Chapter 13
DESIGN
Simplicate and add lightness.
- Attributed to many sources.
Don't ask who, just do it.
According to Webster's definitions, to design is "To devise or
propose for a specific function." And, "To conceive and plan out in
the mind." That seems to be an accurate description of what model
building is all about.
13.1 Design To Do What?
The first things one must take into consideration when creating a
design for a model aircraft are how it will be used and what
requirements and limitations will be placed upon it. In Chapter 2 we
saw the great diversity that exists in Model Aviation. There is no
generic, one-size-fits-all design, and there is no one-design
reference book that can deal with all aspects of the hobby.
In competition, we must design within the limitations of event rules.
If the rules are too restrictive they limit creativity.
In controlled flight (radio control and control line) the modeler can
stray from "good aerodynamic design", just as the Stealth Fighter
example did in Chapter 12. I have a friend that flies a
radio-controlled model shaped like a witch on a broom, and another
styrofoam R/C that looks like a stop sign. One of his unique indoor
models sports an inscription on the wing, "It does so fly." (and it
does) A beginner's U/C model featured at Web site www.aeromaniacs.com is a simple disc.
The point is that controlled flight permits some design flexibility. An uncontrolled (free flight) model depends, to a degree, on stability to quickly recover from wind gusts or transition from powered to gliding flight.
13.2 Measuring the Result
Experienced designers carefully record the performance of their project and
the results obtained when changes are made. It's a good idea to maintain a
small notebook for each model. Record basic criteria such as thrust angles,
center of gravity, decalage, trim settings, number of rubber strands, weather
conditions, flight times and any other variables. Next time you fly, the
model can be set up correctly using that data, saving time. Of more
importance, you have recorded a standard of performance. When design changes
are made you can compare performance results to that standard. See Appendix B Charts and Coordinates for some applications in which plotting numerical
information can define performance or establish shapes. Also see Appendix E - Building Light and Strong regarding the benefits of weight reduction to improve performance.
13.3 Model Design Reference Sources
You may find some minor differences of opinion in the following
respected source material. Modelers enjoy healthy debate about such
things in their model clubs, Internet forums and mailing lists. To
get the most inspiration, education and just plain fun from the
hobby, study both sides and choose what works best for you.
13.3.1 Books
- [Gitlow, Lew. Indoor Flying Models. Self published at Box 5311,
Salem, Oregon 97304.] Introduces the requirements of design for a
range of Indoor Rubber Model Events.
- [Lennon, Andy. Basics of Model Aircraft Design. Ridgefield, CT:
AirAGE, 1996.] A comprehensive guide to designing radio control
models.
- [Malkin, John. Airfoil Sections. Self-published] Provides
information about how to plot airfoils. The book consists mainly of
airfoils of interest to model builders. Available through book
dealers such as Hannans Runway.
- [McCombs, William F. Making Scale Model Airplanes Fly for Sport or
Contests. Self published at: 2106 Siesta, Dallas, Texas 75224] A book dealing with a range of power sources. While Chapter 5 specifically covers design and model selection, the entire book provides practical insight into the details of model design.
- [Ross, Don. Rubber Powered Model Airplanes. Hummelstown, PA:
Aviation Publishers, 1998.] A book of how-to basics for the
beginning modeler. Chapter 17 is devoted to designing your own
rubber model.
- [Ross, Don. Flying Models-Rubber, CO2, Electric and Micro Radio
Control. Hummelstown, PA: Aviation Publishers, 1998.] Chapter 2
deals with weight distribution; Chapter 4 outlines a unique design
approach that features the evolution of a model through a range of
power sources.
- [Simons, Martin. Model Aircraft Aerodynamics. 4th ed., Swanley,
Kent, Great Britain: Nexus Special Interests, 1999.] A book about
Aerodynamics as it relates to the design of Model Aircraft. First
printed in 1978, this fourth edition is evidence of the long-standing
popularity of this book.
- [Williams, Ron. Building and Flying Indoor Model Airplanes. Salt
Lake City: Peregrine, 1984.] This book is out-of-print but much
sought after because of its detailed coverage of indoor rubber
models. Most design comments are found in chapter one.
13.3.2 Web Sites
13.3.3 Related Web Sites
-
yourdictionary.com A Web site listing of dictionaries
-
world.altavista.com/ and click babelfish a translation Web site that allows you to enter words and receive translation in nine different languages.
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