How I got started building
telescopes and making mirrors
Well, I grew up helping my dad build all kinds of strange and useful
things in the woods in the northern lower peninsula of Michigan, a very
beautiful state I must add (at least once you get north of Lansing a
bit). The sky was quite dark and transparent on many
mosquito-laden summer nights,
and one night I decided, since I liked science, that I should know the
sky
and constellations.
Enter a pair of binoculars. I found the Andromeda galaxy, M13,
lots of globulars in Opiuchus, the Lagoon Nebula, and all the open
clusters and star clouds of the Milky Way through Sagittarius and
Scutum. I borrowed a neighbor's 60mm refractor and the moon
looked great. I remember
observing Jupiter with this scope and with the 3" or 4" reflector that
my
parents bought for me soon after. From our greenhouse I watched
the moons change
position
every night, but I can't remember if I saw cloud detail on the Jovian
disk
or not.
I needed a better telescope. After looking through
countless ads in Astronomy Magazine, I realized that most in the size
that I wanted (8") were too expensive. Thus, the only solution
was to build one.
I think around this time I picked up a subscription to Telescope
Making,
at issue 36 (Spring, 1989). (Sadly this magazine ended at issue
46,
in the winter of 1991.) Somewhere in this eye-opening publication
I
got the idea that I could make my own primary mirror and my own
telescope.
My parents got me an 8" mirror kit from Willmann-Bell, which I think
cost around $100 at the time. A large wooden spool that once held
power
cable for power lines became my grinding stand, and I still have the
plywood
board that served to hold the mirror/tool and the bucket I washed them
in
countless times. There is a lot of pyrex dust in the woods around
the
old house.
I can't remember what focal ratio I went for first, but I ended up
regrinding to a different one and polishing the mirror again with what
I now suspect was a VERY hard pitch lap. Wilmann-Bell even sent
me some more pitch in an attempt to help me out in my struggle. I
didn't have any contacts to ask questions of, and I was having no luck
changing the figure of the
mirror. Somehow for one fleeting moment I got a sphere. It
probably
would have been best to quit here, but I persevered and tried to
parabolize,
with poor results.
A move to Cincinnati in 1990 left the mirror and tool in a box for a
while. I think I started working on them again for a bit, but
they were soon packed away again. I was given a scope containing
a 5.25" F/8.8 mirror. When I removed the mirror, the remains of a
dead mouse were lying
on it. I built
a Dob using this
mirror, but its performance was incredibly bad. Stars didn't
really focus.
I disassembled the scope and put the mirror in a box. (I
would
find out later that the glass had been etched by something, and then I
would refigure it.)
After frustrations with two mirrors, I capitulated and bought an 8" F/6
mirror from Meade, and built another
Dob. This scope was used extensively, and I got to see most
of the Messier list and good detail on the planets.
One day I was in the basement of the Cincinnati
Astronomical Society building (since demolished, sadly, and another
building
put in its place) and came upon a large metal tube rusting.
Inside
was a plate glass primary mirror and a secondary. I brought it up
at
a meeting, and the club was happy to have a high-school student
interested
in buying a piece of junk rusting in the basement. I still
remember
driving home on a cold winter day with my new telescope parts all over
the place
in my car. It was a good day.
Months later I had completed my version #1 of my 10" F/6.8 telescope,
named Messier
10.
I even wrote an article about building it for the club
newsletter,
the Sidereal Messenger. It had 15 pounds of lead counterweight in
the
back, but I didn't care. It was hauled back to Michigan and
provided
great views. Then came high school graduation, and four years of
college.
I joined the Rose-Hulman Astronomical Society and became
president
for a couple years. We played with SCTs and CCD cameras, and
watched comets Hyukatake and Hale-Bopp glide across the sky.
Next came graduate school, membership in the Astronomical Society at
the University of Illinois (UIAS),
and a trip to Astrofest 1998. I took my 10" scope and sneezed for
two
days straight due to hay fever, but I didn't care. I was
surrounded
by 800+ people and nearly as many telescopes, and Jupiter looked great
through
my modest scope. I made sketches.
I won an award in the telescope contest. Another trip to
Astrofest
a year or two later got me thinking about finishing the project that
was
sitting in the closet - the 8" mirror, now ground to approximatey F/4.
When I bought a house in 2001, it needed work and I spent a year
and a half fixing it up and creating a workshop space in the basement.
In late 2002 the house
work was mostly done and I realized I now had a work space that I had
full
control
of, and some small bits of pitch in the kitchen were fine with me.
Mirror grinding began on December 26th, 2002 and was finished
in
March. I had completed a very good 8" F/3.9 mirror. I built
a
scope around it and first light occurred in April of 2003. I
stayed
up late cruising the Milky Way, waiting for Mars to rise. When I
saw
surface features, I knew that I had finished something useful, and I
will never sell it.
Since the beginning of 2003 (it is now early 2008) I have ground or
refigured ~90 mirrors, ranging in size from 4.25" F/4.5 to 32"
F/4. This includes four
Cassegrain scopes (12.5", 14.25", 16.25" classicals and a 28" RC), for
myself, a
friend, for the Champaign-Urbana
Astronomical
Society (CUAS), and for a very motivated friend,
respectively. I've
also done some work
on flats, including fixing/making small and large elliptical diagonals
up to 8.25" m.a.
for Newtonian
scopes. I seem to have a knack for testing and figuring
high-quality optics, and I enjoy doing it. I really like taking
precise measurements, so testing optics is perfect for me.
Needless to say, I will
be making optics for a long time to
come. It gives me great satisfaction to make or fix a mirror for
a friend or client (clients usually become friends), and then to watch
them use it up to its full potential.
I was the president of the Champaign-Urbana Astronomical
Society for 2006 and 2007. I also enjoy giving talks on
mirror-making
or telescope
making at meetings, star parties, etc.
My talks and articles are listed here.