impossible, but you get the idea.
A real example is a J-3 Cub 65hp that I designed as a free flight power scale model and converted to throttle control UC. Six foot span, about 4.5 pounds, powered by a Tigre .19 with throttle. Absolutely the most fun I've ever had with a model airplane!! On 70' .012 lines it turned a lap of nearly 10 seconds at full throttle, and takeoff was nearly a lap from start of roll to tail-up to breaking ground. Realistic stalls could be flown by climbing to 45 Deg.,pulling the throttle back, and waiting for the nose to drop. Landing was also per full scale, set a glide path, pull back the stick to slow to threshhold, pull  back to slow even more, then, just at touch down ,close the throttle to idle or just above, set it on all three and roll out.
I write the above not to blow my own horn but to illustrate what's possible.
Obviously if you want to do aerobatics, the power to weight ratio has to go up, or the weight to wing area has to go down. even that depends on the performance your looking for. If the goal is the full CL pattern your  going to need much lower loading than for the occaisional loop or wingover.
As a final note, and I emphisise that this is a personal opinion, scale airplanes should fly as closely as possible to their full scale prototypes in terms of performance envelope. If anything is to be ignored, it should be top speed,not takeoff, landing, or maneuvering ability.

MOHO,

 Ron Burn - F4FGuy




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Jack Plane
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« Reply #10 on: September 20, 2017, 03:42:06 AM »

I agree very largely with F4FGuy.

I have only dim memories of flying CL Stunt, but its certainly all to do with wing-loading - and IMO a reasonably convincing 'scale speed'.

An example from RC of choosing suitable motor sizes:  For aerobatics I usually fly a 59" span low-winger weighing 6lbs with a 70 four-stroke giving a rated max thrust of 800 watts - which equates to 133 W/lb.  I'm now building a slightly larger 63" but much lighter 4lb low-winger also for sports aerobatics, and am fitting a 35 two-stroke with a thrust of 660 watts - equating to 165 W/lb.  Clearly the larger, lighter model will suffer more from drag, but the higher thrust/weight ratio should overcome this.  For scale, a weedy 30 four-stroke is all that's needed for a 40" 1930s biplane (albeit with a wing area greater than the two aerobatic types above) in order to achieve realistic flying speeds.

In FF rubber scale, overall size, configuration and environment are also factors.  For example a sleek, small (20") low-wing monoplane outdoors penetrates nicely with a wing-loading of 0.7g/sq in, whereas a larger (30") biplane in the same environment can get away with a heavier loading of 1g/sq in.

Indoors however, I'll be aiming for about 0.4g/sq in for a 20" high-wing cabin model (with less power needed and therefore a weaker, lighter rubber motor), maybe up to 0.5g/sq in for a 16" draggy biplane (with a bit more grunt from a thicker motor).

For indoor Peanut scale (13" span) rubber (where duration wins points, unlike the larger scale classes where flight realism is the key), the wing-loading to aim for would be about 0.25-0.3g/sq in!

This should all translate into CL with its not dissimilar variables.
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ghostler
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« Reply #11 on: September 20, 2017, 01:06:15 PM »

Appreciate all the inputs, seems these days we don't see much attempt at scale speeds in CL. You've perked my curiosity, I ran some numbers, here's what I found out.

Grumman F6F Hellcat has a 43 foot wingspan. Modeled in 1/12th would be a 43 inch wingspan (close to my Sterling 42 inch span profile Hellcat.) On 60 foot lines and hand extended adds about another 3 feet from center of chest to handle. 5 second laps give 54 mph. The F6F had a top speed of 380 mph. Then standard CL flight timing of 5 second laps for AMA stunt pattern gives a scale speed of 648 mph. To maintain true scale, speed would be 32 mph with 8.5 second laps.

Piper J3 Cub has a 35 foot wingspan. Modeled in 1/8th scale would be a 55 inch wingspan. Real speed at 85 mph, with same length 60 foot lines, true scale speed would be 11 mph with 23 second laps.

