How To Do A Telescope

If you’ve ever looked at the stars and wondered how to do a telescope yourself, you’re in the right place. Building your own telescope is a rewarding project that brings the universe closer without needing a huge budget. It’s easier than you might think, especially if you start with a simple design.

This guide will walk you through the process step-by-step. We’ll focus on a basic Newtonian reflector telescope, which is perfect for beginners. You’ll learn what parts you need, where to get them, and how to put it all together.

This section is your complete roadmap. We’ll break down the entire build into managable stages. First, you’ll gather your materials and tools. Then, you’ll assemble the optical tube, mount, and finally align everything for your first night of viewing.

Understanding Telescope Basics

Before you start building, it helps to know how a telescope works. A simple reflector telescope uses two main mirrors. The primary mirror collects light from a distant object. It reflects that light to a smaller secondary mirror.

The secondary mirror then directs the light into the eyepiece, which is where you look. This design gives you a lot of light-gathering power for a relativly low cost. That’s why it’s the best choice for a first-time builder.

Key Components You’ll Be Making or Sourcing

Primary Mirror: The heart of your telescope. You can buy a pre-made mirror or grind one yourself (a more advanced project).
Secondary Mirror: A small, flat elliptical mirror that directs light out the side of the tube.
Optical Tube: The main body that holds the mirrors and blocks stray light. Often made from sonotube (concrete form tube) or PVC.
Eyepiece: The lens you look through. You’ll buy this separately; having a couple with different magnifications is best.
Mount: The stand that holds your tube steady. A simple Dobsonian mount is easy to build and very stable.
Focuser: The mechanism that holds the eyepiece and allows you to slide it in and out to achieve a sharp focus.

Gathering Your Materials and Tools

You can source most of these items from a hardware store, online retailers, or specialty telescope supply shops. Don’t feel pressured to get the most expensive options. A functional scope is the primary goal.

Materials List

Pre-made parabolic primary mirror (e.g., 6-inch diameter, f/8 focal ratio is great for starters)
Elliptical secondary mirror (size matched to your primary)
Sonotube or large-diameter PVC pipe for the tube (length should match your mirror’s focal length)
Plywood sheets (½-inch and ¾-inch thick) for the mount and mirror cell
Focuser (1.25-inch rack-and-pinion is standard)
Spider (the vanes that hold the secondary mirror centered in the tube)
Epoxy glue, screws, and bolts
Flat black spray paint (for the inside of the tube)
Finder scope (a small, low-power telescope attached to the main tube to help you aim)

Essential Tools

Jigsaw or circular saw
Drill with various bits
Screwdrivers
Measuring tape and ruler
Compass (for drawing circles)
Sandpaper
Paintbrush

Step-by-Step Assembly Guide

Now for the hands-on part. Work in a clean, well-lit space and take your time. Precision here makes a big difference in final performance.

Step 1: Building the Optical Tube

Cut your sonotube or PVC to the correct length. This is usually slightly shorter than the focal length of your primary mirror.
Paint the entire inside of the tube with flat black paint. Let it dry completely. This prevents light reflections.
Determine the exact spot to drill the hole for the focuser. Measure from the front of the tube (the end opposite where the primary mirror will sit) a distance equal to the radius of the tube. This is where the eyepiece will go.
Carefully cut a round hole for the focuser to mount. Attach the focuser securely using the provided screws.

Step 2: Installing the Mirrors

Construct a mirror cell from plywood to hold the primary mirror. It should support the mirror around its edges and allow for adjustment screws. The mirror should face the open end of the tube.
Secure the primary mirror in its cell at the bottom end of the optical tube. It must be centered.
Attach the spider to the inside of the tube, directly in line with the focuser’s hole. The secondary mirror will mount to the center of the spider.
Glue the secondary mirror to its holder. Then, attach the holder to the spider. The mirror should be angled at 45 degrees to direct light into the focuser.

Step 3: Constructing the Dobsonian Mount

A Dobsonian mount is a simple box that rotates side-to-side, with the tube tilting up and down. It’s made from plywood and uses smooth bearings for movement.

Cut the plywood pieces: a base, two side bearings (rockers), and a cradle that holds the tube.
Assemble the rocker box. It should be sturdy and square.
Attach Teflon pads or similar slippery plastic to the bearing surfaces. This allows for silky smooth movement when you push the telescope.
Secure the tube into the cradle using straps or clips. The balance point should be near the pivot points.

