Author Topic: What I like to do when I'm bored (a new sketch) (Read 18733 times)

Matt Colan · « **on:** July 29, 2009, 08:07:11 AM »

When I'm bored, I like to draw up stunters, for the heck of it. Who knows if I'll ever build the 20 or so planes I drew up. This one I think is my favorite, in terms of looks, very classic like. This plane has a 9 1/2 inch nose, and a 15 1/2 inch tail. The wing has a 10 inch chord 2 1/4 inches thick. If I built this plane, it would have a wingspan somewhere around 55-57 inches. If I built it, what should I name it?

What does everybody think of this plane?

Edit for typo

John Miller · « **Reply #1 on:** July 29, 2009, 08:40:30 AM »

Nice looking design Matt. It has the it factor.

I think drawing stunt planes, well, let's make that just planes, is a fun and rewarding past time. You are following in a great modeling tradition.

There're some items to keep in mind when designing. Learn them early, and most of your designs will fly decently, with some flying brilliantly.

Gear placement and design will help you get high points for take offs and landings.

Learning about lift and drag will help you design wings and structures that make the best use of the power available.

Moments give you the power in the control system to control the beast.

Control system geometry work hand in hand with the moments.

If you can find a copy of Simmons Model Aircraft Aerodynamics, ISB 1-85486-121-2, it will help you learn a lot about the whys and wherefores of desining model aircraft.

Keep up the great work Matt, You remind me and many others of ourselves , "back in the day".

Matt Colan · « **Reply #2 on:** July 29, 2009, 09:27:03 AM »

Thanks John. I know what you mean about gear placement. Asthetically I don't like narrow landing gear, I like a wide stance for both performance and looks. I read Windy's article in CLW about designing and concept sketches, and he said not to stray too far from existing designs, otherwise your plane might not perform well.

Now before I decide to draw a plane in full scale, I make a 1/4 scale drawing on graph paper, I think it is much easier doing it that way, rather drawing blindly.

Dennis Adamisin · « **Reply #3 on:** July 29, 2009, 10:28:23 AM »

I don't go thru and make full drawings but I do a lot of freehand sketchs on grid paper. You like the clasics - kewl! Personally I do not like classics, so I gave myself an "assignment" to try to design a classic shape that I liked: started with a basic classic shape, changed this and that, added or took away something else Then while building I got a couple other ideas and added them in - all ended up being the Mythbuster you saw in PA. Want to go back and build something more like the original sketch some day...

For the excercise: try designing in other generes; jets, modern, upright engine, 'lectric (gasp!) anything that forces you to look at different aesthetics and get familiar with them.

I like looking at what's been published. Example: Dave Gierke's Novi, Novi 3 and All American Eagle all have a lot of similar design elements in them. I saw all 3 of the originals when Dave was campaigning them. For me the Novi 3 absolutely blows the others away. That's odd because the AAE is very similar to the N3. Principle difference is in the canopy and the tail cone - but AAE seems to lose something. Thus, sometimes I do my interpretation of other peoples designs; pick and choose among features I like, and try re-combining them - I use this exercise as a thought starter. Dave did something else I like; for Novi 4 he broke with all the predecessors - the only piece he kept was the cowl - cuz he had a fiberglass mold! Yet the N4 still has Daves "personailty" in it, and the N4 strongly influenced countless designs since.

Was looking at the Sting Ray article last nite. I like everything about it except the wing tips - I would have to reverse the tips if I built one - but then it would not be a Sting Ray anymore! OK if its not truly a Sting Ray then what OTHER changes would I make; get out the sketchpad. We built several birds that used Mirage 3 airfoils, but NONE of ours had those gawd-awfull wingtips. Speaking of wnigtips, don't get me started on Airon, Apteriyx, Avanti, Barracuda, Cardinal, LaDonna, USA-1, etc. I have a Cardinal kit, the only reason I might build it is to FIX THOSE DARNED WINGTIPS!!! Acutally if I built it I would reverse all the tips and the fin thus improving the aesthetics by maybe 1000% - and call it "LANIDRAC"

Try sketching features: cowls with scoops (!!!) or without, cheek cowls, radial cowls, upright with speed bonnet, different wing shapes, different wing tips (did I mention I HATE swept forward tips?), different canopies, and all kind of different fins Fins FINS!!!! Oh yeah, don't forget V-tails, droop tails, high tails, low tails, twin tails, stinger tails - you get the idea.

For a real challenge try taking stunt "numbers" and try designing semi-scale around them. It really compells you interpret the personality of the the prototype, and translate it into CLPA-friendly package...

All you need lots of paper, PENCILS, and a big eraser.

What's in a name? All I can say is that it will come to you. I have started some sketches based on a possible name. For example, I took the word "Extreme" and started sketching an extreme stunter. Along the way it became the "No Prisoners" I could show you the sketches - but then I'd have to shoot you...

John Miller · « **Reply #4 on:** July 29, 2009, 10:47:45 AM »

Quote from: Matt Colan on July 29, 2009, 09:27:03 AM

Thanks John. I know what you mean about gear placement. Asthetically I don't like narrow landing gear, I like a wide stance for both performance and looks. I read Windy's article in CLW about designing and concept sketches, and he said not to stray too far from existing designs, otherwise your plane might not perform well.

Now before I decide to draw a plane in full scale, I make a 1/4 scale drawing on graph paper, I think it is much easier doing it that way, rather drawing blindly.

Dennis is one of those gifted designers who starts with a concept sketch and goes from there. I personally find it a great way to go. When I was a young man, I made concept designs of planes and cars, my two favorite subjects prior to girls.

I was able to take advantage of high school drafting classes, and learned to move my concept drawings into that genre.

Today, I make my concept drawings on the computer.

Whatever form you use, get your ideas down in some form. Later you'll look over these sketches, and become inspired to create others, or to complete the design. I do that all the time.

I like to use the CAD format as it is easier to store, modify, and complete these designs. Since you are still in school, you may want to consider takinng some CAD classes when they are offered.

The exercises Dennis offers are very good. Expand your ideas and horizens, it'll be to your benifit.

Dennis Adamisin · « **Reply #5 on:** July 29, 2009, 11:51:51 AM »

Ditto what John said. Take some CAD classes. When you get to the point of creating a design you will be able to edit easier and add/subtract features you like. Also a handy way to store "stunt numbers" as a starting point to keep you from going too far off the cliff. Any decent CAD class will also be in a 3D solid model format - making it really easy to rotate your new design around and see it from different angles. As John will tell you tho, 2D is still more effective at making model parts drawings.

While you are at it, see it you can get some basic Art classes to improve your skills in sketching and perspective. We are all "wired" to see things differently. For me the sketchpad is a good starter for visualizing things.

Design it in CAD, create laser cutter files and send it off to one of the Laser Cutters to make a "kit"!

Matt Colan · « **Reply #6 on:** July 29, 2009, 12:09:36 PM »

I am going to be in Art II next year in school. I tried to squeeze in technical drawing into my schedule, but couldn't, I'll try again next year. Thanks for the ideas Dennis, I already drew up one in 1/4 scale. This has a modern look, and looks a little like Steve Buso's Kestrel. Dennis, I like both modern and classic looks, and swept back tips the best, like Randy's SV-11 tip. To my eye, the swept back tips make it look like it has air, or smoke coming off the tips, it looks really cool.

