“Here
is the prime condition of success: adopt every
improvement, have the best machinery, and know
the most about it.”
-
Anonymous
CNC Fast Hole EDM Drilling
Once considered
a last resort for drilling holes, Fast Hole EDM
(Electrical Discharge Machining) Drilling is quickly
becoming the standard method for producing small,
tight tolerance holes. It is an extremely cost
effective method for producing fast and accurate
holes into all sorts of conductive materials,
whether hard or soft. EDM drilling operates on
the principal of eroding material via the use
of electric energy. The work piece is submerged
in dielectric fluid and an electrode sends a spark
across the gap between the electrode and the work
piece, eroding the material, and the dielectric
fluid flushes the minute chips away.
There are many advantages of using EDM drilling
versus conventional drilling.
Drilling
on Curved, Spherical and Angled Surfaces |
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When
holes must be drilled on curved,
spherical or angled surfaces,
great difficulties arise with
conventional drilling. Drills
tend to walk off of such surfaces.
To prevent this, fixtures and
guide bushings must be used. With
EDM drilling, the electrode never
contacts the material being cut,
thus eliminating the tool pressure
normally experienced when drilling
on curved or angled surfaces.
EDM drilling is especially useful
for drilling straight or angled
holes in surgical or medical grade
tubing through one or both sides. |
Drilling
Hardened and Soft Materials |
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Some
materials are too hard to drill
using conventional methods. The
EDM machine drills through almost
any conductive material including
carbide and hardened steel. Some
soft metals can produce gummy
chips, leading to problems with
conventional drilling. Since the
chips are constantly flushed with
EDM drilling, speed, accuracy
and concentricity can be maintained. |
Deburring
and Finish |
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Deburring
holes drilled by conventional
methods can take longer than the
drilling. EDM drilling creates
no burrs. This burr-free drilling
saves time and labor, and is especially
crucial when difficult holes are
being drilled. In addition, surface
finishes are better with EDM drilling.
The smaller the hole, the more
important a smooth surface is.
By reducing the discharge energy,
holes can be polished. |
Deep
Hole Drilling |
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Drilling
small, deep holes with conventional
methods is often extremely difficult
if not impossible. EDM drilling
is often the only practical method
for producing such holes. As conventional
drills enter or exit, they can
break if torque is not carefully
controlled. Small broken drills
are often difficult to remove
from the work piece, and time
is wasted replacing broken drills
and parts may have to be scrapped.
With EDM drilling, torque conditions
do not exist since the electrode
never contacts the work piece. |
Machine Technology,
Inc. operates a Current EDM
Drilling machine. We primarily use it to drill
precise holes in medical and dental instruments,
but its uses are varied and include drilling holes
in turbine blades, fuel injectors, cutting tool
coolant holes, hardened punch ejector holes, plastic
mold vent holes, and starter holes for wire EDM.
If you require close tolerance, small holes, EDM
Drilling is the technology to utilize.
Machine
Technology Inc.’s CNC EDM Fast Hole Drilling
Machine:
(1)
Current EDM CT300 |
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Drills straight
or angled holes .004” Ø
to .256” Ø
Drilling depth up to 300 times
the electrode diameter
3 axes and 9 coordinate systems
with automatic part referencing
X-Axis Travel 12”, Y-Axis
Travel 8”, Z-Axis Travel
12”
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