Model
Construction
Models are constructed by our highly skilled
model maker in transparent polyacrylate in such
a way that the inside surface of the model reflects
the inside surface of the full scale chute,
including the wear liners.
From the drawings provided, the models are first
developed by computer in 3D to provide the necessary
information for construction in polyacrylate.
The joins are all calculated by this process
and are carefully mitred and glued at the appropriate
angle. This type of construction differs considerably
from fabrication in steel, where thickness is
small in relation to overall scale. Typical
thicknesses of plastic used are 2, 3 and 6 mm,
and the construction techniques have more in
common with cabinetmaking than steel fabrication.
The use of fully mitred joins ensures that there
are no discontinuities at the joins, no matter
how complex they are.
Reinforcing and mounting geometry is tailored
to suit plastic fabrication. Much of the structural
reinforcement in the steel fabrication can be
eliminated in the scale model, but flanges between
components of an assembly are dimensioned so
as to provide suitable stiffness in the model.
Curved surfaces are calculated and formed by
heat treatment using turned and occasionally
hand-formed or CNC templates, with careful allowance
for anisotropic effects during forming. As with
all other joins, the edges of curved components
are mitred to fit their mating parts.
The end result of this process is a model
that provides unmatched accuracy of the geometry
of the full scale chute as well as providing
a clear view of the internal flows and appropriate
structural rigidity.
Belts
Belts are sized to scale for the application. BSM have developed specialised
belts for scale model purposes that are capable
of duplicating the troughing angles of full scale
belts. Conventional belts on small conveyors are
not capable accurately duplicating troughing angles
due to their inherent stiffness. BSM’s developments
have overcome this hurdle.
The conveyors used for modelling are slider bed
conveyors. These are the only type suitable for
modelling at the scales used. For any particular
application, the slider bed is tailor made to
duplicate the idler configuration in the full
scale system.
Belt speeds are controlled by variable speed drives
and are set to match the scale equivalent of the
full scale belt speed, according to the scaling
rules used.
This attention to detail provides unequalled accuracy
of simulation of full scale geometry.
Head Pulleys
The head pulleys used in models are constructed
precisely to scale, allowing for the lagging
on the pulley. The width of the pulley is also
to scale, so that the pulley fits inside the
head box, duplicating the full scale situation.
There is no need to have cut outs in head box
to allow for over-width head pulleys as was
the case in the early days of the technology.
The vertical position of the head pulley is
set in relation to the slider bed so as to accurately
mimic the transition geometry of the full scale
conveyor. This provides the most accurate possible
simulation of the material trajectory.
Test Facility
Our dedicated test facility comprises 300 square
metres of floor space. Three separate circuits
can be run any one time. All fabrication and
testing is provided on-site. Ancillary equipment
such as screens is fabricated on site to suit
the application.
The test facility is located adjacent to some
of South Western Australia’s premier tourist
attractions and there is a large range of accommodation
options available for visitors, some within
easy walking distance.
http://www.pembertonvisitor.com.au/
Continuous improvement
BSM is constantly seeking to improve the modelling
process. The innovations in the existing process
will be apparent to anyone experienced in modelling
and there are constant improvements to the overall
modelling process being developed on an ongoing
basis.