Quote from: Dennis Adamisin on July 29, 2009, 10:28:23 AM

What's in a name? All I can say is that it will come to you. I have started some sketches based on a possible name. For example, I took the word "Extreme" and started sketching an extreme stunter. Along the way it became the "No Prisoners" I could show you the sketches - but then I'd have to shoot you...

that's a good idea also, take a word, and design a plane around the word. I already designed a jet styled plane, and one with cheek cowls. Using AutoCad, I'd like to learn how to do it, and getting the parts laser cut for me, and there is a kit of my own

Matt Colan · « **Reply #7 on:** July 29, 2009, 12:27:35 PM »

Dennis, I guess these are the tips you like. These are the ones I favor too!

Edit: I love the looks of this plane also, Windy designs some really good looking ships.

Matt Colan · « **Reply #8 on:** July 29, 2009, 03:33:50 PM »

I spent a few hours coming up with a few 1/4 scale concept drawings. The ones that are shown are the 3 I'm most proud of, the other three, well, I'm not so proud of drawing up. I came up with a V-tail for Denny Adamisin, and a few other stuff.

What'ca think of these

Edit: The last one shown i like the most, with a cowl kind of like Dave Gieke's cowl on the Novi 3, and an anhedral stab. And I stole Windy's canopy that he has on his Novanta.

By the way, each square = 1 inch.

John Miller · « **Reply #9 on:** July 29, 2009, 03:50:46 PM »

That's the idea Matt. I can see the influences that are affecting you. Later, you'll look at these sketches, and be inspired to modify them more.

They look good, I prefer a little more of a slender fuse, but then I don't run a pipe. I do use a rear exhaust engine with a muffler.

Here's a project I'm involved in right now, to illustrate the process a bit.

The first iteration looked lean and mean in the concept stages.

Once I started working on it, I had to apply some aerodynamic rules. The design started to look "portly" to me. Here's where taking those art courses Denny mentioned comes to bear fruit.

It's getting there, and I believe the finished project will have much of the visual impact that the concept drawing does.

The first drawing is the concept drawing, the second is after applying some of the rules, then I realised that I needed more seperation between the wings.

Of course, mine are done on the computer, but what you are doing on paper is every bit as good.

As soon as I can convert my latest on this plane, I'll post where it's gotten to at present. This is not to compare our work, but rather to illustrate some of the design exercises one can go through.

Edit, I've conveted a couple of the drawings to jpegs.

The third one shows the portly, porky looking version when I increased the wing seperation. I felt that the fuselage had to also expand vertically, as the top wing being so much higher didn't look right.

The latest ,or last pic shows me trying to get the "look' back by changing perceptions. This is where that art training can help Matt.

So far, all I've done is changed the size of the spinner. This fools the eye, and makes the fuselage appear to be more in line with the concept sketch.

I'm considering making the fuselage wider so the design has balance, and appears more in proportion to the rest of the design.

These are the advantages of making sketches as you are doing. It gives you a direction, and a visual goal to shoot for.

Keep it up Matt. I think you may have a future in the best non-paying sport out there.

Matt Colan · « **Reply #10 on:** July 29, 2009, 04:08:13 PM »

I could definitely fool around with the planes a little bit, these are just concept sketches, that I definitely think I could improve on. The V-tail, cheek chowled one, I do think is a bit porky looking. These planes all have the same "aerodynamics," nose, tail, wing etc. From memory I tried to reduce the moments of a Patternmaster a little bit so it could come down to around a 56 or 57 inch wingspan

Dennis Adamisin · « **Reply #11 on:** July 30, 2009, 06:24:13 AM »

"Porkiness" is in the eyes of the beholder. If you were to look at the Sharke that Orestes flies you would not a lot of curves and a lot of cross sectional area. It would look "porky" in a side view, but does not come across that way in 3D.

Look to full scale. Cheek cowls are used to cover the cylinders on horizontally opposed engines, The lower chin is usually only a carb air intake. On a Formula 1 racer fuselages are rather small, the X-sections are defined by what is required to keep the pilot covered. some combination of the pilot sitting high relative to the engine (Bill Falck's Rivets) or low relave to the engine (Cassutt) dictate whether the fuselage is more rounded on the top or the bottom. These provide styling cues we can use to generate a pleasing shape.

Oh yeah, try DOUBLING the glass area (height) of your canopy; it will drive you to examine different shapes...

Matt Colan · « **Reply #12 on:** July 30, 2009, 06:43:12 AM »

Ok Dennis, more experimenting today with shapes

Randy Powell · « **Reply #13 on:** July 30, 2009, 12:58:30 PM »

As A guy that does it the old fashion way (you know, drafting board, curves, squares, etc.) I love it. While I can use the basics of a CAD program, it's just not the same, for me anyway, as drawing and looking at what you have full sized. Just a quirk, I guess.

Matt Colan · « **Reply #14 on:** July 30, 2009, 01:39:14 PM »

I also like doing it the old fashioned way, and you can actually see the shape taking place in full size if you are doing a full size drawing.

John Miller · « **Reply #15 on:** July 30, 2009, 02:58:13 PM »

Quote from: Matt Colan on July 30, 2009, 06:43:12 AM

Ok Dennis, more experimenting today with shapes

Matt, I took the liberty to trace your last drawing into my CAD program. I then changed a few items to show how you can easily play with shapes.

This will change the perception, scale, and overall feel of the design.

The total time is about 1/2 an hour.

The top outline is your original, the second has the cockpit doubled in size as Dennis suggested. It really changes the looks doesn't it? The bottom outline I changed the shape of the stab and rudder.

3 concepts, all based on the same design. Easily modified, and stored.

This is one of the reasons for becoming CAD proficient. Also, the files can be used to have a laser cutter make the parts for you.

Matt Colan · « **Reply #16 on:** July 30, 2009, 07:22:08 PM »

Thanks a bunch John!!! I didn't experiment with shapes today, because I had other stuff to do, mow the grass, and flew for the first time since my birthday, the 19th.

I personally don't care for a high canopy like that, if I would make it taller, I would make it half the size of what you made it. I think it is those two things that change the looks of a plane the most, the canopy "shape" and the rudder.

You are right, it changed the whole look of the plane with a couple of very small changes. Now how much do CAD programs cost??? Also, what happened to those tutorials on SSW, I've read through it a little bit, and found it complicated, but then again, I haven't used CAD before.

John Miller · « **Reply #17 on:** July 30, 2009, 09:30:53 PM »

Matt, I would encourage you to continue as you are for a while, but save your sketches. You're taking an art class next year, and try to take some mechanicalo drawing so you learn the basics. If your school offers mechanical drawing, they likely will have a course taching you on CAD, but you'll have to have the hand version of mechanical drawing first.

Once you've done the above, you'll be better able to determine which CAD system will be best for you.

