  We present a new procedure for the construction of parabolic mirrors using
low cost materials. We build a spinning system composed of nylon threads, fish
hooks and a plastic bucket. We pour liquid plaster into the bucket and set it
in constant rotational motion relative to the earth. A liquid substance assumes
a parabolic profile when spinning at constant angular velocity relative to an
inertial frame under the influence of an uniform vertical gravitational field.
By keeping the bucket under rotation for a long time, the plaster solidifies
into a parabolic format. We utilize this solidified plaster paraboloid as a
model to construct a counter-mould of glass fibre and resin. Over this
counter-mould it is placed stretched laminated foil and then it is poured thick
plaster over it. In this way it is obtained a parabolic mirror made of
laminated foil and plaster. Our only objective here is to present a new method
for the construction of parabolic mirror using low cost materials. This allows
further exploration of this procedure by teachers and students either in
high-schools or in universities.