Besides effects of prevalent wind during flight which must be overcome, another is maintaining sufficient line tension throughout the flight envelope for successful control. I've attached two screen captures of centripetal force (i.e. line tension given the weight of the model, line length and speed) calculations from http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html.

A 2 lb. model on 60 foot lines exerts 6.2 lb. line tension. Overhead vertical flight would still give a 4.2 lb. line tension. At F6F scale speed 32 mph with 8.5 second laps, it would exert a 2.2 lb. line tension with only a 0.2 lb. overhead line tension in calm weather. Thus, scale "combat" flights would not be realistic except may be indoors.

The problem is exasperated further with the slower Cub flights. Horizontal flight in calm weather might be possible, but definitely no stunting. Let's say one built their model very light to give a 2 lb. finished weight. Then line tension at 11 mph scale speed with 23 second laps. Then line tension is only 0.27 lbs. You'd have to fly in 0 wind (indoors) and could not do anything but level flight at arm height. Stunts are definitely out of the question.

It's been a while since my fluid dynamics course that I took 30 years ago. Wind tunnel models scale speeds are based on Reynolds numbers, which are considerably higher than "scale" speed. This is necessary to provide realistic simulations of the full scale plane. Ships on the other hand use true scale speed, because water wave modeling motion through water is best approximated by scale speeds.

This is probably accounts for why except in rare cases scale speeds have not been emphasized in CL flight, IMO.
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George Hostler
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« Reply #12 on: September 28, 2017, 11:53:30 PM »

George,

A couple of points; first, line tension, as long as you maintain some, is not a problem, and you (if you know your airplane)can always increase it by a simple arm pull, or a step back.

Second and more IMO more important; theappearance  of scale flight is what's really required. This goes far beyond speeds. Aircraft attitude is key here. Too heavy and you have to maintain too high an AOA to slow as far as realism demands.
This is especially evident on landing. With the heavy plane you have to fly a higher AOA or higher speed to maintain a realistic glide slope, drop the  flaps and you have to increase AOA even more. Even a two wheel landing has to be at higher than realistic speeds, a three point touchdown is next to impossible unless you fly the airplane into the ground In the three point attitude, instead of setting an AOA just above stall, coming over the threshold at that attitude,then pulling back power 'til stall and simultaneous touchdown.
The above simply cannot be done with a too heavy A.C.

Ron Burn  (F4FGuy)
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« Reply #13 on: September 30, 2017, 02:12:11 AM »

For a model flying at "true scale" speeds, couldn't you make up for it somewhat with shorter lines?  On 30 foot lines, a model ought to pull twice as hard.

BTW, a 2 lb, 55 inch Cub isn't likely to fly at 11 mph. It probably needs somewhere over 16 mph. It would probably need to be under a pound. You'd probably need to fly it on 15 foot lines (!) or something.

Some years ago, I think in Model Aviation, there was an article about a very light Cl model that was supposed to get the turning radius down near what was specified in the rules. It had a 4 foot wingspan with a 1/2A(!) engine, canted a ridiculous angle  outward for line tension:
http://www.modelaircraft.org/plans/images/1985/480.jpg

------------
Wingspan, relative to weight, will be a big part of the power requirement if you want to fly relatively slowly. All else being equal, more is usually better. Up to a point, anyway. As I recall, Mark Drela and his students came up with what looked like a 3 meter RC glider, except for the airfoil. I think it was supposed to require 11 watts of power in level flight!
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ghostler
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« Reply #14 on: September 30, 2017, 10:29:06 AM »

