Blade Dressers
Analysis Of Economy
Consideration & Process Advantages
|
 |
| |
|
Introduction:
Blade dressers are basically conceived from the multi - point wheel
dressing
concept
- as an
extension
to the
areas
with a stringent control demand on quality & economy. The basic
advantages
which
have,
lead to
the
extensive
use of blade dressers are:
1. They
are very
economical
in
comparison
to
single -
point
dressers.
2.
Higher
form
retention
capability
compared
to
single
point
dressers.
3.
Minimum
in-process
service
attention
compared
to any
other
dressers
due to
their
self-wearing
property.
4. They
are
ideally
suited
for
optimum
dres'sing
condition
and in
turn for
optimum
grinding
conditions.
5.
Greater
flexibility
in
selection
from a
wide
range of
varities
of
dressers
to suit
different
grinding
wheel specifications and grinding conditions.
The following paragraphs offer in-depth study and detailed analysis
of the
above
attributes.
Economic
considerations:
Blade diamonds are composed of thin natural diamond needles which
are much
cheaper
than
larger
single
point
diamonds in direct consideration of weight basis. The impact ofthis
economy
will be
felt to
a
greater
extent
when we
try to replace the costlier chisel points, single points and
indexable
crowns
dressers.
Form retention capability :
A single point or a chisel point has a limitation that in certain
special
applications
like
dressing
of
wheels,
within
15 to 20 hours of running. The condition of the dresser tips
deteriorate
to such
a degree
that the
repeatability
of form
& related tolerances on the components are adversely affected. This
results
in the
necessity
to reset
the
dressers
with fresh cutting points.
Blade dressers are designed to utilize their full life span with
minimum
deterioration
of form
and
tolerances.
Fig. 1 (page 26) gives certain typical examples or areas where
certain
steep
angles
and
sharp
internal
corners
are
effectively traced with precision blades in comparison to ordinary
single
point
dressers
and
ordinary
blade
dressers.
Minimum in-process service attention:
Normally, when a single point or a chisel point dresser is mounted,
the
machinist
has to
"watch"
for a
number
of
defects on the component.
1.
"Glazing"
of the
wheel
due to
"blunting"
of
diamonds.
2. Loss
of form
&
profiles.
3.
"Breaking
of wheel
corners:
4.
Appearance
of "unstraightness"
due to
varying
load
conditions
on the
dressers.
Blade dressers have been developed on the "fix and forget"
principal
- a
concept
of the
right
choice
of
dresser
for an
operation - when the next attention of the machines is
warranted
only
when the
dresser
is fully
used up.
Optimised Conditions of the grinding wheel:
Modern grinding technology has facilities to optimise
grinding
process
to the
barest
minimum
operational
cost-
provided. The very starting point of the operation, namely
dressing,
is
optimised.
A proper
dressing
demands
the
following conditions on the grinding wheel surface.
1. A
pure
abrasive
action -
no
"rubbing"
action.
2.
Properfracture
of
individual
grains
to
expose
maximum abrasive area for grinding.
3.
Minimum
"filling"
of
bonding
cavities
on the
wheel
surface
to
minimise
friction
during
grinding
operation.
4.
Minimum
"grain
pull
out".
Flexibility
in
selection:
Unlike single point dressers which are more or less independent
of the
grinding
wheel
specifications
or
conditions
(except for the weight in carats), blade dressers need to be
selected
with due
considerations
to the
grinding
wheel
specification and conditions of dressing.
Conclusion:
Blade dressers have been developed over the last two decades
through
extensive
field
trials
with
renowned
engineering industries. The benefits derived have been passed
on to
the
several
users,
through substantial reduction in their tool costs.
|
|
|
|
|
|
===
