CNC Glossary

[CNCadmin]

I'm going to make a new page of CNC Glossary words. So if you have definitions of words please mail them to me @ paul@cnczone.com I will add the words to the page and provide a new link.

[Chunky]

Originally Posted by CNCadmin I'm going to make a new page of CNC Glossary words. So if you have definitions of words please mail them to me @ paul@cnczone.com I will add the words to the page and provide a new link.

2d versus 3d versus 2-1/2d

[DAB_Design]

2d = a part is cut at the same Z depth at all times. Think of a mouse pad, or the outside of a CD. To cut these shapes, Z axis would only need to move to one depth while X and Y are stationary.

2 1/2D = a part is cut at different Z depths. But when Z moves, X and Y are stationary. Think of a set of stairs. Mill one step, stop X and Y - raise or lower Z, mill next step.

3D - A part that require constant 3 axis movement. Think of milling the outline of the threads on a baseball. X, Y and Z will need to constantly be moving together. To my knowledge though, any 3d shape could actually be cut as 2 1/2D.

I've always thought of it like this. 2d - A (single) step. 2 1/2D a set of stairs. 3D - escalator.

What about swarf? This term is NEVER used in our shop. I've heard it used to describe chips made by a cutter, solid drops, even a 'swarf machine'. And I always feel akward saying it.

[Splint]

Parametric?

[bkukowski]

DRO


also, I was confised with the difference between mill, router, end mill, etc when I started

[strat]

not complete but here is a start

- A -

A-Axis- The axis of circular motion of a machine tool member or slide about the
X-axis. VAlues along the A-axis are degrees of rotation about the X-axis.

Absolute System- A numerical control system in which all positional
dimensions, both input and feedback, are given with reference to a common
datum point.

APT Programming- Automatically Programmed Tools. A universal computer
assisted programing system for multi-axis contouring programming. The original
NC programming system, developed for AeroSpace, first used in building and
manufacturing military equiptment.

Algorithm- A computational method for solving problems. Much like a recipe
in cooking, or a plan of attack in the military. Developing the algorithm in
machining is the pre-planning process that creates the orderly procedure for
machining processes to occur.

Alphanumeric- A system of code that consists of the characters A-Z and
numerials 0-9.

Analog- Pertaining to a system that that uses electrical voltage magnitudes or
ratios to represent physical axis positions.

Analyst- A person skilled in the development and definition of techniques to
solve problems.

Arc Clockwise- G02- An arc generated by coordinted motion between two
axes. Curvature of the arc is clockwise with respect to the part and the cartesian
planes.

Arc Counterclockwise-G03-An arc generated by coordinted motion between
two axes. Curvature of the arc is counter-clockwise with respect to the part and
the cartesian planes.

ASCII-(American Standard Code for Information Exchange)A data transmission
code that has been established as an American Standard by the Americam
Standards Association.

Auxiliary Function-M Codes-A programming function used in CNC
machining that controls functions other than axis motion. Tool changing,
coolant on and off, starting and stopping the spindle, etc.

Axis- A principal direction along which the relative movements of a tool or
workpiece occur. Three linear axes, occuring at 90 degree angles from each other,
named X,Y and Z.

Axis Inhibit- A feature of an NC unit that enables the operator to withhold
command information from a machine tool slide.

Axis Inversion-The reversal of plus and minus values along an axis. Mirror
imaging is used to make a left-handed part from a right-handed toolpath. When
axis inversion is used circular interpolation is also reversed.

- B -

Backlash-A relative movement between interacting mechanical parts as a
result of looseness.

Batch Processing-Technique in which items to be processed must be coded
and collected into groups prior to processing.

B-Axis-The axis of circular motion of a machine tool member or slide about the
Y-Axis.

Binary Code-Code based on binary numbers expressed as either 1 or 0, true or
false, on or off.

BIT-Binary Digit-A binary digit has only two possible states. Eight BITS make
up one BYTE.

