Page 25 - AMTDC Annual Report 2019-20flipbook

Various iterations on the length of the spindle, bearing span,
overhang, diameter of the spindle is done with constant load at the
overhanging positions and then deflection of the spindle is Incorporating the Best
calculated for each iteration.
Characteristics
Least deflection value is selected from the above iterations.
Geometric features corresponding to this deflection value are Orbital cutting works by combining
selected.
the best characteristics of chop,
Static analysis results provide how much the spindle shaft is oscillation, and transverse and increment
deflecting and ways to compensate the spindle deflection by cutters and able to cut samples quickly
means of material selection, spindle length, overhang and bearing without compromising cut quality by
span with proper bearing placements. Bearing span and spindle reducing the wheel-work nominal area of
overhang also plays a major role in maintaining the spindle contact. The minimization of blade contact
stiffness. Lesser the spindle overhang, larger will be the spindle time mitigates the effects of burn marks in
rigidity in support with the proper bearing placements. orbital cutting.

FEA analysis was done to ensure the spindle stiffness to Currently, the abrasive cutting
match the analytically calculated results. Required force will be machines are imported by the Indian
given with determined boundary conditions to provide the manufacturers at a huge cost that leads to
deflection results. an exceedingly high manufacturing cost.
The option is not financially suitable for the
In order to assess the performance capabilities of the developed small-scale industries to import the
prototype, the system was subjected to various tests. These include machines for the production purposes. The
geometric assessments, static rigidity, dynamic characteristics and orbital motion gives a substantial
cutting trials. Spindle rigidity test were conducted to determine the advantage for automatic abrasive cutting.
static characteristics of the spindle and spindle housing. Load cell is There are only very few companies in the
placed at the critical point (Spindle) of the machine under static world offering this technology. The
condition, then variable load will be applied between the spindle challenge is to manufacture these
and work holding chuck and the deflection was recorded at machines indigenously.
different point. The plot of load vs deflection was made and the
static rigidity characteristics were determined.

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AMTDC Annual Report | 2019-20