I tried to get some of the basics out on the CAD forum on Stuka, but, it just took tooo much time to continue, and I was trying to teach a generic form that could be used with a little learning curve, in almost any CAD system.

Delta CAD is an inexpensive program, less than $50 that you can download. They have a 30 day free version so you can play with it. It's an easy to use, intuitive program.

Turbo CAD is one of the best, inexpensive, programs available. They used to have a free version of a basic 2D system that you can download.

The problem with self teaching oneself, is, like practising the staunt pattern without a coach, you get so you do your mistakes perfectly. Because of that, I recommend that one take a basic course at least. Cad is often offered in evening classes.

Matt Colan · « **Reply #18 on:** July 31, 2009, 06:51:17 AM »

Next year, I want to take some drafting courses. I think some, if not all have a little thing or a big thing on using CAD. I tried squeezing technical drawing into my schedule for this year, but I wasn't able to

Next year I'm going to try again and I think I'll be able to, since next year, I'm going to have less required classes.

Randy Powell · « **Reply #19 on:** July 31, 2009, 10:41:55 AM »

I think CAD is a tremendous tool. I'd probably use that if I could afford a 36" x 50" plasma screen (and the hardware to drive it) so I could look at a plane full sized. I'd use CAD more (and not doubt get a lot better at it) if I could a bigger display.

One of the advantages for Real World Drafters™ is the tactile sensation.

You have to be able to see what want before you draw it. Being able to picture the plane in your head before you put it on paper is the key. But it would be awfully nice to have stored section images and be about to easily change something like deciding, after the plane is drawn, that you would really like to lower the wing CL an 1/8" or change the rib layout.

James C. Johnson · « **Reply #20 on:** July 31, 2009, 10:48:57 AM »

I for one grew up with a slide rule and drafting table, CAD has been a bit intimidating.. but I am sticking with it.. ... some of my best "designs" are stolen ideas sketched on a napkin in a coffee shop... back when I was head long into RC ... I would draw a design up on a Saturday Night and by the next Sunday I would have it in the air... I was still drawn to using dope or hobbypoxy for my bodies and tails (I caught some flak from the RC guys over that) .. plastic for the wings. Solarfilm from Balsa USA was 4.00 a roll...

Here is a design stolen from the Mod Pod, May 1970 American Aircraft Modeler.. 1986... 60" ws.. 2 channels. .049 on a pod.. a little heavy but a great school yard flier. One evening I was bringing it back with no power and was coming over some huge Maple Trees.. I miscalculated and it went in... I couldn't find it.. 8 months later a friend of mine saw some kids riding down the street on their bikes.. with the plane.. they found it.. my address was in it.. I got it back . I think I gave them $15.. got it home switched out the batt pack and all the gear still worked.. flew it that week again.. it used arrow shafts for wing .. sometimes a design need not reflect changes to the outward structure as much as the inside.

A great draw up ... now steal a wing from Jim Thomerson's Cheap Thrills...

I still love sketching.. you aren't a modeler unless you do...

Jim

Matt Colan · « **Reply #21 on:** July 31, 2009, 02:34:34 PM »

Well I spent today fooling around with one plane, the one I liked the most from my original concept sketches, and fooled around with canopy height and rudder shape, and here is what I came up with:

The first one is the original
The second one I experimented with rudder shape
The third one I changed the canopy and the rudder
The fourth one I went back to the original canopy and the rudder from the third one.

What'ca think?

Edit: the third pic is the second iteration, the fourth one is the third concept, and the second one is the last drawing, if followed on what I said above.

A couple changes and it looks like a completely different design, wow

Bruce Perry · « **Reply #22 on:** September 23, 2009, 10:18:31 PM »

The name is obvious...

M.C.'s HAMMER

or not.... I like the Hammer part, I'd have the "M.C.'s" smaller and high on the left of a significant font with "Hammer"

Yeah there's a reference to an Oooold rapper, but it's your Hammer for the competition.

just a thought.

Nice lines, keep drawing and flying.

B

Matt Colan · « **Reply #23 on:** September 24, 2009, 05:22:38 PM »

Bruce, I'm not into rap, so that doesn't help me, not that I'm building the plane anyways

. Thanks for the comments on my drawings. I did come up with a couple jet styled concept drawings, one that I really like. I've seen on Windy's website pipes that he makes with 2 exhaust holes, well I used that and came up with a jet design with 2 exhaust holes, and a piece of wood dividing the cowl into two areas. maybe I should post them, show you what I've been doing.

Matt Colan · « **Reply #24 on:** September 26, 2009, 09:56:33 AM »

Here are my two latest sketches. Randy Powell, guess which plane is based on your new stunter?

Oh the plane I posted originally, I think I came up with a name for, how about Mercury, the messenger god?

Robert McHam · « **Reply #25 on:** September 26, 2009, 10:24:41 AM »

Mercury sounds good to me. Might use that myself on one!

Robert

L0U CRANE · « **Reply #26 on:** September 29, 2009, 12:37:48 AM »

One day I'll build me a stunter named "Curmudgeon."

What is one of those? Usually a nasty old (flatulence) who not only differs with popular wisdom, but acts out on it...

I'm old enough.

Nasty enough? Have to take the word of others, if I believed anything they said...

But, seriously, folks. I tend to like to look at shapes that could be "real" people carrying airplanes. ...And some shapes that remind people of famous and beautiful prop propelled airplanes. For example, can you say Spitfire?

The fuselage shape is totally up to us - within a pretty wide range, anyway. The big thing about it is this: It is what we see while we are flying the beasts, or beauties, that we build. Some shapes may impress judges with their "prettiness," but does that add or subtract any points from a figure we fly? Anyway, it shouldn't...

The BIG point is that the flier's view must please the flier! Some really different shapes would please me: Hunt's Genesis, with NO vertical tail worth mention (similarly Claus Maikis' Palatin, Chris Lella's (was it) Sundance?). There were others with seemingly oversized vertical surfaces and fuselage shapes (need I say more than Rabe?) All were championship grade, whether despite or because of their fuselage appearance.

The BIG point is that the flier's view must please the flier!

THAT is like any of the so many other things that lend the flier confidence, pride and courage to wring the thing out to the nth. We are, most often, a bit superstitious. If our "best" plug goes south, will we find one to match it? Fuel seems a tad off? Oh, No...! And on and on. When all is right, and feels right, and looks right, we can relax and enjoy letting the good things happen.

But, wait, there's more... The loose nut at the slow end of the flight system has to be tightened just-so to work best. (That's YOU, if you missed my point...) I suspect there must always be some anxiety whether everything will work just right - and that is a good thing. Get sloppy minded and your flying will show it... Get wound up TOO tightly, and your flying will show it. In neither case, it shows good...

Lay out your fuselage side view so that you will have a continuing enjoyment from looking at it practice flight after...etc.^n

don Burke · « **Reply #27 on:** October 24, 2009, 11:06:11 AM »

Matt, keep up the effort.

I have to ditto on the usefulness of CAD. It makes it so easy to change things. Rescaling is one of the best tools. I hardly ever build anything now without a CAD drawing first. Another benefit is that you can correct a lot of mistakes that get expensive when cutting material.