For a model flying at "true scale" speeds, couldn't you make up for it somewhat with shorter lines?  On 30 foot lines, a model ought to pull twice as hard. BTW, a 2 lb, 55 inch Cub isn't likely to fly at 11 mph. It probably needs somewhere over 16 mph. It would probably need to be under a pound. You'd probably need to fly it on 15 foot lines (!) or something. Some years ago, I think in Model Aviation, there was an article about a very light Cl model that was supposed to get the turning radius down near what was specified in the rules. It had a 4 foot wingspan with a 1/2A(!) engine, canted a ridiculous angle  outward for line tension:

http://www.modelaircraft.org/plans/images/1985/480.jpg

Wingspan, relative to weight, will be a big part of the power requirement if you want to fly relatively slowly. All else being equal, more is usually better. Up to a point, anyway. As I recall, Mark Drela and his students came up with what looked like a 3 meter RC glider, except for the airfoil. I think it was supposed to require 11 watts of power in level flight!

11 Watts is 0.015 HP. A Cox Babe Bee is 0.056 HP http://sceptreflight.com/Model%20Engine%20Tests/Cox%20Babe%20Bee%20&%20Golden%20Bee.html.

The dude's .049 C/L plane is nice work. I noticed he flies it clockwise to take advantage of the engine torque to provide additional line tension. Standard C/L flight is counterclockwise.

A 1 lb. model at 55" wingspan will not be too far off from a rubber powered stick build tissue covered aircraft, by the time strength is added to contain the engine, weight of engine, fuel tank and control system, etc. My 36" Sterling R/C Minnie Mambo cabin with .049 is a touch less than 1 lb., flying speed is around 35 mph in level flight. A standard .40 size R/C plane is around 4 lbs., hence why I came up with the hypothetical 2 lbs., which is about what my 42" Sterling Ringmaster C/L stunt with McCoy .35 Red Head weighs.

I think there are practical limits to scale flight overall. I think a better term would be realistic flight, a speed that is perceived to be scale like, especially when it comes to slower real aircraft. 35 mph seem realistic enough. All the designs of scale C/L aircraft are constructed heavier and use larger engines to provide overall standard C/L circle speeds.

Personally, flying outdoors in the New Mexico High Plains desert bordering Texas Panhandle with few trees, we rarely have calm weather. At least once a month we get winds to 50 mph. A good day has winds of 20 mph or less, which occurs about every four days when winds are changing direction. When it gets about 22 mph, then take into account gusts, I call it a day and wait for another. The small half-A reedies with their slower flying speeds are impractical, both R/C and C/L.

Hence overall, this is perhaps why we don't see much emphasis for C/L and R/C aircraft to achieve scale speeds unless may be they are jets.
engine size versus wingspan
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« Reply #15 on: September 30, 2017, 03:36:29 PM »

George,

I have to disagree strongly . Increased span alone is a detriment not an advantage. For the same area, the chord goes down, decreasing the Rn which is already compromised by scale effect.
No matter how you slice it, loading is the only way to get there. The bigger the model airplane for it's weight, or the lighter for it's size, the more realistic the flight envelope.
Also, offsets should be minimal. Line tension increases when the AC is going in the direction of lowest drag, i.e.tangent to or following the curve of the circle. I have ,for years, setup all my airplanes with 0 degrees in engine and rudder, and with line rake set to as near as possible to the curvature of the line entry to the tip.

Ron Burn (F4FGuy)
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« Reply #16 on: October 02, 2017, 03:56:42 AM »

George and F4 -
Excellent points all around. I never learned to speak or think metric (going on 78 years - we spoke foot/pound/second then.)

Given that we must fly our models in a way that is possible, or they won't fly, consider this: The 'impression' of speed is more useful than the actual timed speeds. Say, what...?

A J-3 Cub should 'look' slow; a P-38 should 'look' faster. J-3s wallow a bit on landing approach. P-38s -flown reasonably- do not.

If you want "scale appearing speed" consider this example: I  see occasional C-17 transports land at a nearby Army airfield. They look like they are barely moving on approach. Don't know their length of fuselage, offhand, but for realism the same number of fuselage lengths per second might be a way to judge "realistic" flight speed. Say they are six or seven times as long as a J-3 or 140... To fly the same actual airspeed over the ground would require the lightplane to go six or seven times as fast, no? To fly the same fuselage lengths per second, they'd need to move six or seven times slower. If the C-17 does 120 mph on final to touchdown, a J-3 model can't "look" the same speed at more than 15 or 18 mph. Wanna try that? Me neither.

