Building a Telescope?

Roberto Garza

It is not as hard as some people think. Anybody can do it! It only requires a few simple elements: interest in astronomy, some house tools and above all, patience. If you have a basement or garage along with a hand saw, hack saw, drill, measuring tape, and screwdriver, you have it made!

A telescope can be made of any material imaginable: metal, wood, cardboard ("Sonotube"), fiberglass, wire mesh with some kind of inside skeleton, PVC pipe, and I've even seen one made of woven reed (rattan). It can be square in shape, cylindrical, or with enclosed ends connected by aluminum pipes called trusses. It can even be with a tripod shape if you are willing to build a YOLO system. The shape of the instrument does not matter as long as the specs are met, which means the distance between the optical elements is correct for the focal length of the lens or mirror. The secondary in a reflector system needs to be positioned correctly at a 45o angle; with a refractor, the distance from the objective lens to the star diagonal must be correct.

The cheapest to build is the Newtonian type with a Dobsonian mounting. It takes anywhere from 20 to 60 hours if you buy the optics, and 50 to 100 hours more if you choose to grind your own mirror.

Wood is the most common material due to its good thermal qualities. Besides being cheap, it is available anywhere, even at the large hardware chains that also carry some of the other materials needed. The best place to buy wood is Builder's Square; they even cut the wood for you to an accuracy of about 1/16 inch. If you are good with a measuring tape, this is the way to go.

Before you acquire any of these materials, it is imperative that you buy an instruction book. There is a good one written by Richard Berry (Build Your Own Telescope), which covers the construction of several telescopes up to 10-inches in size. He explains everything in an easy step-by-step way which anybody can understand, even if he or she never built a telescope before. This book can be purchased from Sky Publishing (800-253-0245). It's also available from Telescope and Binocular Center (800-447-1001), better known as "Orion Telescopes", which besides selling all kinds of components also carries good quality optics. If your budget is limited, The Starry Messenger is a publication that advertises a lot of brand name and homemade used optics (201-992-6865).

It really helps to attend star parties, especially ASTROFEST, which is famous for its 300+ telescopes on display. At least half of them are usually homemade. Browsing around the grounds will give you a good idea of the materials and technology used by many telescope builders. Of course, you can avoid the gruesome details of building your own by buying a brand new telescope, or even a used one. But nothing beats touring the universe through an instrument you built with your own hands.

Published in the August 1997 issue of the NightTimes