BCL- Basic Control Language ...EIA/ANSI 494. A CNC controller language.
This was contributed by Steve Harris For more information on BCL visit
http://www.ncbsa.org Thanks Steve!

Block-A single line of NC code is a block, a block represents sufficient
information to a CNC machine to perform a single line or arc movement.

Block Delete-A function that permits selected blocks of code to be ignored by
the control system, at the operators discretion.

Buffer Storage-A place in which information in a control system or computer
is stored for use at a later time.

Bug-A programmed error or oversight, a glitch.

BYTE-A sequence of eight adjacent binary digits(BITS)


- C -

CAD-(Computer Aided Design)The using of computers to assist and develop
phases of design.

CAM-(Computer Aided Manufacturing)The use of computers to assist in
manufacturing.

Cancel-A command that will discontinue any canned cycles or seguence
commands.

Canned Cycle-A preset sequence of events initiated by a single G coded
command.

Cartesian Coordinates-A three dimensional system whereby the position of
a point can be defined with reference to a set of axes at right angles to each other.

C-Axis-The axis of circular motion of a machine tool member or slide about the
Z-axis. C-axis values are degrees of rotation about the Z-axis.

Chip-A single piece of silicon cut from a slice by scribing or breaking. A chip
can contain one or more circuits.

Circular Interpolation-The process of generating up to 360 degrees of arc
using only one block of information as defined by EIA.

CL Data-Processor output that contains information regarding cutter location.

CNC-Computerized Numerical Control.

Command-A signal or series of signals that initiates one step or a series of steps
in the execution of a program.

Compile-To generate a machine language program from a computer program
written in a high level source code.

Console-The part of a computer system used by the operator for communication
with the computer system.

CPU-Central Processing Unit of a computer. The memory and logic area of a
computer that includes processing and execution of instructions.

CRT-Cathode Ray Tube-A device that displays alphanumeric data to the
machine operator.

Cutter Diameter Compensation-CDC-A system in which the programmed
toolpath may be altered to compensate for cutter diameter differences.

Cutter Offset-The distance from the part surface to the axial center of a
cutter(the radius of the cutter).

Cutter Path-The path defined by the center of the cutter.

Cycle-A sequence of operations that is repeated. The time the repetition requires
is cycle time.

- D -

Data-The representation of information in the form of NC Words, sysmbols,
numbers, letters, characters and/or digits.

Database-A comprehensive collection of information in a specific format
applicable to a user's needs.

Debug-To troubleshoot, detect, locate and remove mistakes from a program.

Decimal Code-A code system in which each allowable position has ten possible
states.

Digit-A single character in any numbering system.

Digital-Relating data in the form of digits.

Display-A visual representation of data.

Downtime-Time during which equipment is inoperable because of faults.

DNC-Direct Numerical Control-A system in which machine coded programs
are introduced into the CNC controller from a remote computer.

Dwell Time-A timed delay of programmed or established duration used in
specific machining operations.

- E -

Edit-To modify the form of data.

EIA Standard Code-A standard code for positioning, linear motion, and
contouring control systems proposed by the U.S. EIA Standard RS-244.

End-Of-Block Character-A character representing the end of a programmed
block of information.

End of Program-A miscellaneous function (M02) that represents the
completion of a programmed cyle.

End Points-The extremities of a span.

Executive Program-A set of programming instructions that allows a CNC
lathe to have the capability to perform lathe functions or a CNC mill to perform
milling functions. A set of instructions designed to output specific functions.

- F -

Feed-A programmed or manually established rate of movement of the cutting
tool into the workpiece for the required machining operation.

Feed Rate-F Word-A multi-character code containing the letter F followed by
digits that determine the machine slide rate of movement.

Feed Rate Override-A variable manual control function that allows the control
system to increase or reduce programmed feedrates.

File-An organized collection of relevent, orderly data.

Firmware-Programs or controlled instructions that are not changeable by the
user and that are often held in ROM,Read Only Memory.

Fixed Block Format-A format where data blocks appear in sequentially arranged
order.

Fixed Cycle- A preset sequence of events initiated by a single G coded command.