I also have to ditto the suggestion of TurboCAD. If I was starting now it would be my choice. The learning curve is the tedious part. I found that the easiest way to learn the use of a program is to try to make an actual drawing. The tutorials are fine, but until you try to actually do something I find you don't really remember how to.

Matt Colan · « **Reply #28 on:** October 30, 2009, 02:43:33 PM »

The planes the guys use for the Red Bull Air Races, I think would make for some great looking stuntships.

And here are a couple of pics

Matt Colan · « **Reply #29 on:** April 09, 2010, 03:54:13 PM »

In case any of you are wondering if I'm still sketching out possible future stunters, here is my newest one. This is my first attempt at scanning the image, and I was successful!!!

I have noticed in other sketches I have done, that Windy's airplanes are really playing an influence on me, and they all, except this one, contain some of Windy's asthetics in them...

Brett Buck · « **Reply #30 on:** April 09, 2010, 06:27:49 PM »

Quote from: Matt Colan on April 09, 2010, 03:54:13 PM

I have noticed in other sketches I have done, that Windy's airplanes are really playing an influence on me, and they all, except this one, contain some of Windy's asthetics in them...

I would note that the Testarossa and the Novanta are quite a recent departure for Windy as far as the asthetics go. When I think of Windy airplanes, the Cardinal/Strega/Tsunami are the overall basic design approach.

Then there's the Sweeper/MIG...

Brett

Matt Colan · « **Reply #31 on:** April 09, 2010, 07:25:26 PM »

Quote from: Brett Buck on April 09, 2010, 06:27:49 PM

I would note that the Testarossa and the Novanta are quite a recent departure for Windy as far as the asthetics go. When I think of Windy airplanes, the Cardinal/Strega/Tsunami are the overall basic design approach.

Then there's the Sweeper/MIG...

Brett

Hi Brett

I do see what you are saying, I basically meant the last 3 PA planes he's built (Testarossa, Novanta, and Tribute) have had a lot of influence in the way I sketch out stunt ships. His semi-scale planes are still, extremely impressive, the way they are finished and how scale they look.

I heard he built an F-16, anybody got pics of that?

Brett Buck · « **Reply #32 on:** April 09, 2010, 07:49:22 PM »

Quote from: Matt Colan on April 09, 2010, 07:25:26 PM

I do see what you are saying, I basically meant the last 3 PA planes he's built (Testarossa, Novanta, and Tribute) have had a lot of influence in the way I sketch out stunt ships.

The first two are the "new" way and of course the Tribute is a Cardinal ("Tribute" to Big Jim) and the classic styling. You might note a passing resemblance of the Testrarossa and Novanta to this one:

Matt Colan · « **Reply #33 on:** April 10, 2010, 01:18:43 PM »

Quote from: Brett Buck on April 09, 2010, 07:49:22 PM

The first two are the "new" way and of course the Tribute is a Cardinal ("Tribute" to Big Jim) and the classic styling. You might note a passing resemblance of the Testrarossa and Novanta to this one:

Tribute is actually a tribute to his pet bird, Chickie. Maybe it also does have something to do with Big Jim as well.

I sure can tell resemblance to the Trivial Pursuit to the Novanta.

Matt Colan · « **Reply #34 on:** April 10, 2010, 03:07:46 PM »

Here's what I mean by Windy is playing an influence on the way I sketch out airplanes:

In the new sketch, the paper was a little wrinkled when I scanned it, so some of the lines are straight...

Allan Perret · « **Reply #35 on:** April 13, 2010, 07:11:00 AM »

Quote from: John Miller on July 29, 2009, 03:50:46 PM

Here's a project I'm involved in right now, to illustrate the process a bit.

Hey John:
I can see the silloette of a Stalker RE in the Bipe.
What is engine size , span, and area on this project ?

John Miller · « **Reply #36 on:** April 13, 2010, 07:46:11 AM »

Quote from: Allan Perret on April 13, 2010, 07:11:00 AM

Hey John:
I can see the silloette of a Stalker RE in the Bipe.
What is engine size , span, and area on this project ?

Good eyes Allen

I do like the Stalker power, that's for sure.

The "Two Bits" bipe is one of my projects I work on when I don't have a lot of paying drawings to do, so it's taking a little time finishing it up. Here are the dimensions you asked for. Span 51.5", Length 40.375", Area 688 sz. inches, Engine, .60 - .81.

The wings, individually are rather high aspect ratio, combined, in planform, they wind up being rather normal as far as AR goes.

I really need to finish this up, and build it.

Jim Pollock · « **Reply #37 on:** April 13, 2010, 10:16:44 PM »

Matt,

The very first sketch looks very much like a Cavalier, which came to life using aerodynamics by Charles Mackey.
Don't you need to be painting? Do you have your shop set up with humidity controls??

Jim Pollock

Matt Colan · « **Reply #38 on:** April 14, 2010, 10:05:40 AM »

Quote from: Jim Pollock on April 13, 2010, 10:16:44 PM

Matt,

The very first sketch looks very much like a Cavalier, which came to life using aerodynamics by Charles Mackey.
Don't you need to be painting? Do you have your shop set up with humidity controls??

Jim Pollock

The clear is on, it just needs to be assembled, which could be done tonight since I have no homework!!!

Jim Pollock · « **Reply #39 on:** April 16, 2010, 11:31:54 AM »

The big job now is trimming. Read Brett and Ted's trimming articles and the you need to do advanced trimming.
Advanced trimming is nothing more than trying a huge number of props, ensuring that the tip weight doesn't cause
hinging, and there is no hidden sources of yawing. Go get um!

Jim Pollock

Matt Colan · « **Reply #40 on:** April 16, 2010, 04:38:12 PM »

Quote from: Jim Pollock on April 16, 2010, 11:31:54 AM

The big job now is trimming. Read Brett and Ted's trimming articles and the you need to do advanced trimming.
Advanced trimming is nothing more than trying a huge number of props, ensuring that the tip weight doesn't cause
hinging, and there is no hidden sources of yawing. Go get um!

Jim Pollock

Yeah, hopefully this thing will fly off the board. I have gotten some starts on trimming from Dee Rice since he designed the airplane...

Larry Cunningham · « **Reply #41 on:** April 28, 2010, 04:41:38 PM »

Very nice thread. I truly enjoy looking at the noodling going on for CL stunter designs.

As for CAD, it definitely is nice. I personally use AutoCAD, an older version that I inherited from
work just before retirement. However, if you take a CAD class or two at most colleges, you can get
a current "student" version of such programs for a low price. They basically do everything that the
real program does, except the outputs are "crippled" in some manner, say a watermark in the printed
outputs.. And you can find some versions of very strong CAD programs which are fully usable or close
to it, reasonably priced (say ~$150) and are good for a year or maybe longer. Pretty well worthwhile
if you are seriously wanting to learn.

I'm only now trying to learn some 3D stuff, using a borrowed program from a client I consult for. It's
an awesome experience, I figure I'm at about 11% of competency with it. What I'm looking for is the
ability to loft and design shapes like cowls, wing tips, and wheel pants.

