Portable Newtonian Telescopes [By Highe]

Title: Engineering, Design and Construction of Portable Newtonian Telescopes
Author(s): Albert Highe
Other Info: 6" by 9", 694 pages, Hardbound, 2.75 lb item wt.

Engineering, Design and Construction of Portable Newtonian Telescopes is a massive 694 page book with 472 illustrations and 113 tables that tells you how to design and build a portable Newtonian telescope that performs better, weighs less, and increases your enjoyment of its use. Simultaneously accomplishing all three of these goals requires specific knowledge and abilities many telescope builders initially do not have. Not to worry. This book helps you acquire them. The author distills his years of experience into concise descriptions of engineering principles and material properties relevant to amateur telescope making. You’ll understand how structural elements behave, and be able to evaluate and select appropriate construction materials. Reducing weight and size can make any telescope easier to move, reassemble, and store. But many steps to reduce weight also can reduce structure stiffness, increasing vibration amplitude and duration. The author explains where to look for, and how to compare, weight-reduction opportunities, and how to select and implement those with little or no impact on stiffness. The book describes the design and construction of two specific telescopes. They demonstrate that even with moderately-large instruments, you can eliminate the stepstool or ladder and be seated comfortably at the eyepiece. Their lengthy chapters, profuse with images and drawings, and extensive construction detail, will lead you through the steps required to build an attractive, functioning telescope that meets exacting goals.

In many cases, engineering equations provide sufficient insight and direction to ensure the completed telescope will meet your expectations. However, real-world structures don’t always achieve anticipated performance. The author emphasizes the importance of making decisions based on data rather than on theory or accepted lore. For example, his extensive testing of three- and four-truss structures revealed some unappreciated/unknown aspects of common practices. One of the book’s major contributions is the subsequent creation of quantitative design rules for the construction of effective telescope trusses. The design rules are easy to use, having been incorporated into Excel worksheets that allow you to explore the consequences of varying strut materials, strut and truss dimensions, and connection methods. Similarly, other worksheets allow you to quickly lay out optical components and evaluate their impact on field illumination, telescope balance, and eyepiece height, and calculate deflection of beams and other structures as a function of size, shape, and load.

When buying a commercial telescope, or copying an existing design, one accepts the compromises made by the builder. When making your own, you can have features that no manufacturer could provide and remain profitable. The goals of anyone thinking of building a telescope should include optimized performance, weight, and comfort. There is no better introduction how to achieve them than this book.