Floating Zero-A characteristic of a machine control unit that allows the zero
reference point to be established at any point of travel along an axis.


- G -

Gauge Height-A predetermined Z axis clear plane retraction point along the
Z-axis to which the cuter retreats allowing safe XY axis travel.

GIGO-Anacronym for "Garbage In, Garbage Out", when a programmer is
given garbled inaccurate information (geometry), the BEST that can be expected
is an inaccurate toolpath. ALWAYS, proof every number given to you from
any Engineer, if you don't you will be re-programming 75% of the work!

G Code-Active Preparatory Function-An NC word addressed by the letter G
and followed by a numeric value, G Codes are flags that when executed by the
machine control unit, initiate axis motions, plane changes, feedrate changes, etc.

***Warning: G Codes have different uses and functions from one
Machine Tool Builder to another, use caution when
changing to unfamiliar machines!
G00-Rapid Travel-Axis motion at maximum speed.-Milling-Turning-

G01-Linear Interpolation-Straight linear axis motion at a controlled feedrate.
-Milling-Turning-

G02-Clockwise circular motion using two axes in a single program block.-
Milling-Turning-

G03-Counter-clockwise circular motion using two axes in a single program
block.-Milling-Turning-

G04-A dwell, stoppage of axis motion, for a programmed length of time.
-Milling-Turning-

G17-X,Y plane selection.-Milling-

G18-X,Z plane selection.-Milling-

G19-Y,Z plane selection.-Milling-

G20-G70-Inch units(G20 or G70 depends on the MTB)-Milling-Turning-

G21-G71-Metric units(G21or G71depends on the MTB)-Milling-Turning-

G28-Automatic return to a reference point.-Milling-Turning-

G29-Automatic return from a reference point.-Milling-Turning-

G40-Milling-Cancel Cutter Diameter Compensation

G40-Turning-Cancel Tool Nose Radius Compensation.

G41-Milling-Cutter Diameter Compensation on, cutter left.

G41-Turning-Tool Nose Radius Compensation Left

G42-Milling-Cutter Diameter Compensation on, cutter right.

G42-Turning-Tool Nose Radius Compensation Right

G70-Turning-Canned Finishing Cycle

G71-Turning-Canned Roughing Cycle

G72-Turning-Canned Facing Cycle

G74-Turning-Canned Peck Drilling Cycle

G75-Turning-Canned Grooving Cycle

G76-Turning-Canned Threading Cycle

G80-Cancel Canned Cycle.-Milling-

G81-Canned Drilling Cycle.-Milling-

G82-Canned Cobore Cycle.-Milling-

G83-Canned Deep Hole Drilling Cycle.-Milling-

G90-Absolute Positioning.-Milling-

G91-Incremental Positioning.-Milling-

G92-Repositioning or re-setting the origin point.-Milling-

G98-Milling-The initial machine reference positioning system.(Machine
Reference Zero)

G98-Turning-Linear Feedrate Per Time.

G99-Milling-Cancel G92 position set.(PaArt Reference Zero)

G99-Turning-Feedrate Per Revolution


H -

Hard Copy-A readable output of data on paper.

Hardware-The components that make up a computer or control system.

Hard-Wired-Having logic circuits interconnected on a backplane to give a
fixed pattern of events.



- I -

Incremental Dimensioning-A method of expressing a dimension with respect
to the preceding point. NOT a good idea, incremental dimensioning allows
users to fall into a trap. If a single error in data is entered incorrectly at the
beginning of a project, ALL points determined afterwards will have that
amount of error built into them.

Inhibit-To prevent an action or event.

Input-Transfer of external data into the control system.

Interpolation-A function of a control whereby data points are generated
between given coordinate positions.

ISO-International Organization of Standardization.



- J -

Jig- A fixturing device used most often for drilling operations.

Jog-A control function that momentarily operates a drive into the machine.



- K -





- L -

Leading Zeros-Redundant zeros to the left of a number.

Letter Address-Often called NC Words, such as X,Y,Z,F,G,M.