In the meantime, I'm just getting around to making some simpler assemblies, but it's very useful for
verifying fits on 2D parts. I can't tell you how longit takes an old dog like me to learn the 3D paradigm.
Below is a sample of a beginning to a verify drawing for my Mo'Beast "modular" laser cut wing assembly.

Also, I suggest you get familiar with splines in 2D CAD as soon as you can. Everything nowadays is
modeled with splines (and ball bearings, as Fletch pointed out to us).

Here's a spline sample, on my fantasy "Stealth Stunter" fuselage "design" (which currently violates 3D
topology..).

Anyway, it's all for fun, and fun is what I seek.

L.

"To observations which ourselves we make, we grow more partial for th' observer's sake." -Alexander Pope

Matt Colan · « **Reply #42 on:** April 28, 2010, 04:57:28 PM »

That plane sort of reminds me of a whale, and this is NOT a bad thing. I actually think it is a cool looking ship.

I have been actually thinking of seriously building a plane of my own design after I finish the Cobra. The plane would be an Oriental Plus with my own style fuse, lengthening the nose about 1/2 inch to allow more room for tank space and maybe not have it as tail heavy if it was. Also I would make the stab/elevator assembly just a bit bigger. The plans say that the stab area is 20% of the wing area, I would make something like 24%. If it has a good corner now, it should grove even better with the bigger stab!!!

steven yampolsky · « **Reply #43 on:** April 28, 2010, 05:38:14 PM »

Quote from: Matt Colan on April 10, 2010, 03:07:46 PM

Here's what I mean by Windy is playing an influence on the way I sketch out airplanes:

In the new sketch, the paper was a little wrinkled when I scanned it, so some of the lines are straight...

Call up Randy Smith and order a bunch of Steve Buso drawings. Talk about gorgeous lines!!!

Matt Colan · « **Reply #44 on:** April 28, 2010, 05:39:54 PM »

Quote from: Steven Yampolsky on April 28, 2010, 05:38:14 PM

Call up Randy Smith and order a bunch of Steve Buso drawings. Talk about gorgeous lines!!!

Yeah, we got a couple of Steve Buso's drawing, the Jaguar and the Lite Wave. The Jaguar is simply GORGEOUS!!!!!!!!!!!!!!!!!

steven yampolsky · « **Reply #45 on:** April 28, 2010, 05:53:41 PM »

Quote from: Matt Colan on April 28, 2010, 05:39:54 PM

Yeah, we got a couple of Steve Buso's drawing, the Jaguar and the Lite Wave. The Jaguar is simply GORGEOUS!!!!!!!!!!!!!!!!!

Have you seen his Freddy Kruger, Friday the 15th design? Bloody awesome.

Matt Colan · « **Reply #46 on:** April 28, 2010, 06:06:00 PM »

Quote from: Steven Yampolsky on April 28, 2010, 05:53:41 PM

Have you seen his Freddy Kruger, Friday the 15th design? Bloody awesome.

No I haven't...

Matt Colan · « **Reply #47 on:** May 01, 2010, 05:49:46 AM »

Here's another new sketch that I don't think looks half bad. The numbers are Oriental Plus numbers with a little longer nose, and larger stab and elevator.

steven yampolsky · « **Reply #48 on:** May 03, 2010, 11:13:31 AM »

Quote from: Matt Colan on May 01, 2010, 05:49:46 AM

Here's another new sketch that I don't think looks half bad. The numbers are Oriental Plus numbers with a little longer nose, and larger stab and elevator.

This looks very cool! The rudder shape looks disconnected . You have this beautiful curve on the wing plan. Perhaps you can incorporate a sweep like that into the rudder. This is just my two cents. What do I know: the cowl shape on my Stoli Special looks like the top of the fuse has a major overbite(dentist talk). I am VERY close to redoing the cowl.

louie klein · « **Reply #49 on:** May 03, 2010, 01:19:58 PM »

Hey Matt, great talent, great future with all the best teachers! I remember that you should always try to make your next plane better than the last, Put improvements in each step and don't try to do it all at once. The box-0-stuff went out Friday and I put notes on the back of the pictures. A couple of vcr tapes with me and mike's hero-Vic "THE JET" Macaluco. Its all fun. Don't let your trailing edge sag, the girls won't like it!-----Louie

Matt Colan · « **Reply #50 on:** May 03, 2010, 03:23:25 PM »

Thanks Louie!!! We're looking foward to your stuff!!!

Edit: Louie, grandpa just told me we got your stuff today! I'm going to head over after I eat dinner, and poke through the stuff you sent us!!!

Quote from: Steven Yampolsky on May 03, 2010, 11:13:31 AM

This looks very cool! The rudder shape looks disconnected . You have this beautiful curve on the wing plan. Perhaps you can incorporate a sweep like that into the rudder. This is just my two cents. What do I know: the cowl shape on my Stoli Special looks like the top of the fuse has a major overbite(dentist talk). I am VERY close to redoing the cowl.

I hadn't really looked at the cowl much, but now I'm going to be looking at that cowl to see what you are complaining about...

Thanks for the comments, I basically copied the rudder shape from Buso's Jaguar, and put the wing tips that I like on it. I've even already come up with a paint scheme for the plane already if I were to build it (minus the wings), I like the shapes of this one that much!!!

maybe I will build it after the Cobra, who knows the future is yet unseen...

Chris McMillin · « **Reply #51 on:** May 03, 2010, 09:54:00 PM »

Quote from: John Miller on July 29, 2009, 03:50:46 PM

That's the idea Matt. I can see the influences that are affecting you. Later, you'll look at these sketches, and be inspired to modify them more.

They look good, I prefer a little more of a slender fuse, but then I don't run a pipe. I do use a rear exhaust engine with a muffler.

Here's a project I'm involved in right now, to illustrate the process a bit.

The first iteration looked lean and mean in the concept stages.

Once I started working on it, I had to apply some aerodynamic rules. The design started to look "portly" to me. Here's where taking those art courses Denny mentioned comes to bear fruit.

It's getting there, and I believe the finished project will have much of the visual impact that the concept drawing does.

The first drawing is the concept drawing, the second is after applying some of the rules, then I realised that I needed more seperation between the wings.

Of course, mine are done on the computer, but what you are doing on paper is every bit as good.

As soon as I can convert my latest on this plane, I'll post where it's gotten to at present. This is not to compare our work, but rather to illustrate some of the design exercises one can go through.

Edit, I've conveted a couple of the drawings to jpegs.

The third one shows the portly, porky looking version when I increased the wing seperation. I felt that the fuselage had to also expand vertically, as the top wing being so much higher didn't look right.

The latest ,or last pic shows me trying to get the "look' back by changing perceptions. This is where that art training can help Matt.

So far, all I've done is changed the size of the spinner. This fools the eye, and makes the fuselage appear to be more in line with the concept sketch.

I'm considering making the fuselage wider so the design has balance, and appears more in proportion to the rest of the design.

These are the advantages of making sketches as you are doing. It gives you a direction, and a visual goal to shoot for.

Keep it up Matt. I think you may have a future in the best non-paying sport out there.

