Australian Sky & Telescope - 04.2019

(Darren Dugan) #1

72 AUSTRALIAN SKY & TELESCOPE April 2019


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
something with stuff that’s been
cluttering up your shed 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.
Brent Burton has taken that concept
to a perhaps ridiculous extreme, building
a scope out of a 20-litre bucket, two
4-litre buckets, two soft drink cups, some
plumbing fixtures and bungee cords.
We last saw Brent’s handiwork in
ourJuly2017issue,whenIwroteabout
thebeautifulwood-inlaidtelescopeand
hand-carved accessory tray he built. His
newprojectoccupiestheoppositeendof
the refinement spectrum.
WhydidBrentbuildsuchacrazy
telescope?“Iwasalwaysintriguedby
small,portablescopes.Likemostpeople,
however,Ididn’thavethemoneytogo
out and custom machine individual
partstobuildmyown,soIdecidedto
improvise and build one using cheap
buildingmaterialsthatIcouldsource
from the local hardware store.”
Fortheoptics,hecannibaliseda
secondhand 114-mm Orion StarBlast
tabletop scope. He kept the primary,
secondary and spider assembly from
theStarBlastandmadeeverythingelse
himself.
TheOTAistwo4-litrebucketswith
theiropenendsheldtogetherwith
bungee cords. Brent cut the bottom
outofonetomakethefrontopening
andmountedtheprimarymirror
cellinthebottomoftheother.The
mirrorcellisjustacircleofmedium-
density fibreboard held together with

BRENT BURTON (4)

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 with
plastic reinforcing 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. Brent says 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
properstiffnessofmotionanddidn’t
crush the cups.
The lid of the big bucket becomes
thegroundboard,withhex-boltheads
againstthebottomofthe‘rocker
bucket’providingtherightamountof
friction in azimuth. Brent had to cut a
flap in the side of the outer bucket for
therearoftheOTAtoclearwhenaimed
atthehorizon.Hehingedtheflapso
nothing would fall out during transport.
Brentsaysthescopetookhimabout
amonthtobuild:“Anhourafterwork
andafewhoursontheweekendhere
and there.”
Howwelldoesitwork?“Surprisingly,
not too bad. Although it works as

alarger-footprinttabletopscope,I
actuallyenjoyedtakingtheOTAby
itselfandusingitasaskysweeperwhile
sitting in a chair.” The scope doesn’t
needafinder,sinceit’ssuchawide-field
scope on its own.
For more information, contact Brent
[email protected].

■Contributing EditorJERRY OLTION
sometimes uses buckets as secondary
cages, too.

Brent Burton holds what might be the
world’s most portable ‘light bucket’.

XLeft: Everything nestles inside the outer
bucket. Right: The scope parts laid out for
assembly show how simple a telescope can be.
Free download pdf