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The Cuttlefish Drive: a low-budget ROV propulsion system. |
Category: Machinery/Equipment |
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Mark Langford
Beccles, Suffolk, GB
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Page Views: 1,297
Votes: 10
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Entered: 07/13/2008
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Every
submersible
remotely-operated
vehicle
(ROV)
has
weaknesses.
Everything
that
pierces
the
hull
(door,
cable)
is
a
potential
leak,
and
if
something
must
both
pierce
the
hull
and
move
at
the
same
time,
the
potential
for
leakage
is
multiplied.
This
entry
is
a
drive
system
that
eliminates
the
need
for
drive-shafts
to
pierce
the
hull
of
an
ROV,
and
also
removes
the
very
real
possibility
of
rotating
impellers
getting
tangled
or
jammed
by
underwater
plants
or
hanging
lines.
It
could
also
give
rise
to
vehicles
that
have
a
much
less
damaging
effect
on
the
habitats
they
are
used
to
investigate,
because
of
the
lack
of
a
"wash",
and
the
lack
of
rotating
impellers
will
reduce
the
risk
of
injuring
animals
the
Cuttlefish
Drive
encounters.
A
rotating
shaft
needs
to
pierce
the
hull
completely,
working
through
a
hole
in
the
hull.
On
the
other
hand,
a
reciprocating
motion
(up-and-down)
could
work
through
a
flexible,
waterproof
membrane
which
did
could
be
fixed
firmly
around
any
moving
parts
without
ripping.
However,
flexible
membranes
have
a
limited
life,
but
magnets
don't,
and
magnets
can
act
through
any
non-magnetic
materials
without
restriction.
Make
the
hull
rigid,
but
non-magnetic,
and
these
issues
are
eliminated.
The
Cuttlefish
Drive
is
intended
to
open
up
the
use
of
ROVs
to
those
with
a
lower
budget,
such
as
schools
and
hobbyists.
The
working
elements
of
the
ROV
are
enclosed
within
a
single,
watertight
hull.
This
could
be
a
simple
as
a
short
length
of
plastic
drainpipe.
There
is
a
rotating
cam-shaft
along
each
side
of
the
hull,
which
operates
a
row
of
short
levers
in
a
rippling,
sinusoidal
pattern.
Each
lever
has
a
powerful
magnet
at
the
end
closest
to
the
hull.
Outside
the
hull,
there
is
a
second
row
of
levers,
again
with
magnets
on
the
ends
closest
to
the
hull.
The
levers
extend
beyond
the
pivot-point,
and
there
is
a
continuous
flexible
membrane
between
the
levers.
When
the
cam-shaft
inside
the
hull
rotates,
the
magnets
moving
inside
the
hull
attract
the
magnets
outside
the
hull.
Thus,
the
external
levers
move
the
membrane
in
a
manner
similar
to
the
swimming
surface
of
a
cuttlefish
or
some
nudibranches.
Steering
is
achieved
by
running
each
membrane
at
a
different
speed,
and
the
cam-shafts
can
also
be
reversed.
Depth
control
would
be
achieved
by
having
the
first
and
last
ribs
of
the
membranes
under
independent
control,
acting
in
a
manner
similar
to
an
aircraft’s
ailerons.
These
independent
ribs
could
also
be
used
to
induce
rolling
or
banking
to
the
ROV’s
motion,
increasing
manoeuvrability.
Further
work
could
be
done
replacing
the
cam-shafts
with
independently-controlled
servo-motors,
or
electromagnetic
actuators,
but
these
would
add
complexity
and
cost
to
a
design
intended
to
reduce
both.
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Meet the Entrant, Mark Langford
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Profession: Educator |
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My Website: http://www.instructables.com/member/kiteman... |
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Number of times entering contest previously: 0
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Design Tools:
Pencil and Paper
Physical models
Image rendering software
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Mark's favorite design tool:
I can't afford professional design software, and I've had no real training in design, so...
I didn't really design, as such - I had an image in my head, and I played with the wood and bamboo until they fit the image.
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Mark's hobbies and activities:
I'm a Maker. Check my contact details to see the mix of things I make. This entry is a modification (and re-naming) of one of my recent projects.
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What role does Mark believe product design plays in creating a better future?
I think "design" will stop being the exclusive province of professional designers. More and more people are getting access to professional-quality design and manufacturing tools, so "mass production" could become a thing of the past - individuals could design anything they want, make it (or have it made) and pass the designs on for others to use. That is the promise and fun of sites like instructables.com
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