John,
Really cool bipe. i want one. Hey, you know there is a twin engined Stunter named Two Bits, Right?
Chris...

Tom Niebuhr · « **Reply #52 on:** May 04, 2010, 08:00:58 AM »

Hey,

John is into twins and bipes... How about a twin bipe... now that would be different! How's that for a challenge John?

steven yampolsky · « **Reply #53 on:** May 04, 2010, 07:57:32 PM »

Quote from: Matt Colan on May 03, 2010, 03:23:25 PM

I hadn't really looked at the cowl much, but now I'm going to be looking at that cowl to see what you are complaining about...

I am talking about the up curve on the bottom front of the engine cowl on my Stoli Special. The curve on the plans was less aggressive but I thought it would look better. By making the curve up more aggressive than Rick drew, I made two mistakes:
1) While design numbers are Dave Cook's Lighning, the look was penned by Rick Campbell. Rick draws beautiful lines and by not following it, I made a messed up "the look". No one ever told me the model doesn't look good and I try to be objective and be happy with the look but I know the line is wrong and it glares at me every time I fly.
2) This one cost me several contest wins. By making the curve up too aggressive, I ended up with a small intake openning. Not enough air gets through to the engine which causes it to overheat and prevent any kind of consistent engine run during hot days. Another downside is the fact that the small openning gets blanketed by then nose on inside turns and causes the engine to overheat. if I wind them up too hard on inside turns, it takes too long for the motor to settle back to normal temps. Granted, the issue is non-existent if the temps are below 65 but that precludes any kind of summer flying.

Randy Powell · « **Reply #54 on:** May 05, 2010, 09:51:56 AM »

Steven,

>>...I ended up with a small intake openning.<<

I suspect the problem was not too small an opening, but too small an exit. If you have decent flow through the engine compartment you can get away with a very small opening, but you need air exhaust area at least twice as big as the intake. Three times is better. It creates a vacuum in the cowl and draws out the air.

My current plane appears to have a very large intake opening in the cowl. But in truth, the engine is shrouded and the only opening is directly around the lugs and through the cooling fins. However there is a monster opening at the rear of the cowl. Air is sucked through really well. Makes for interesting fluid dynamics.

steven yampolsky · « **Reply #55 on:** May 05, 2010, 01:37:32 PM »

Quote from: Randy Powell on May 05, 2010, 09:51:56 AM

I suspect the problem was not too small an opening, but too small an exit. If you have decent flow through the engine compartment you can get away with a very small opening, but you need air exhaust area at least twice as big as the intake. Three times is better. It creates a vacuum in the cowl and draws out the air.

Any ideas on how to open up a piped engine cowl so that there is enough air flow? Got pictures drawings? Anything!!! I don't want to loose Mass cup to Matt due to engine overheat! I'd rather make him work for it! I have no problem loosing when the other person outflies me but loosing due to things like a poor engine run absolutely infuriates me!

Last fall, I went through a lot of headaches to be able to go to Palisades Park contest. I really wanted to put my skills up against people we don't get in Massachusetts such as Mike Palko and Danny Banjock. I put up a practice flight 5 mintes before the official and when I launched, the engine overheated right away. A was so pissed at myself, I packed everything back in the car and went home. I don't want a repeat of this again!

Steve

Matt Colan · « **Reply #56 on:** May 05, 2010, 07:15:44 PM »

Quote from: Steven Yampolsky on May 05, 2010, 01:37:32 PM

Any ideas on how to open up a piped engine cowl so that there is enough air flow? Got pictures drawings? Anything!!! I don't want to loose Mass cup to Matt due to engine overheat! I'd rather make him work for it! I have no problem loosing when the other person outflies me but loosing due to things like a poor engine run absolutely infuriates me!

Last fall, I went through a lot of headaches to be able to go to Palisades Park contest. I really wanted to put my skills up against people we don't get in Massachusetts such as Mike Palko and Danny Banjock. I put up a practice flight 5 mintes before the official and when I launched, the engine overheated right away. A was so pissed at myself, I packed everything back in the car and went home. I don't want a repeat of this again!

Steve

And I don't want to lose the Mass Cup to you for having the grass being too high, at least I will be able to take the wheelpants off the Oriental Plus.

Randy Powell · « **Reply #57 on:** May 06, 2010, 11:59:02 AM »

Steve,

I think it was Frank Williams that had an article in Stunt News a couple of years ago outlining ways to cool an engine and pipe in a fully enclosed system. Small opening in the cowl for air intake and a huge opening over the pipe exit. The rest of fully enclosed and he had very consistent runs.

I have done this and it works. I've also had systems that had this with the addition of additional air intake directly over the front of the pipe (and the header connector) with another large exit just before the pipe tunnel exit. Really help with cooling.

Shultzie · « **Reply #58 on:** May 06, 2010, 07:10:23 PM »

U bet..."HEATED AIR...ALWAYS EXPANDS and that old speed demon rule...teenie cowling inlets and LARGE EXIT OPENINGS.

Tim Wescott · « **Reply #59 on:** May 29, 2010, 12:53:05 PM »

Weren't you mentioning that you'd gotten your hands on a new motor recently, and wondering what to do with it?

Given that you're churning out these sketches, isn't it obvious?

Get thee to a drafting table, sonny! Flesh those sketches out, and build a model to your design!

(Hint #1 -- I've been a professional design engineer for decades now, and the way to make successful designs is to boldly put in only as much new stuff as is really necessary, and to shamelessly steal the work of others for all the rest. So for inner structure and whatnot, I suggest you find a model that you feel holds up well and is easy to build, and copy it within your external shape)

(Hint #2 -- cover it with all your leftover scraps of plastic film, or by whatever quick method you want. Chances are you'll be cutting into it and changing things; when you're done fiddling with it you can strip it down and re-do it, or build new).

Larry Cunningham · « **Reply #60 on:** May 29, 2010, 01:59:13 PM »

When I was 10, I moved to New Mexico and found a good friend just down the street named Rex Reed. Rex and I had a common interest in model airplanes, 1/2A stuff, and we were inspired by the Scientific models. I remember Rex's Stunt Master, which I admired greatly. I had a Zig Zag which didn't fly as well.

When Rex moved away, we wrote each other regularly, and began including sketches for model airplane fantasies. Rex was a pretty good artist, and we both fed off each other. Over time, we both had explored a lot of interesting model airplane shapes and treatments - noses, cowls, cockpits, gear, rudder, wing and stab were all fair game for experimental renderings. Feeling that requirement each letter to include some new "thinking" led us to some very interesting (and sometimes silly) model airplane shapes.

Eventually Rex and I stopped writing each other, and now I truly wish I had kept some of our sketches.. They fueled a general interest in airplanes and models which neither of us quite got over. Kids nowadays should be so fortunate!

Keep it up, if nothing else you can end up with some pleasant memories.

L.

"You can take a horse to water, but a pencil must be lead." -Stan Laurel

Howard Rush · « **Reply #61 on:** June 10, 2010, 02:58:16 PM »

Quote from: Tim Wescott on May 29, 2010, 12:53:05 PM

Get thee to a drafting table, sonny!