We can't do it, any way you look at it. We can, however, fly a CL scale lightplane on the slow edge of rock-solid forward flight, to look slow. Even if the plane-lengths-per-second is many times what a C-17 performs. The heavy metal plows through by sheer mass, with some, not much, wobbling due to ambient air (and pilot actions?)

It's the impression of fast or slow that contributes, IMHO. "Realism" is subjective. Relative impressions of fast or slow are better than mathematically calculated actual airspeed differences, and make it possible to fly our models so they can survive. IM(not so)HO.
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« Reply #17 on: October 11, 2017, 01:48:38 AM »

Lou,

I agree that appearance  of scale speed is paramount. But, I have to disagree, when you say "it can't be done".  Ive done it. It's not hard. A little difficult to fly in winds more than 10 mph, but not impossible.
My reply #9 above, was actual experience. The J3 was a free flight power model converted to control line with throttle control. The whole Idea was to duplicate the flight behavior of a Cub in U.C. form. The only thing I could never overcome was the image of a full scale J3 flying unbanked 870 ft. circles.

Keep a handle on it,

Ron Burn (F4FGuy)
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« Reply #18 on: October 14, 2017, 03:43:41 PM »

Well done!

Have you seen that UTube of a model passenger jet - Boeing 73something or comparable Airbus - flown at nearly accurate speeds in plane-lengths-per second? Turns out the model was inflatable, likely with helium. Ballasted to vey slight negative buoyancy... Video was indoors, of course, RC, of course...

At camera distance, quite convincing. Spooky even. Final scenes, asir, were of a spectator horrified to watch the deflating model after the flight.

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« Reply #19 on: November 02, 2017, 12:58:27 PM »

Boy, I go away for a while and you guys come up with all sorts of provocative thought and discussion!

I was thinking about that very same type of low weight, large area .049 powered stunter., flown on 60ft lines. The one I recall had its engine in outboard LE with considerable thrust off set?

I've always wondered about the effect some claim as an advantage by flying clockwise, when using engines turning counter clockwise.  Isn't any torque mitigation eliminated once the model goes 90 deg elevation, and goes fully opposite when inverted??? I would think so. It would only help on take offs and landings. On other hand, could be a distinct advantage for non-invertible scale subjects.

 I think the "so many fuselage lengths per second" is a valid but somewhat cumbersome analogy of scale speed. I' find myself wondering at what speeds the wings go, etc?   Roll Eyes

I also have to agree that physics dictate the speed of our models, more than anything else. However achieving scale like flight is very attainable, if we pay attention.

Finally, I'm astonished at someone reporting success with no engine  or rudder offset, and only raking the lead outs to estimate the curve of lines in flight! It's positively in your face, against established thinking. Grin Grin I love it and hope to try it out soon. I suppose I should say that I'm the kind of guy that uses no offset thrust, and only a modicum of rudder offset. In real world aviation, opposite rudder is the only effective counter to torque, ESPECIALY at take of. I also have  not put ANY outboard tip wt on a CL model.  With or without tip weight made no discernable flight difference to me.

I appreciate the back and fourth. It sure stimulates the gray matter.
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« Reply #20 on: November 29, 2017, 05:59:02 PM »

Read the above thread with some amusement.    And yess it's an older thread, likely gone and hopefully forgotten
 Still I'm amazed :  No Off set.. .No rudder.. Sketchy rake..  then  Fly slow and it'll be OK ?   Not on MY planet.
 Reads as the voice of complete inexperience imo.
 Too light Cl planes don't  fly well and certainly not for long.  Neither do underpowered ones.
 Line tension is Mandatory  and more is always better.  Even for low slow and flat flight, let alone mild aerobatics or let alone Stunt or Gawd forbid Combat.
Fast combat line pull is in the 12/15 Lb range..  1/2 a combat line (52 ft standard) pull is in ounces.. 
consequently  flight performance in even light wind /heavy breeze.. is Only for very experienced flyers.
 Stepping back as a routine  method to maintain line tension .. Seriously?   
I regard  that as a Last ditch try to save the plane .. not  an SOP
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« Reply #21 on: November 30, 2017, 06:14:37 AM »

Fred,

The voice of complete inexperience here. I'm new to this planet

Please tell me how to get more experience.

