Sky & Telescope - June 2022 - 74

ASTRONOMER'S WORKBENCH by Jerry Oltion
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Cardboard, tape, and glue can do some amazing things.
Drew Sorenson built the rocker box for his
travel scope out of cardboard. For the azimuth
adjustment he simply skidded the box around
on the ground.
audacious one I've ever heard of was the
watermelon scope presented at Stellafane
in 1991. That's right: the OTA was
a watermelon. And it worked . . . at least
for a little while.
In our April issue I wrote about a
travel scope that I'd built, based on
an elegant design by Dutch ATM Roel
Weijenberg (S&T: Oct. 2016, p. 72).
That led to a discussion of travel scopes
with Drew Sorenson, whose pipe-fitting
pier mounts I featured in our May 2020
issue. Drew mentioned that he had once
taken just the mirrors and hardware
with him on a trip to Mexico and had
built the entire telescope on site - out
of cardboard boxes.
This I had to see! Fortunately, Drew
had a photo (left).
It's anything but elegant. Yet someTHOSE
OF YOU WHO have been reading
this column for the last few years have
a pretty good idea of my design philosophy:
It doesn't have to be pretty so long
as it works. The question is, how far can
you take that philosophy before it quite
literally falls apart at the seams? Much,
much farther than you might think.
Over the years I've been repeatedly
amazed at what people have built and
called a telescope. Probably the most
74 JUNE 2022 * SKY & TELESCOPE
how it is elegant, in a primal sort of
way. I don't even need to
describe how he built it
or how it works; you can
see that just by looking
at it. Drew reports that
it showed the night sky
quite well, and the view
impressed his family and
their neighbors as well as
any factory-built scope
would have. A line of
people queued up to look
through it every night.
That wasn't Drew's
only travel scope. He built
another one for a later
trip to Texas to visit more
family. This time he took
only the mirrors and fabricated
everything else out
of cardboard, including
a curved secondary mount. The box he
was using for material was too small
to make the entire OTA in one piece,
so he spliced two pieces together in
the middle. The focuser was a simple
push-pull cardboard tube. Drew didn't
bother to construct a rocker box for
this one; he just propped the scope
against a chair and scooted the bottom
around for aim.
Both scopes functioned well enough
to provide great views for the duration
of his visits, and Drew had no worries
about the OTA surviving the trip. He
simply recycled the pieces when he was
done with them.
Oregon ATM David Davis had a
similar need one year at the Oregon
Star Party. He had just finished a
16-inch f/3 ultra-thin (3
/8-inch thick!)
mirror he affectionately called " Fuzzy, "
and he needed an OTA to show what
it could do. While looking around his
shop for inspiration, his gaze fell on a
sheet of pink insulation foam. Using a
handheld power saw, he
cut the foam into strips
with angled edges, taped
them together with blue
gaffer's tape, and stuck
them in a wooden flower
planter. He nudged them
into an acceptable circle,
then filled the edge gaps
with spray foam, which
also stiffened up the OTA
quite well.
He attached a focuser
to a thin board, which he
then bolted through the
foam and did the same for
a Telrad finder. The rocker
Drew's 4-inch f/10 travel
scope was just a cardboard
OTA. He leaned it against a
chair for aiming.
DREW SORENSON (2)
Sky & Telescope - June 2022

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