| F CODE | Coded number, following the F address, that specifies a feedrate or an
amount of feed relative to a workpiece.
|
| FACE | To machine a flat surface, as in the end of a
shaft in the lathe. The operation is known as facing
|
| FACE MILLING | Milling a large flat surface with a
milling cutter that operates in a plane that is at right
angles to its axis.
|
| FACEPLATE | A large circular plate with slots and holes
for mounting the workpiece to be machined. It is
attached to the headstock of a lathe.
|
| FACING | The process of making a flat or smooth
surface (usually the end) on a piece of stock or
material.
|
| FATIGUE | The effect on certain materials, especially
metals, undergoing repeated stresses.
|
| FEED
ENGAGE
POINT | The
point
where
the
motion
of
the
Z
axis
changes
from
rapid
traverse
to
a
programmed
feed
(usually
referred
to
as
the R dimension)
|
| FEED
FUNCTION | The
relative
motion
between
the
tool
or
instrument
and
the
work
due
to
motion
of
the
programmed
axis
or
axes
|
| FEED | The rate of travel of a cutting tool across or
into the work-, expressed in inches per minute or in
inches per revolution.
|
| FEED FUNCTION | Controlling the tool feedrate.
|
| FEED HOLD | Temporarily stopping feed during program execution.
|
| FEED MECHANISM | The mechanism, often automatic.
which controls the advancing movement (feed) of the
cutting tools used in machines.
|
| FEED PER MINUTE | Cutting feed in which the distance the tool is to advance is specified per minute.
|
| FEED PER REVOLUTION | Cutting feed in which the distance the tool is to advance is specified per
spindle rotation.
|
| FEED RATE | Refers to the speed at which a cutter can advance against a workpiece.
|
| FEEDBACK
CONTROL | Action
in
which
a
measured
variable
is
compared
to
its
desired
value,
with
a
function
of
the
resulting
error
signal
used
as
a
corrective
command
|
| FEEDBACK
DEVICE | An
element
of
a
control
system
which
converts
linear
or
rotary
motion
to
an
electrical
signal
for
comparison
to
the
input
signal.
E.g.,
resolver,
encoder,
inductosyn
|
| FEEDBACK
LOOP | A
closed
signal
path,
in
which
outputs
are
compared
with
desired
values
to
obtain
corrective
command
|
| FEEDBACK
RESOLUTION | The
smallest
increment
of
dimension
that
the
feedback
device
can
distinguish
and
reproduce
as
an
electrical
output
|
| FEEDBACK
SIGNAL | The
measurement
signal
indicating
the
value
of
a
directly
controlled
variable,
which
is
compared
with
a
setpoint
to
generate
a
correction
command
|
| FEEDBACK | The
signal
or
data
fed
back
to
a
commanding
unit
from
a
controlled
machine
or
process
to
denote
its
response
to
the
command
signal.
The
signal
representing
the
difference
between
actual
response
and
desired
response
that
is
used
by
the
commanding
unit
to
improve
performance
of
the
controlled
machine
or
process
|
| FEEDFORWARD
(ANTICIPATORY)
CONTROL | Action
in
which
information
concerning
upstream
conditions
is
converted
into
corrective
ccnmands
to
minimize
the
effect
of
the
disturbances
|
| FEEDRATE
BY-PASS | A
function
directing
the
control
system
to
ignore
programmed
feedrate
and
substitute
selected
operational
rate
|
| FEEDRATE
NUMBER | A
coded
number
read
frcm
the
tape
which
described
the
feedrate
function.
Usually
denoted
as
the F word
|
| FEEDRATE
OVERRIDE | A
variable
manual
control
function
directing
the
control
system
to
reduce
or
increase
the
programmed
feedrate
|
| FEEDRATE CLAMP BASED ON ARC RADIUS | Automatically clamping a circular cutting feedrate so that an arc radius error
due to post-interpolation acceleration/deceleration and servo delay does not
exceed an allowable error.
|
| FEMALE PART | A concave piece of equipment which
receives a mating male (convex) part.
|
| FERROUS | A metal alloy in which iron is the major
ingredient.
|
| FIGURE COPY | Repetitive machining performed by rotating a figure specified by a subprogram,
or shifting it in parallel.
|
| FILE | Named set that is stored or processed as a single unit.
|
| FILE HEADING | Specifying a file that is to be manipulated (for example, to be input to the
CNC).
|
| FILE TEST | A test for hardness in which a corner of a
file is run across the piece of metal being tested. The hardness is shown by the dent the file makes.
|
| FILLET | A curved surface connecting two surfaces that
form an angle.
|
| FINAL
CONTROL
ELEMENT | A
valve,
motor,
or
other
device
which
directly changes
the
value
of
the
manipulated
variable
|
| FIRMWARE | Programmes
or
instructions
stored
in
read
only
memories
|
| FIRST
GENERATION | 1.
In
the
NC
industry,
the
period
of
technology
associated
with
vacuum
tubes
and
stepping
switches.
2.