I've been building and flying model aircraft since I was five years old ( 79 years ago). My first contest was at the age of twelve flying "A"speed. My first NATs was  at Willow Grove NAS in 1953. My last NATs was Lubbock TX some twenty + yrs ago. I've always designed all my competition aircraft myself. I'm not a champion pilot, I flew advanced stunt throughout my competition years and * always finished well but out of the money at NATs level * but usually placed locally or regionally. Basically I don't like to practice.
         **Except in 1988 -Look it up

I've attached some pics of my stunt aircraft. Please note, they are nearly exact scale outline. All have placed well (usually 2nd or 3rd) in sport scale as well as stunt.

I apologise if the above sounds a bit snarky, but I have done exactly what I described. All of these AC are designed for a a quick changeover to throttle control and normal flap operation. They are large models, the Zero and Macchi are both  735 sq.in.,  the F4F is 675sq. in., and the BT-13 is smallest at 550sq. in. The Macchi is heaviest at 70oz., the BT-13 lightest at 55oz.  All are to the same scale of 1:7. I have made one bow to convention, all have " Rabe " rudders.

Ron Burn (F4FGuy)




Attached files Thumbnail(s):
Re: engine size versus wingspan
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« Reply #22 on: December 01, 2017, 07:24:56 PM »


 All:Including Fred,

 In my last post, I neglected to include some of my 1/2 A Models,built only for fun, and my practice airplane, a profile with an OS 35fp.

The Nieuport 28 and Albatross DV were used in combat, in a form invented by John Hunton, where we flew four to six in a match, all in the air at once, Allied and Central Powers. The idea was to ram, last in the air won. 

The "Spit" was designed for a kids class I taught for our club Eric Rule cut the kits for me. Over a hundred were built by the kids. All flew successfully.

The "Lil Zero" built to see if I could build light enough for 1/2 A stunt. It was a little "porky" at 10+oz. on 128 sq. in.,but would do the pattern if flown fast enough(four second laps).

I built the profile as a "disposable" practice AC. It worked very well for several years until I "dorked" it. It was designed to duplicate the flight characteristics of my usual "Scale Stunt" AC.

   Ron Burn (F4FGuy)





Attached files Thumbnail(s):
Re: engine size versus wingspan
Re: engine size versus wingspan
Re: engine size versus wingspan
Re: engine size versus wingspan
Re: engine size versus wingspan
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faif2d
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« Reply #23 on: December 02, 2017, 07:14:11 PM »

I saw the Wildcat at the nats in Chicago?  It may have been in Sagine, Tx don't recall.  I thought it was a perfectly executed model and was very disappointed when they placed it in the back row of the appearance judging.  It was wildly different than the polished ships but I thought more impressive than the rest.  Of course I have always wanted to do a plane like the Ridiculous and then using photo or video evidence to protest every one of the other flights because I would be able to do a 5 ft R corner and no one else would even come close.  But then I like to engage in fights with windmills too!
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« Reply #24 on: December 03, 2017, 06:01:15 PM »

FIAF2D,

Thanks.

It was at the Tidewater NATs in '88. I also flew it at Westchester earlier, in sport scale,as it was brand new and hadn't been flown enough to be used as my primary stunt AC.

Ron Burn (F4FGuy)
Attached files Thumbnail(s):
Re: engine size versus wingspan
Re: engine size versus wingspan
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