6:30 - 9:30pm Friday night
Chevy Chase Community Center
5601 Connecticut Avenue, NW
Washington, DC
The NCA (National Capital Astronomers) has sponsored this telescope making workshop since, probably, the 1930's. The class been held in quite a few different locations around the DC metropolitan area, including at the American University's Physics Department. Jerry Schnall, who is retired from the U.S. Patent Office, took over the workshop about 1970. He has helped thousands of people since then to make telescopes of various sizes. Because of poor health, he asked to be relieved of the duty of running the workshop about 2 years ago. Guy Brandenburg, a math teacher in the DC Public School system, who had previously made two mirrors under Jerry's extremely competent and knowledgeable direction, volunteered to take over (with a lot of trepidation), and has been running the workshop, usually with Jerry's expert advice, ever since. Part of that job included organizing large numbers of very strong people so that we could move the lathe, the aluminizer, all the glass, all the grit, and all of the other odds and ends from the American University campus to the current location at the CCCC.
On any given Friday, there are likely to be from three to eight people working on various projects, at various stages of completion. 'Classes' are very informal, and you can start and finish a mirror or telescope at any time.
We only charge for materials!
- 4.25" -- $45
- 6" -- $70
- 8" -- $110
- There are larger sizes as well.
The price covers:
- A full-thickness, Pyrex mirror blank;
- All necessary grits and abrasives;
- Use of a tool for rough and fine grinding;
- Use of a pitch lap for polishing and figuring;
- Plenty of cheerful, patient assistance and instruction on grinding, polishing and figuring, as well as on the use of Ronchi and Foucault testing devices.
You should be able to get your mirror to within 1/4 wavefront error without too much difficulty, but many mirror-makers are successful at making them much better than that.
We also have an aluminizer to put the final, super-thin layer of reflective metal on your mirror. It costs a little extra - approximately $20 for an 8" mirror.
Some people buy their own kits from places like United Lens, Newport Glass, Willmann-Bell, or Dan Cassaro. You will generally find that it's cheaper from us, however.
We even have some basic woodworking machinery so that you can make much of the rest of your telescope in the same location, which was originally a woodworking shop. We even have a metal-working lathe, if you know what you are doing with one.
Quite a few people have come in to have us evaluate mirrors that they have purchased or that they have made themselves. Others have started a mirror on their own, but need a little advice on finishing things. Others want help on collimating (aligning) their commercial scopes. All of those requests are welcome, and are done for free, as a public service.
Contact Guy Brandenburg at gfbranden@earthlink.net or 202-262-4274.
Last Updated: Wednesday May 14, 2008 by Elizabeth Warner
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