A drafting table? Hey, we're in the 20th Century now.

23 skiddoo.

Tim Wescott · « **Reply #62 on:** June 10, 2010, 03:09:45 PM »

Quote from: Larry Cunningham on April 28, 2010, 04:41:38 PM

Here's a spline sample, on my fantasy "Stealth Stunter" fuselage "design" (which currently violates 3D
topology..).

Looks like the Bugatti race plane (that never flew, unfortunately -- they could have at least taken it for one test hop, just for the benefit of all the scale modelers out there).

I don't see the violation of 3D topology -- or does that not show in the 2-view?

Matt Colan · « **Reply #63 on:** July 19, 2010, 03:17:56 PM »

I've always liked the look of Lambroghini's. I think they just have a mean and aggressive look, and IMHO would make a good looking stuntship if restyled right.

I named it Reventon because it's the name of the Lambroghini I used for inspiration.

How did I do?

Randy Powell · « **Reply #64 on:** July 19, 2010, 04:18:57 PM »

You go, Matt!

My new one will look more like a 59 Chevy Impala low rider.

Howard,

>>A drafting table? Hey, we're in the 20th Century now. <<

Watch it, boy. Some of us still like putting pencil to paper.

Matt Colan · « **Reply #65 on:** July 19, 2010, 06:25:30 PM »

Quote from: Randy Powell on July 19, 2010, 04:18:57 PM

You go, Matt!

My new one will look more like a 59 Chevy Impala low rider.

Howard,

>>A drafting table? Hey, we're in the 20th Century now. <<

Watch it, boy. Some of us still like putting pencil to paper.

Thanks Randy!

a 59 Chevy lowrider sure sounds cool! No chance you could share that or is it relegated to secrecy in your skunk works!

Randy Powell · « **Reply #66 on:** July 20, 2010, 10:40:18 AM »

Matt,

One of the problems with using an actual drafting table is it's tough to share plans

I could shoot a picture of the plan on the wall I guess. When I draw plans, I generally draw them so I can build the plane. An expect builder could probably take the plans and generally know what I was up to, but I look at them and know what I was thinking. A lot of times, I'll start building then figure out that something isn't going to work the way I envisioned it so I will change things on the fly and if I'm paying attention, will do things like trace parts onto the plan on the wall so I can make changes in the plan if I decide to build another one.

I've only actually gone to the trouble of doing a complete, you could build it from this, plan a few times when someone wanted to build a plane I'd done. That's what's making having Walter Umland do a kit of my Ringmaster Deluxe so interesting.

Steve Helmick · « **Reply #67 on:** July 20, 2010, 09:49:31 PM »

I came up with a minor detail idea this week (at work, duh!), that somebody might like. IF you have problems fitting a decent fuel filter into your cowl, anyway. My idea was to essentially run the fuel hose flush with the cowl surface (in a slot) and put as big a filter as desired behind it...even one for an R/C car. Cover it with a scoop that's open on both ends, to camouflage it. Randy would probably stylize it with a widow's peak on the front and bifurcate the exit. Maybe some louvers over the filter? Ghost flames and pin striping to set it off...

Steve

Matt Colan · « **Reply #68 on:** July 21, 2010, 07:24:36 AM »

Quote from: Randy Powell on July 20, 2010, 10:40:18 AM

Matt,

One of the problems with using an actual drafting table is it's tough to share plans

I could shoot a picture of the plan on the wall I guess. When I draw plans, I generally draw them so I can build the plane. An expect builder could probably take the plans and generally know what I was up to, but I look at them and know what I was thinking. A lot of times, I'll start building then figure out that something isn't going to work the way I envisioned it so I will change things on the fly and if I'm paying attention, will do things like trace parts onto the plan on the wall so I can make changes in the plan if I decide to build another one.

I've only actually gone to the trouble of doing a complete, you could build it from this, plan a few times when someone wanted to build a plane I'd done. That's what's making having Walter Umland do a kit of my Ringmaster Deluxe so interesting.

Yeah that is definitely the tough part in terms of sharing. I'm thinking with this plane here, of attempting to make full size plans that I could build off of because I really like the way this thing looks. I am trying to figure out a way in my head to get those panel lines that are on the car. The way I think of it is to glue sticks onto the fuselage sides then just sand them in. I think it would add to the appeal of this plane a little bit. I also got an idea for an air scoop like the Reventon.

All these ideas and i don't even know if I'll even build the plane but it's nice to think about this stuff!

Randy Powell · « **Reply #69 on:** July 22, 2010, 10:44:06 PM »

Matt,

Trust me, I design planes in my head all the time. Weird what may give you an idea.

Matt Colan · « **Reply #70 on:** July 23, 2010, 09:04:13 AM »

Quote from: Randy Powell on July 22, 2010, 10:44:06 PM

Matt,

Trust me, I design planes in my head all the time. Weird what may give you an idea.

Couldn't agree more Randy! And I do see what you're saying about what gives you an idea. I've had this idea for awhile and it looks like it could come to fruition at least on paper, but I still am not sure if I would build it. But you never know!

Larry Cunningham · « **Reply #71 on:** July 30, 2010, 09:03:16 PM »

I'm dating myself here (no one cares) but a long time ago Steve Allen hosted the Tonite Show.
One of Steve's many talents was "on the spot" song composition. He would ask an audience member
to play a few notes on the piano, and then compose a song around it, and give it a humorous name
(for copyright..).

It looked very difficult, yet some of the most unlikely inputs yielded good tunes. Evidently, the
challenge itself turned out to be a fine stimulus.

So what does this have to do with designing model airplanes? I'm suggesting that some novel
and interesting ideas might be spawned from a few nearly random shapes and lines, which become
a "theme" for a finished design.

To guide such efforts, I heartily recommend an article called "Design and Formation" by Claus Maikis,
which I had the privilege to transcribe for PAMPA Stunt News back in 1997 (I think). Claus is a
well known talented industrial artist as well as model airplane designer and flyer - one more Renaissance Man
in our hobby.

Claus' article discussed (with beautiful illustrations) how designs can incorporate themes: important information
for anyone desiring to learn to "design" themes for stunters.

Using a "Steve Allen" approach - taking inspiration from an almost random input might well result in
a fresh creative design. And we pretty well know how to "imprint" our theme or design on a practicable
stunter. We have easy access to the "numbers" associated with successful models. Styling can be less
constrained.

And we might well incorporate the newest "best practice" features to yield an excellent performer. Create
our distinctive styling around the well established technical mode.

Mr. Maikis and a dozen other superb designers and finishers (guys like Al Rabe and Randy Powell..)
show us everything from construction techniques to worthy paint and trim schemes.

With a winning design in hand, all that remains is to learn to FLY like these mentors! I left the hard
part for last.. ;->

A final attraction added to the rich set of technical and artistic experiences is simply "hanging"
with a diverse and interesting group of people. It's what keeps guys like me playing with CL Stunt.

L.

