Advantages of making at least
part of your own telescope
1. Putting in the ‘sweat equity’ guarantees that
it won’t be a fly-by-night hobby you spend money on and then forget about
later; it gently forces you to learn a lot more about optics, seeing, and
astronomy.
2. You can make a much better telescope than you
can buy for anywhere near the same amount of money. No kidding!
3. You can tweak, or improve, an already-existing
telescope to eliminate problems or improve performance. (For example -
you can eliminate or reduce internal reflections on bright objects; you
can install a better focuser or finder; you can improve how the telescope
moves.)
4. There is no easier telescope on earth to use
than a home-made Dobsonian-mounted Newtonian reflector; and its images
are much brighter and crisper than any catadioptric telescope of its size.
(For example: there is no lengthy polar alignment; setting up the
telescope takes seconds, not minutes or hours.)
5. The mount can be absolutely rock-steady, unlike
the unsteady German equatorial tripod-mounted telescopes most beginners
buy. If you hit the side of a Dob very hard with your hand, the telescope
will shake for a second or two at most. However, if you so much as touch
a standard 'beginner scope' like a German equatorial mounted small refractor,
it is likely to vibrate for about 7 to 10 seconds, during which time you
can't see anything. When you push a Dob a bit to the right or down a bit to
follow a planet, then the scope will stay right there where you pushed it,
with no backlash or wobbling. That is not the case with your typical cheap,
wobbly commercial mount! Really steady equatorial mounts are very, very expensive
(many hundreds of dollars at least.)
6. If you choose to make the main mirror yourself,
you will have made, with your bare hands and no power tools, the most accurate
and precise large surface that humans can possibly make. The surface can
easily be accurate to better than 1/10 of a wavelength of green light,
over the entire surface. No microchip is so accurate for so large a surface.
7. Quality control at major telescope manufacturing
companies is ‘iffy’. Some commercial mirrors are good, and some are very
poor. It costs them too much to make the optics as good as you can do
on your own as a hobby, because of the amount of hand labor required for
perfection.
If you think you might like to make your own telescope optics, then
check out the National Capital Astronomers’ mirror-making workshop, held
every Friday evening from 6:30 to 9:30 PM (except for holidays and major
snowstorms) in the basement woodshop at the Chevy Chase Community Center
at McKinley Street and Connecticut Avenue, NW, in Washington, DC, near Chevy
Chase Circle. There is usually parking in the back. All of the materials
and instruction for a 6” mirror cost $70.00, not including aluminizing the
mirror. We can also test (free) or re-aluminize (small fee) your current
mirror. Contact Guy Brandenburg at gfbranden@earthlink.net or 202-262-4274
for more details.
last updated on July 26, 2003