Aligning Your Optics (Collimation)

This is the most critical step after assembly. Collimation means aligning the primary and secondary mirrors perfectly. If they are out of alignment, your images will be blurry.

Point the tube at a bright wall or the daytime sky (NEVER at the sun).
Look through the focuser (without an eyepiece). You should see the reflection of the primary mirror, the secondary mirror, and the three clips holding the primary.
Adjust the screws on the spider until the secondary mirror is centered in your view.
Then, adjust the screws on the back of the primary mirror cell until the reflection of the secondary is centered in the primary. All the reflections should look concentric.

First Light and Testing

“First light” is what astronomers call the first time you use a new telescope. Choose a bright, easy target like the Moon.

Start with your lowest-power eyepiece (the one with the highest mm number, like 25mm).
Slide it into the focuser.
Point your telescope using the finder scope. Adjust the finder scope in daylight so it’s aligned with the main tube.
Look through the eyepiece and slowly turn the focuser knob until the image becomes sharp and clear.

If the image is crisp, congratulations! You’ve successfully built a telescope. If it’s blurry, re-check your collimation. Atmospheric conditions can also affect viewing.

Tips for Better Viewing

Let your telescope adjust to the outside temperature for at least 30 minutes before serious observing.
Observe from a dark location, away from streetlights.
Keep a logbook of what you see and your observations.
Be patient. Seeing fine detail on planets or faint galaxies takes practice.
Join a local astronomy club. They can offer invaluable advice and inspiration.

Common Troubleshooting Issues

Every new builder encounters a few hiccups. Here’s how to solve common problems.

Image is Always Blurry

This is almost always a collimation issue. Revisit the collimation steps carefully. Ensure all screws are tight after adjustment. Also, check that your eyepiece is clean.

Telescope is Wobbly

Check all the joints on your mount. Tighten any loose bolts. Ensure the bearing surfaces (Teflon on Formica) are clean and smooth. The tube should move with just a light touch.

Can’t Find Anything Through the Eyepiece

First, align your finder scope in daylight on a distant object like a telephone pole. Point the main tube at it, center it in the eyepiece, then adjust the finder’s screws until it’s pointing at the same spot. This makes night aiming much easier.

Taking Your Project Further

Once your basic telescope is working, you might want to improve it. You can build a better focuser, add setting circles to find objects by coordinates, or even build a larger mirror for your next project. The skills you’ve learned here apply to all of those.

You can also make accessories. A simple lens cap, a dew shield made from craft foam, or a more comfortable observing chair will enhance your experience. The community of amateur telescope makers is full of great ideas you can borrow.

FAQ Section

How hard is it to do a telescope at home?

It’s a moderate DIY project. If you can follow instructions and use basic tools, you can absolutely do it. Starting with a pre-made mirror simplifies the process significantly. The mount construction is basic woodworking.

What is the cheapest way to do a telescope?

The cheapest method is to find used or surplus optics and build the tube and mount from scavenged materials. PVC pipe and plywood are very inexpensive. The main cost is usually the primary mirror and the focuser.

How long does it take to do a telescope from start to finish?

For a first-time builder, plan for a weekend project. One day for gathering materials and cutting parts, and a second day for assembly, painting, and collimation. Don’t rush the collimation step; it’s worth taking extra time to get it right.

Can I use glasses lenses to do a telescope?

No, you cannot use standard eyeglass lenses. Telescope mirrors and eyepieces require precise optical curves (parabolic for the main mirror) that are not found in reading glasses. Using the wrong optics will result in very poor images.

Is it cheaper to do a telescope or buy one?

For a small telescope, buying a mass-produced one is often cheaper. However, building one lets you create a larger aperture scope for less money than a commercial equivalent. The real value is in the knowledge, pride, and customization you gain.

What can I see with a homemade 6-inch telescope?

You can see a tremendous amount! The Moon’s craters in great detail, the rings of Saturn, the cloud bands on Jupiter and its moons, bright nebulae like the Orion Nebula, and many star clusters. From a dark site, you can even see some galaxies.

Building your own telescope opens up a new perspective on the night sky. The satisfaction of seeing Saturn’s rings through an instrument you built with your own hands is unforgettable. It connects you to centuries of astronomers who crafted their own tools. With this guide, you have a clear path from start to finish. Remember that every astronomer started with a first look, and now you have the power to build the tool for that look yourself.