"Everything has been said, and we are more than seven thousand years of human thought too late." -Jean de LaBruyere

Matt Colan · « **Reply #72 on:** March 06, 2011, 08:39:32 AM »

It's been awhile since I've posted a new 1/4 scale sketch of a potential new airplane, so here's one I drew up last night!

This time I took the scientific approach with designing this stunter since I've read some of Ted Fancher's etchings about what to do when designing a new stunter. I also read his Imitation article, which that helped out a lot with understanding why I should have a high drag low aspect ratio stab and elevator etc.

Some numbers for this plane are:

Wingspan: 59"
Wing Area: 660.0625 sq Inches
Aspect Ratio: 5.3:1
Flaps: 16.7% of wing area, and not full span
Nose moment: 9 1/2"
Tail moment: 18 1/4"
Total length: 45" 48 with spinner
tail area: 175.5 sq inches (26.5% of wing area)
Aspect ratio for the tail: 4.2:1

I like it

Tom Niebuhr · « **Reply #73 on:** March 07, 2011, 06:17:03 PM »

Larry,
When I was playing in piano bars, I would ask the pretty girls for their telephone number and make a song out of it. Actually it was easy to do. I had a LOT of fun!

Peter Nevai · « **Reply #74 on:** April 23, 2011, 11:57:42 PM »

Free 3d application, google "Blender 3D". Not a Cad design program, a 3D modeling and rendering application like those used for television and motion pictures.

Tim Wescott · « **Reply #75 on:** April 24, 2011, 10:15:48 AM »

Quote from: Matt Colan on March 06, 2011, 08:39:32 AM

This time I took the scientific approach with designing this stunter since I've read some of Ted Fancher's etchings about what to do when designing a new stunter.

If you ever have to do a year-long science project for school (like, if you go into aeronautical engineering and need it for a senior project), think about building a take-apart plane that'll let you swap wingtips and wings, and maybe even empennage. Then do a series of experiments on how each change affects the handling of the plane.

If you go to someplace that does senior projects in teams (like WPI in Massachusetts), then maybe you'd have enough members on the team to do wind tunnel testing, to put numbers to the changes in "feel". I think CFD is still fantasy for model-scale efforts like this, but maybe not -- computers just keep getting faster, after all.

Howard Rush · « **Reply #76 on:** April 25, 2011, 07:22:54 PM »

Quote from: Matt Colan on March 06, 2011, 08:39:32 AM

I also read his Imitation article, which that helped out a lot with understanding why I should have a high drag low aspect ratio stab and elevator etc.

Why should you?

Howard Rush · « **Reply #77 on:** April 25, 2011, 07:26:55 PM »

Quote from: Shultzie on May 06, 2010, 07:10:23 PM

U bet..."HEATED AIR...ALWAYS EXPANDS and that old speed demon rule...teenie cowling inlets and LARGE EXIT OPENINGS.

Not because the air expands. Remember PV=nRT? What were you doing during that class?

edited for assholicity

Matt Colan · « **Reply #78 on:** April 26, 2011, 03:37:17 PM »

Quote from: Howard Rush on April 25, 2011, 07:22:54 PM

Why should you?

It creates less load on the control system to get the plane to turn, and also makes it easier on yourself. Furthermore, it allows you to have a more aft CG than a conventional classic ship with the smaller tail sections.

Howard Rush · « **Reply #79 on:** April 26, 2011, 07:40:33 PM »

I didn't notice the "etc.", which I guess says to have a big tail. A big tail allows the CG to go back, which reduces hinge moment (control load). I thought you were referring to reduced hinge moment, the capablility to move the CG back, and drag as virtues of a low-aspect-ratio tail, which they are not: elevator hinge moment is approximately proportional to elevator area x chord. Tail effectiveness is a function of size and shape. (I can send you a spreadsheet that gives a better answer than tail volume, but is still easy to find the numbers for.) Textbooks say, for good reason, that you can ignore stab drag for stability purposes. I have been pestering people to explain why they use low-aspect-ratio tails, because I am planning not to do so on my new dog. I haven't read Ted's article, so I was curious as to what it said.

Using the aforementioned spreadsheet, I figure that the tail on my current airplane is 82% as effective as a standard Impact's. The one I intended to put on my new dog would have been about 113% as effective as a standard Impact's tail. However, I sanded the tips backward: roundy at the TE and tapered toward the LE. This wouldn't have fit the elevators, so I recarved the tips, reducing the aspect ratio and reducing the tail effectiveness to 106% of that of a standard Impact.

Best I can figure, a low tail aspect ratio gives a stiffer tail, which is good. Also, a large stab chord makes the Reynolds number higher, which could keep the laminar-turbulent transition point from misbehaving, if I correctly understand Igor.

Randy Powell · « **Reply #80 on:** April 27, 2011, 11:23:58 AM »

And in the end, you'll have an Impact.

Howard Rush · « **Reply #81 on:** April 27, 2011, 03:18:30 PM »

That would be good, but as you know, it's hard not to stray off the path.

PJ Rowland · « **Reply #82 on:** April 27, 2011, 11:46:42 PM »

Howard and I figured out how to reduce control loads 10 years ago.....

Randy Powell · « **Reply #83 on:** April 29, 2011, 10:23:23 AM »

Curls?

PJ Rowland · « **Reply #84 on:** April 29, 2011, 07:57:06 PM »

Well I cant speak for howard but curls are part of my stunt fitness regime - Rush-boost tabs

Brian Hampton · « **Reply #85 on:** April 29, 2011, 08:27:28 PM »

Back in about the mid '70's I built this huge 6 foot span stunter powered by a Taipan 61 that I used to fly at Moorabin airport with Peter White and the rest of the mob. It was a handfull so I fitted boost tabs to the elevators in an attempt to ease the loads. I got the idea from a large RC aircraft I used to work on at Woomera...the Jindivik

.

PJ Rowland · « **Reply #86 on:** April 29, 2011, 09:54:51 PM »

I have tried multiple configurations over the past 15 years - I found no signifgant improvement in reduction of stick force running them from the elevator. There simply is too much load from the flaps.

The reasons it works for rc to reduce servo load is that the elevator is running independant from the rest of the system. Our planes are coupled flaps to elev, so the effectinvess must be taken into consideration as a full package force load reduction system.

I flew the lancaster with Boost tabs fitted ,it was as easy to fly as any classic ship inregards to stick force - pull load was another story, I estimated during manouvers pull loads went close to 30 pound. We estimated this rather crudely, just after a flight I had someone hold a pull test machine and i had them pull whilst I was blindefolded and when I felt the load was that of what I experienced in flight it read 26.7 pounds. Im convinced in wind It moved a little higher.

We are taking 121 oz 2 m - 4 engined monalith. Boost tabs were extremeley effective in stick force reduction.

Conversely its proportinate to model size - I have run them on something as small as a 1951 Nobler, and noticed no improvement or reduction over standard. yet on my .81 sized 620sq 62 oz sq ship they work perfectly.

Nice to hear your experiences also. Elevator force reduction effectiveness? Not in my experience.

Author Topic: What I like to do when I'm bored (a new sketch) (Read 18733 times)

steven yampolsky

steven yampolsky

steven yampolsky

steven yampolsky

steven yampolsky