Chapter 13

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 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

  • A Web site listing of dictionaries

  • and click babelfish a translation Web site that allows you to enter words and receive translation in nine different languages.

Return to Chapter 12

Proceed to Chapter 14

Copyright 2002, Robert S. Munson. All Rights Reserved