Portable Modular Electrical
Discharge Machine for
Micro Hole Fabrication
This innovation relates to a low cost portable
electrical discharge machine (PEDM) for
effecting micro electrical discharge machining
at remote work sites. In electrical discharge
machining, a working electrode is juxtaposed
with an electro-conductive work-piece across
a machining gap. A pulsating DC voltage is
continuously applied to the machining gap to
produce successive electrical discharges across
the machining gap in order to remove material
from the work-piece. The machine comprises
a common machine frame adapted to house
an X-Y positioned apparatus and an electrode
assembly. The motion mechanism is controlled
by an EDM controller unit, consisting of an EDM
power controller, an EDM motion controller and
an XY position controller. Testing was done to
see the quality of micro holes fabricated with
different diameters of PEDM electrodes. The
effect of, material removal rate (MRR), electrode
wear ratio (EWR) and circularity were also
investigated using brass and stainless steel
work-pieces. These materials are commonly
used in engineering fields. The purpose of
using different electrode diameters, work-piece
materials, work-piece thicknesses, nominal
capacitance and feed rates were to investigate
the performance of the micro holes that were
produced. The results show that work-piece
thickness contributes the most to MRR and
EWR whereas electrode diameter is the most
significant parameter to the circularity of the
holes.
By Dr Azuddin Mamat
Figure 1 Portable Modular Electrical Discharge
Machine (EDM) for Micro Application
47