Linear Interpolation-A control function whereby data points are generated
between given coordinate positions to allow simultaneous movement one, two
or more axes of motion in a linear path.

Loop-Repetitive operations can be programmed in a continuous mode until the
desired functions have been completed.

- M -

Machine Code-Code obeyed by a computer that needs no further translation.

Machining Center-Machine tools, normally Numerically Controlled, capable
of automatically repeating many operations such as drilling, reaming, tapping,
milling, and boring multiple faces on a workpiece.

Machine Tool-A power driven machine used to form or shape metal and other
materials.

Macro-A group of instructions that can be stored and recalled to solve a
recurring problem.

Magnetic Tape-A tape made of plastic or mylar that is covered with magnetic
particles. It stores information by selective polarization of portions of the surface.

Manual Data Input-MDI-A mode of control that allows the operator to input
data into the control system, the data input is identical to the data that can be
input by other means such as tape or DNC.

Manual Part Programming-The preparation of a manuscript in machione
control language and format to define a sequence of commands for processing
by a CNC machine.

Manuscript-A written or printed copy, in symbolic form, containing the same
data as that punched on cards or retained in a memory unit.

Memory-An organized collection of storage elements into which a unit of
information consisting of a binary digit can be stored and from which can later
be retreived.

Mirror Image-The reversal of plus and minus values along an axis. Mirror
imaging is used to make a left-handed part from a right-handed toolpath. When
axis inversion is used circular interpolation is also reversed. Use of (INV,X1Y0)
is a Type II language command.

Modal-Pertaining to information that is retained by the system until new
information is obtained that replaces it.

Module-An interchangeable plug-in item containing components.



- N -

N/C-Numerical Control-The technique of controlling a machine or process by
using command instructions in coded numerical format.

Null-Pertaining to a zero output from a device.

- O -

Offset-A displacement in the axial direction of the tool equal to the difference
between the actual tool length and the programmed tool length.

Optional Stop-A miscellaneous function similar to Program Stop(M01) except
that the control ignores the command unless the operator has previously
pushed a button to validate the command.

Output-Data transferred from an internal storage unit to storage or an
output device.

Overshoot-The amount by which axis motion exceeds the target value.

- P -

Parabola-A plane curve generated by a point moving so that it's distance
from a fixed second point is equal to it's distance from a fixed line.

Parabolic Interpolation-Control of a cutter path by interpolation between
three fixed points, with the assumption that the intermediate points are on
a parabola.




- Q -

(empty)


- R -

(empty)


- S -




- T -

(empty)


- U -

(empty)


- V -

(empty)


- W -

(empty)


- X -

(empty)


- Y -

(empty)


- Z -

(empty)


- # -

(empty)

[Docter Don]

Anyone going to do more on this? There are still things I need to learn, after repairing industrial electronics / electrical for the last 15 years.

Right now I'm looking for the def for "Gantry" -- same as moving table on a mill?

Thanks!

Don

[widgitmaster]

WIDGIT:
Widgit is a general-purpose term, or placeholder name, for any unspecified device, including those that have not yet been invented. It is commonly used in textbook and other examples where the identity of the product or function is irrelevant and could be distracting: students may be asked to design a business plan for the XYZ Widgit Company. Compare Acme.

Just thought I'd add my 2 cents

[Docter Don]

Not to be too picky, but I always saw it spelled "widget" (I just started using the Yahoo! Widget engine, lots of cool ways to junk up your desktop and gum up your computer's operations!).

Please don't take this as offensive. The English language is one of my favorite play-toys, and I feel very sorry for anyone who needs to learn it as an adult -- it is so very hard for little children who don't know anything else -- I am having a blast learning Spanish, with its (not it's) relatively small list of irregular verbs.

Don

[widgitmaster]

Yes, you're correct, i just fudged it to match my handle!

[Docter Don]

What kinds of widgits do you master / make?

Don

[widgitmaster]

Originally Posted by Docter Don What kinds of widgits do you master / make? Don

My NEW Mini CNC Router Design!