Build A Telescope
Written by Tammy Plotner
Have you ever wanted to build a telescope? How much does it cost and where do you get the parts? What types of telescopes can a amateur build easily? Are there kits available to build a telescope? Are there instructions for a science class or project? Putting together your own telescope is a fun and rewarding project that teaches you a lot about the physics behind the optics – no matter if your telescope making project is from simple, household materials or an exotic kit. In the case of amateur telescope making, there's thousands of resources to choose from, but if you have a few questions like above, then follow along as we explore how to build a telescope.
Build A Telescope From Simple Materials
Have you ever wanted to just build a telescope to see how it works? With just a few simple materials, you can do it very easily! All you need is 2 converging (convex) lenses such as you might find in different sized small toy magnifying glasses, telescoping tubes (mailing tubes, or cardboard tubes which can slide inside each other), a manila file folder, scissors, serrated knife or saw to cut the tubes, glue, and some poster board. It's as easy as 1, 2, 3. Are you ready?
1. The mailing tubes will be the body of the telescope with the smaller one sliding inside the larger one. The length of the assembled telescope will be a little longer than the sum of the focal lengths of the two lenses. To determine the focal length, have someone hold a flashlight above the lens and move it up and down until the light shining through the lens comes to a bright point and measure the distance. Add the value of the focal lengths of the short and long lens together. Divide that length by two and then add another inch. Cut both of the tubes to that length with a knife or saw.
2. Use the scissors to cut out two circles from the manila paper that are the same size as the diameter of the mailing tube. These circle frames will mount and center the lenses on the tube. With a knife, cut out circles that are slightly smaller than the diameter of the lenses in the center of the paper frame circle. Glue the lenses to the center of the frame. The shorter focal length lens will be the eyepiece. Glue that framed lens to the end of the smaller tube. Glue the other framed lens to the end of the larger tube.
3. Slide the two cardboard tubes together. You have now assembled a simple refracting telescope. Look through the eyepiece of your telescope and focus it on a distant object. Slide the two cardboard tubes in and out until you have a clear image.
Now you have made your very first refractor telescope! While this isn't a good as what can be achieved with better lenses and materials, you're well on your way to learning what it takes to build your own telescope. Take a look around on the web. Many science based companies offer kits to build your own refractor that are equal to what Galileo first used! These kits are also available in multiples for classroom work.
Build A Telescope From Plans or a Kit
A simple refractor telescope is easy to construct from paper and lenses, but a reflector takes a lot more work. There are many books
, videos and websites devoted to nothing but the art of building your own telescope! Building a telescope isn't difficult, but it is much easier if you have a good set of instructions and a list of parts which you will need like the tube, mirror cell, diagonal mirror, the spider vane and diagonal mirror mount. You can either chose to grind your own mirror from a mirror blank or buy the mirror ready made. The choices are infinite.
If you decide to build a telescope from plans, where do you get the plans and the parts? As you may have already discovered, the internet is one of the most reliable sources for finding what you need and most companies which supply ready made telescopes also supply the necessary parts to create your own telescope as well. Once you have your plans in hand, it is usually a matter of choosing your cabinet style and woodworking. Afterwards, you begin the optical tube assembly. Perhaps you may even choose to use an old telescope and give it a new look! Building your own telescope from plans and purchased parts can be relatively inexpensive – from a couple of hundred dollars up to what you want to invest. There are even simple telescope plans make from plastic plumbing parts available, too.
Are you interested in building a reflector telescope from a kit? Those are also available, too. These kits can be as simple as the cardboard tube style which we have just explored, to elaborate models which replicate antique historical telescopes. Just as with amateur telescope making – referred to as ATM – there are myriad resources to choose from. One of the best and most reliable internet sites to start you quest from is Amateur Telescope Maker. Here you will find most of the resources you need to begin to build your own telescope!
Build A Telescope For Classrooms of Groups
Image by: Patrick Wilken
To make a more precise pinhole, trying layering the foil when puncturing it. Then choose the one layer with the best, round hole. Small holes usually produce the best image, but experiment with them all and note your results with each size and shape. Begin by holding your pinhole eyepiece against your eye and look at a brightly lit scene. Now, put the magnifying lens against it and move slowly outward. You'll know when it's working! Try different distances and see where the image appears rightside up – or upside down. It's hard to believe a telescope could be made so simply, but it's true. The pinhole projector, minus the lens, has been in use for centuries and was the basis for one of the very first solar telescopes. However, remember your simple science principles and what happens when you focus the sun's rays through a magnifying glass. Your retina will burn far more quickly than any piece of paper! Never focus any kind of optical aid towards the Sun without a proper solar safety filter.
So, you see, building a simple telescope can range from a few cents worth of materials to hundreds of dollars. The main point is to enjoy your experiments and you'll learn much more about the physics of optics and how telescopes work!
Filed under: Astronomy
