Hours & Directions

MON, TUE: Closed

WED & THU : 10am - 5pm

FRI & SAT : 10am - 10pm

SUN : 10am - 5pm

Telescope Makers Workshop

"Surely the making and putting into use of a powerful astronomical telescope goes far toward properly orienting one’s self in the great scheme of things.”
- Russell Porter

I Can Build A Telescope?

Yes! Open to all ages, the Telescope Makers’ Workshop is an all-volunteer group committed to helping people build their own telescopes. Bring your interest and curiosity, and we’ll provide knowledge, enthusiasm, and advice to help you complete your telescope-making projects. No experience necessary.

Originally founded in 1930, the Telescope Makers’ Workshop has operated continuously since 1967, guiding hundreds of members in building their own telescopes. People of all ages and backgrounds have successfully completed fun-to-use instruments that provide hours of enjoyable observing of the night sky. Many have gone on to build more complex designs that are available to the amateur telescope maker today.


Where & When

The Telescope Makers’ Workshop is held every Friday night from 7pm - 10pm, excluding major holidays (e.g. Christmas Day and New Year's Day) that fall on Fridays. The Workshop is always closed on Memorial Day Weekend. Attendance every Friday night is not mandatory, and members work at their own pace.

The Workshop meets at Chabot Space & Science Center, 10000 Skyline Blvd., Oakland. Contact us for more specific details:

Contact:E-mail Richard Ozer or (510) 406-1914

What Kind Of Telescope Can I Build?

Most of our members build Newtonian telescopes on Dobsonian mounts. These telescopes and mounts are economical, fun to use, and relatively simple to build. Newtonian telescopes are much larger and perform much better than inexpensive department store telescopes, and building one is a terrific learning experience.

How Do I Build A Telescope Mirror?

The process of making a telescope mirror is very simple and requires no previous experience. With mirrors, a concave, spherical-shaped surface will reflect light from a star to a focused point. Two pieces of round glass are used, one of which is the mirror blank, the other the tool. By placing the mirror blank on top of the tool with a slurry of water and grinding compound between them, then pushing the mirror blank across the tool until it overhangs the bottom piece of glass by about one-third its diameter, the center area of the mirror blank is ground away faster than the edge. After about seven strokes, the tool and mirror blank are rotated a quarter turn from each other so another part of the mirror’s surface is ground. Thus a concave surface is ground out of the mirror blank.

Using successively finer grinding compound, and then a polishing compound, a polish is put on the surface of the glass. Fine-tuning of this surface, called figuring, puts the glass into the best shape for focusing starlight.

How Long Does It Take & How Much Does It Cost?

We charge no fees to attend the workshop. All of our instructors are unpaid volunteers. You will be expected to buy your own materials, including a mirror blank, a grinding tool, a rinse bucket, a spray bottle and paper towels. The workshop carries a small stock of mirror kits for sale at cost, and we can provide you with the names of other sources.

The typical 8”-diameter telescope mirror blank and tool cost under $150. A completed 8” telescope on a wooden Dobsonian mount can be built for under $300, compared to $400 - $900 for a commercially-made one.

It normally takes around forty hours of work to complete your first mirror. Some of this work is easier to do in the workshop, but much of it can be done at home, an hour or so at a time. Depending on your skills, you might spend a similar amount of time constructing a wooden mounting for your telescope with just a hammer, saw and screwdriver.

Who Builds A Telescope?

Since its start in 1967, the Telescope Makers’ Workshop has seen hundreds of members build their own telescopes. People of all ages and backgrounds have successfully completed fun-to-use instruments that provide hours of enjoyable observing of the night sky. Many have gone on to build more complex designs that are available to the amateur telescope maker today.

Telescopes built at the Telescope Makers’ Workshop have won awards for mechanical, design, and optical excellence at many of the major national telescope makers’ conferences, including the Riverside Telescope Makers Conference, Stellafane, and the Texas Star Party.

Many people build a telescope because it is less expensive than purchasing a commercial instrument. Parents often pair up with their children to do a family project, and school-aged children complete telescopes as a science fair project or homework assignment. Members sometimes come with just their curiosity and a desire to view the heavens with something they have made themselves. Whatever the reason, our members find advice and a sense of camaraderie among the many others who have found enjoyment in making their own telescope.