The
period
of
technology
in
computer
design
utilizing
vacuum
tubes,
electronics,
off-line
storage
on
drum
or
disc,
and
programming
in
machine
language
|
| FISHTAIL | A common name for the center gage. It is
used to set thread cutting tools and has scales on it for determining the number of threads per inch.
|
| FITTING | Any small part used in aircraft construction.
|
| FIXED
BLOCK
FORMAT | A
format
in
which
the
number
and
sequence
of
words
and
characters
appearing
in
successive
blocks
is
constant
|
| FIXED
HEADS | Rigidly
mounted
reading
and
writing
transducers
on
bulk
memory
devices
|
| FIXED
SEQUENCE
FORMAT | A
means
of
identifying
a
word
by
its
location
in
a
Wbrds
must
be
presented
in
a
specific
order
and
all
block
of
information.
possible
words
preceding
the
last
desired
word
must
be
present
in
the
block
|
| FIXTURE | A production work-holding device used for
machining duplicate workplaces. Although the term
is used interchangeably with a jig, a fixture is not
designed to guide the cutting tools as the jig does.
|
| FLANGE | A relatively thin rim around a part.
|
| FLASH | A thin edge of metal formed at the parting line
of a casting or forging where it is forced out between
the edges of the form or die.
|
| FLIP
FLOP | A
bi-stable
device.
states.
A
device
capable
of
assuming
two
stable
A
bi-stable
device
which
may
assume
a
given
stable
state
depending
upon
the
pulse
history
of
one
or
more
input
points
and
having
one
or
more
output
points. The
device
is
capable
of
storing
a
bit
of
information; controlling
gates;
etc.
A
toggle.
|
| FLOATING REFERENCE POSITION RETURN | Returning a tool to a floating reference position. The floating reference position
serves as a reference position for a specified mechanical operation. It is
not necessarily a fixed position. It may be relocated.
|
| FLOPPY
DISK | A
flexible
disk
used
for
storing
information
|
| FLOW
CHART | A
graphical
representation
of
a
problem
or
system
in
which
interconnected
symbols
are
used
to
represent
operations,
data,
flow,
and
equipment
|
| FLUIDICS | The
technique
of
control
that
uses
only
a
fluid
as
the
controlling
medium.
All
control
is
performed
without
moving
elements.
|
| FLUTE | The groove in a cutting tool which provides a
cutting edge and a space for the chips to escape and
permits the cutting fluids to reach the cutting edges
|
| FLY CUTTER | A single-point cutter mounted on a bar in
a fly cutter holder or a fly cutter arbor- used for
special applications for which a milling cutter is not
available
|
| FMS | Flexible Manufacturing System
|
| FOLLOWER REST | A support for long, slender work
turned in the lathe. It is mounted on the carriage,
travels close to and with the cutting tool, and keeps
the work from springing away.
|
| FOOTSTOCK | Part of an indexing, attachment which has
a center and serves the same purpose as the tail stock
of a lathe.
|
| FORBIDDEN AREA | Area where a tool is forbidden to enter.
|
| FORCE FIT | A fitting which one part is forced of
pressed into another to form a single unit. There are
different classes of force fits depending on standard
limits between mating parts.
|
| FOREGROUND
PROCESSING | Execution
of
real-time
or
high
priority
programmes,
which
can
pre-empt
the
use
of
computing
facilities
|
| FORGE | To form or shape heated metal by hammering.
Also, the name of the unit used for heating metal, as
the blacksmith’s forge.
|
| FORMAT
CLASSIFICATION | A
means,
usually
in
an
abbreviated
notation,
by
which
the
motions,
dimensional
data,
type
of
control
system,
number
of
digits,
auxiliary
functions,
etc.
for
a
particular
system
can
be
denoted
|
| FORMAT
DETAIL | Describes
specifically
which
words
of
what
length
are
used
by
a
specific
system
in
the
format
classification
|
| FORMAT | The
arrangement
of
data
|
| FORMAT GUIDANCE | Displaying program creation guidance in a specified format on the screen.
|
| FORMED CUTTERS | Milling cutters which will produce
shaped surfaces with a single cut’, and so designed
that they may be sharpened without. changing their
outline or shape.
|
| FORMING TOOL | Tool ground to a desired shape to
reproduce this shape on the workpiece.
|
| FORTRAN | Acronym
for
Formula
Translator,
an
algebraic
procedure
oriented
computer
language
designed
to
solve
arithmetic
and
logic
programmes
|
| FOURTH
GENERATION | In
the
NC
industry,
the
change
in
technology
of
control
logic
to
include
computer
architecture.
|
| FREE CUT | An additional cut with no advancement of
depth.
|
| FREE CUTTING STEEL | Bar stock containing a high
percentage of sulfur, making it very easy to machine.
Also known as Bessemer screw stock.
|
| FREE FIT | A class of fit intended for use where
accuracy is not essential, or where large temperature
variations are likely to be encountered, or both
conditions
|
| FREQUENCY
RESPONSE
ANALYSIS | A
method
of
analyzing
systems
based
on
introducing
cyclic
inputs
and
measuring
the
resulting
output
at
various
frequencies
|
| FREQUENCY
RESPONSE
CHARACTERISTIC | The
amplitude
and
phase
relation
between
steady
state
sinusoidal
inputs
and
the
resulting
sinusoidal
outputs
|
| FULCRUM | The point or support on which a lever
turns.
|
| FULL
DUPLEX | Allows
the
simultaneous
transmission
of
information
in
both directions
|
| FULL
PROPORTIONAL
SERVO | A
system
with
complete
proportionality
between
output
and
input
|
| FULL
RANGE
FLOATING
ZERO | A
characteristic
of
a
numerical
machine
tool control
permitting
the
zero
point
on
an
axis
to
be
shifted
readily
over
a specified
range. The
control
retains
information
on
the
location
of permanent zero
|
| FUNCTION FOR SWITCHING BETWEEN DIAMETER AND RADIUS PROGRAMMING | Preparatory function for switching between diameter and radius specifications.
|
| FUNCTION KEY | Key on the MDI keyboard used to select a screen to be displayed on the CNC
display unit. Function keys are classified by function.
|