Building Telescopes

John Dobson, founder of the Sidewalk Astronomers, invented a telescope design called the "Dobsonian" telescope. Though if you ask John, he'll tell you it's a "Sidewalk" telescope!

A Dobsonian "sidewalk" telescope

Each fall, John teaches courses in telescope making at the Randall Museum in San Francisco. On this site, you can learn what it's like to build your own scope, consult our "cheat sheet" for making your own mirror and telescope mount, and even check out the complete plans.

Telescope Making Classes in San Francisco

The next Telescope Making Class in San Francisco begins March 25, 2010.

Dave Frey, the class instructor, is the Current President of the San Francisco Amateur Astronomers and he learned his craft directly from John Dobson through the classes at the Randall Museum. Mr. Frey is an avid amateur astronomer, and has constructed many telescopes including a 20” portable Truss Tube reflector.


There is a registration fee for the class.  Additionally, the materials cost, including the mirror glass and plywood, will run approximately $300 to $400 depending on the size of the scope you decide to make.

For more details, check the Randall Museum's website.

Year-Round Telescope Making Classes

In the San Francisco Bay Area, you have another year-round option for personal instruction. The Chabot Space and Science Center in Oakland offers a Telescope Maker's Workshop every Friday night.

Do-It-Yourself: Plans and Instructions

You can also purchase printed plans and John Dobson's telescope making video directly from the Sidewalk Astronomers national website.

Other Telescope Making Resources

If you have a question about telescope making, or are looking for innovative design ideas, there are plenty of resources available in print and on the Internet.