My first Magazine Sky & Telescope - 03.2019 | Page 70

ASTRONOMER’S WORKBENCH by Jerry Oltion
Brent’s
Light
Bucket
You can make a telescope out
of practically anything.
I’M A BIG PROPONENT of what I call
“found object engineering.” There’s a
special kind of delight in creating some-
thing with stuff that’s been cluttering
up your shop for years, or in going to
the hardware store and wandering the
aisles in search of the perfect gadget
that can be repurposed for your project.
Washington ATM Brent Burton has
taken that concept to a perhaps ridicu-
lous extreme, building a telescope out
of a 5-gallon bucket, two 1-gallon buck-
ets, two soft drink cups, some plumbing
fixtures, and bungee cords.
We last saw Brent’s handiwork in
our May 2017 issue, when I wrote about
the beautiful wood-inlaid telescope and
hand-carved accessory tray he built.
This project occupies the opposite end of
the refinement spectrum, but it conveys
a certain beauty all its own: the beauty
of a project that’s simple, inexpensive,
functional, and unconventional.
Why did Brent build such a crazy
telescope? Besides the obvious desire
to build a “light bucket,” he says, “I
was always intrigued by small, portable
scopes. Like most people, however, I
didn’t have the money to go out and
custom machine individual parts to
build my own, so I decided to improvise
and build one using cheap building
materials that I could source from the
local hardware store.” Well, that plus
Olive Garden for the drink cups and his
u Left: Everything nestles inside the outer
bucket. Right: The scope parts laid out for as-
sembly show how simple a telescope can be.
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M A RCH 2 019 • SK Y & TELESCOPE
own garage for the outer bucket.
For the optics, he cannibalized a
4½-inch Orion StarBlast tabletop scope
that he picked up secondhand. He kept
the primary, secondary, and spider
assembly from the StarBlast and made
everything else himself.
The OTA is two 1-gallon buckets
with their open ends held together with
bungee cords. Brent cut the bottom out
of one to make the front opening and
mounted the primary mirror cell in the
bottom of the other. The mirror cell is
just a circle of medium-density fiber-
board held together with
thumbscrews and small
springs for collimation.
The helical focuser is made
from a toilet valve.
The altitude bearings
really make this scope.
They’re just plastic cups
from an Olive Garden res-
taurant with plastic rein-
forcing disks on the outer
ends. The threaded rod that
attaches them to the OTA
goes through the plastic
disks, the bottom of the
cups, and the lid on the top
that came with the cups.
I suspected that the cups
had to be filled with plaster
or something to keep them
from collapsing, but Brent
says that wasn’t neces-
sary. He did have to be careful with the
tension on the bungees that go over the
cups and provide friction in the altitude
direction, but he was able to find a sweet
spot that gave him the proper stiffness of
motion and didn’t crush the cups.
The lid of the big bucket becomes
the ground board, with hex-bolt heads
against the bottom of the “rocker
bucket” providing the right amount of
friction in azimuth. Brent had to cut a
flap in the side of the outer bucket for
the rear of the OTA to clear when aimed
at the horizon. He hinged the flap so
t Brent Burton holds what
might be the world’s most
portable “light bucket.”