steveo64

My Feedback: (6)

I am looking for a design reference. I have several wings and I would like ot design some small planes around them.

The problem is, I don't know the correct wing, motot or tail incidence for 3 channel or 4 channel planes. Also, for a three channel, what dihedral will give me best results?

I am looking for a practical chart of these things or a book I can get that would have them in it.

Any suggestions?



[email protected]

majortom-RCU

My Feedback: (40)

Two good places to start are the article by Howard Sullivan on Practical Model Design at <uoguelph.ca> and Ed Moorman's Articles on Design & Construction, especially RC Design by Prop, at <members.home.net/moorman1/articles>. There are a couple of worthwhile books on model airplane design, and the best way to get at them is to search that subject on amazon.com. The classics tend to devote a lot of deep discussion to theory that the shorter articles cut through to the heart of very quickly. The question of dihedral has no simple answer, since dihedral tuning for desired performance has to balance with a number of other design considerations (high wing, mid-wing, low wing, sweepback, sweepforward, self-righting vs aerobatic performance, etc.). If you just imitate the wing airfoil/planform/position on fuselage/dihedral designs of popular models that fly the way you want yours to fly, that's as good a simple guide as any. Aerodynamic theory is all very interesting, but the best model designs get that way by someone starting with an approximation, then iterations of test flying, redesign, rebuilding and more testing and tuning.

Once you've built a model, its potential will emerge only when it has been properly trimmed, which is a whole 'nother subject. A good start in this area is at the same uoguelph site referenced above, Howard Sullivan's Trimming Tips; NSRCA.org "Technical" menu button; and aerobatix.com articles.

If you don't have the "For What It's Worth" series from RCModeler (seven books in the series), there are many design articles scattered throughout the series that are great reading, and the total of useful information (and occasional misinformation) is worth the modest cost.

My final thought is the best way to learn is by building something and trying to get it to fly. Almost anything with wings, tail and motor can be gotten up into the air, and that's when the fun begins. Crash and rebuild is an honorable and effective education.

For my money, this is the best part of RC flying.

Cactus.

My Feedback: (1)

I dont normally design my planes with any natural stability, thats why i have control of it. so i draw a imaginary line between the trailing egde and front of the eading edge, and have this lined up with the tailplane for 0 degrees incidence. if you want some stability ZZZZZZZz yawn, then aim the leading edge up a degree or two, but its a myth the plane will recover its self if you let off the sticks, never seen it happen. if you want diheral ZZZZZ lol then a inch under each wingtip normaly does the trick., if you want 3 channel. forget rudder, nasty slow planes, fun fighters are always more fun, and no doubt one of those wings could give you a mustang or ME-109. best way... if it looks right, it'll fly right, theorys are fine, but anything can fly, better to have your first own build that flys ok, than spending months in books on something that flys better when you probably wouldnt notice too much. go have fun, its what this hobby is all about.
the kid in this pic always comes to the field with new weird and wonderfull planes, some fly some dont, but we always have a laugh

AlphaWhisky

I suggest you invest in a copy of 'Designing Model Aircraft' by Peter Miller.

This is a simple, no nonsense publication that will provide you with straight forward information to enable to to get your creation aloft in shortorder.

I seem to recall it is available ex MAN.

Alan W

Jester

If I had to pick one book, it would be "Basics Of R/C Model Aircraft Design" by Andy Lennon, published by Air Age (MAN), ISBN: 0-911295-40-2. It covers all the basics: airfoils, wing loading, CG location, basic proportions, aerobatic design, landing gear design, prop selection, canards, tailless aircraft, hull and float design, and more. Basic theory is included but the book doesn't get bogged down in it.

steveo64

My Feedback: (6)

Thanks everyone!....I have some reading to do.

Steve

majortom-RCU

My Feedback: (40)

Steveo, after you have done your reading, you might consider a simulator program (if you don't have one). I've been using Realflight Gen 1 & 2. This stuff is not cheap, especially if you have to upgrade your computer equipment to get good 3D video, but it can't be beat for what it saves in time traveling to the field, setting up, buying fuel and all that. In the Edit Aircraft menu you can vary just about any design feature including dihedral angle, incidences, control throws, thrust offsets, change engines, change props, move cg back and forth, etc. to your heart's content, then fly the model with a very realistic simulation of the effect your changes have. To get the most out of the experience, you need to fly a sequentially ordered trim procedure such as on the NSRCA or Sullivan websites. If you get the various add-on cd's, you can find a model that approximates almost anything you might have in mind for a scratch design, and learn enough to save you countless hours, and probably months of building and testing. Here in snow country, a simulator and a building project keep me busy and learning when flying is not an option.

FCC

phillybaby

How fat you are....
Sorry just kidding, but nice photos....

Cactus.

My Feedback: (1)

I think you'll find i said...

the kid in this pic always comes to the field with new weird and wonderfull planes, some fly some dont, but we always have a laugh

thats cartman, and if you go to my thread in the hanger hangout, weird planes, you can see another of his.

im a skinny streak of pi$$ me lol
and ALL! of my planes fly, ok, the Drag Queen didnt if you threw like a girl lol