Sky & Telescope - December 2024 - 76

Astronomer's Workbench
The altitude bearings tuck in below
the solar panels and are painted black
to be unobtrusive. The rocker box is also
black for the same reason. Even during
the daytime, the mount fades into
the background and all you see is the
Hubble Space Telescope floating there
above the ground.
Lauren did have to widen the rocker
box to accept the wider scope, but that
was a short day's work. The scope was a
bit low to the ground in that mount, but
Lauren says, " More astro luck! I already
had the perfect base with an eyepiece
drawer built in. " That's the base she
built for the Zip Dob she bought from
Mel Bartels a few years ago (S&T: July
2021, p. 72). Resting on that short
table, the scope is at the perfect height
for observing while seated in a comfortable
chair.
Lauren says, " I didn't feel the need
to make a spider and secondary cage
when I could just rob it from the donor
scope. Instant upper OTA with another
cake pan for the edge! I love the scavenger
thing! "
One complication: The donor scope
was an 8″ f/7, which meant the 1.1″
secondary mirror was too small. An 8″
f/4 primary requires a secondary with
at least a 1.9″ minor axis. Also, the
donor secondary mount was a bear to
collimate. Fortunately, I had a spare 2″
secondary and some extra time, so I
made a lightweight mount for it, and we
swapped that onto the original spider.
(More on that secondary mount in an
upcoming column.)
Despite the lead weights down in the
bottom, the scope was still a touch topheavy.
Rather than add more weight,
Lauren bought a set of high-friction lidsupport
hinges, the kind that keep your
cedar chest lid from falling back down
and smashing your knuckles. They move
freely going up but provide adjustable
Lauren says, " Measure five times, cut once. "
She marked up the donor telescope's tube
to make really sure she was right before she
started cutting.
The moment of truth: Lauren cuts the old
tube to length.
pThe air vent " Hubbled up " beautifully to
make a convincing solar panel.
friction going down. Lauren set them to
counter the extra nose weight, and the
scope is now stable at all angles, even
with a heavy eyepiece.
With all that bling and the lead
weights at the bottom, I expected this
scope to be a hefty haul, but the base
weighs in at 18 pounds, and the scope
itself is only 23 lb. That's about the
same as a typical 8″ Dobsonian.
Lauren tested the scope in her backyard,
but I had the honor of joining her
for its first dark-sky outing. My first
impression as she lifted the scope out
of the car was astonishment at how
perfect it looked even close up. Then she
started assembling it, and my astonishment
continued to grow. The radio dish
attaches magnetically. The solar panels
slide onto exposed bolts and don't even
need nuts to secure them. Likewise for
the high-friction hinges. The scope set
up within minutes, and we were ready
to observe. Arcturus was the first bright
star visible in the twilight, so we turned
to that and . . . and . . . this thing is a
real telescope!
Since I made the primary mirror,
commenting on the crispness of the
view would be bragging. It took me
a while to even notice, to be honest,
because I couldn't stop giggling. I was
looking through the Hubble Space
Telescope! It was a dream come true.
A dream turned into reality thanks to
Lauren's imagination and dedication.
¢ Contributing Editor JERRY OLTION
thinks these may be the most beautiful
Hubble photos ever taken.
76 DECEMBER 2024 * SKY & TELESCOPE
Sky & Telescope - December 2024

Table of Contents for the Digital Edition of Sky & Telescope - December 2024
