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Showing posts from June, 2010

CAD/CAM Related Career Paths

The following career paths are also pursued by persons interested
the field of CAD/CAM technology:

. Engineering
. Animation
. CAD/CAM software development
. CAD/CAM hardware development
. CAD/CAM software maintenance and troubleshooting
. CAD/CAM consulting services
. CAD/CAM instruction services
. CAD/CAM marketing and sales
. Simulation technology
. Robotics
. Digital art and advertising
. Internet development and consulting
. Cutting tool designer
. Architectural designer
. Rehabilitation technology
. Medical imaging systems
. Digital gaming and amusement systems

What Does a CAD/CAM Operator Do?

What Does a CAD/CAM Operator Do?

CAD operators are in demand in virtually every area of design.
A CAD operator with a backround in architectural design, for example,
would find employment in a firm that is involved in either residential or
commercial construction.
The operator would generate construction drawings on CAD from sketches and
specifications from the architect. All modifications, schedules and 3D
presentation models would also be created in CAD and plotted for the office and
the client.
The CAM operator, works with the production engineer to develop a process
plan or plan to manufacture a part. The operator then utilizes CAM software to
generate a set of instructions to the computer controlled manufacturing
machines. The operator takes care the process plan is adhered to when
generating the instructions. The CAM operator and production engineer
select the machine(s) and cutting tool(s) to be used in production

What Must a CAD/CAM Operator Know?

A CAD/CAM operator should be able to read …

Bench-top cnc machine image

5-axis machining

5 Axis Machining - For incredibly demanding machining of complex designs to execute a very accurate component. From Optical Switch to CT and MRI Scanner components. True 5 axis machining. CNC Machining - 3, 4 Axis machining services for close tolerance applications. While specialising in 5 Axis work, 4 Axis Milling for the truly discriminating needs of aerospace and fibre industries is offered. Precision Machining - Exacting tolerances of .00004” to .004” (one to one hundred microns). Unfortunately machining services for the automotive industry is not offered. Only ultra precision work. Wire EDM - The wire EDM department offers .001” dia wire cut with .0015” corner radii and a positional accuracy of ½ of a micron. (0.00002” or twenty millionths). Machine Shop - Machine shop is for precision machining but small parts only. Work Envelope Size: X:24", Y:14", Z:12" maximum. Micro Machining - Production of miniature components with micron tolerances is well within machining …



Boring always involves the enlarging of an existing hole, which may have been made by a drill or may be the result of a core in a casting. An equally important, and concurrent, purpose of boring may be to make the hole concentric with the axis of rotation of the workpiece and thus correct any eccentricity that may have resulted from the drill's having drifted off the center line. Concentricity is an important attribute of bored holes. When boring is done in a lathe, the work usually is held in a chuck or on a face plate. Holes may be bored straight, tapered, or to irregular contours. Boring is essentially internal turning while feeding the tool parallel to the rotation axis of the workpiece.


Facing is the producing of a flat surface as the result of a tool's being fed across the end of the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be faced, it must be turned end for end after the first end is completed and the facin…

Adjustable cutting factors in Machining

Speed, always refers to the spindle and the workpiece. When it is stated in revolutions per minute(rpm) it tells their rotating speed. But the important figure for a particular turning operation is the surface speed, or the speed at which the workpeece material is moving past the cutting tool. It is simply the product of the rotating speed times the circumference (in feet) of the workpiece before the cut is started. It is expressed in surface feet per minute (sfpm), and it refers only to the workpiece. Every different diameter on a workpiece will have a different cutting speed, even though the rotating speed remains the same.Feed, always refers to the cutting tool, and it is the rate at which the tool advances along its cutting path. On most power-fed lathes, the feed rate is directly related to the spindle speed and is expressed in inches (of tool advance) per revolution ( of the spindle), or ipr. The figure, by the way, is usually much less than an inch and is shown as decimal amoun…

What is Numerical Control ?

Numerical control (NC) is the operation of a machine tool by a series of coded
instructions consisting of numbers, letters of the alphabet, and symbols that the machine control
unit (MCU) can understand. These instructions are changed into electrical pulses of current that
the machine's motors and controls follow to carry out manufacturing operations on a workpiece.
The numbers, letters, and symbols are coded instructions that refer to specific distances,
positions, functions, or motions, that the machine tool can understand as it machines the


A form of NC was used in the early days of the industrial revolution, as early as 1725,
when knitting machines in England used punched cards to form various patterns in cloth. Even
earlier than this, rotating drums with prepositioned pins were used to control the chimes in
European cathedrals and some American churches. In 1863, the first player piano was patented;
it used punched paper rolls, through which air passed to automatica…

Machine controller in CNC

MACHINE CONTROLLER converts the G CODES in to action , The controller interprets the signal from the Control Computer and instructs the machine to move using STEPPER MOTORS and/or SERVO MOTORS . MACHINE CONTROLLERS are build up off Micr-controllers, OP-AMPS, I/O PORTS etc.

CNC Programing Sample Problems

1.Write a part program to cut as shown in FIG-1

Ans :


N011 G01 X1 Y2; MOVE TO (1.2)

N012 G01 X2 Y2; MOVE TO (2.2)


N014 G01 X1; MOVE TO (3.2)


N016 G01 X1 Y2; MOVE TO (3,3) ABSOLUTE

N017 G92 X0 Y0 Z0; RESET TO ZERO

refer G CODES

M CODES used in CNC

# M00 - program stop
# M01 - optional stop using stop button
# M02 - end of program
# M03 - spindle on CW
# M04 - spindle on CCW
# M05 - spindle off
# M06 - tool change
# M07 - flood with coolant
# M08 - mist with coolant
# M08 - turn on accessory #1 (120VAC outlet) (Prolight Mill)
# M09 - coolant off
# M09 - turn off accessory #1 (120VAC outlet) (Prolight Mill)
# M10 - turn on accessory #2 (120VAC outlet) (Prolight Mill)
# M11 - turn off accessory #2 (120VAC outlet) (Prolight Mill) or tool change
# M17 - subroutine end
# M20 - tailstock back (EMCO Lathe)
# M20 - Chain to next program (Prolight Mill)
# M21 - tailstock forward (EMCO Lathe)
# M22 - Write current position to data file (Prolight Mill)
# M25 - open chuck (EMCO Lathe)
# M25 - set output #1 off (Prolight Mill)
# M26 - close chuck (EMCO Lathe)
# M26 - set output #1 on (Prolight Mill)
# M30 - end of tape (rewind)
# M35 - set output #2 off (Prolight Mill)
# M36 - set output #2 on (Prolight Mill)
# M38 - put stepper motors on low power standby (Prolight …

G-CODES used in cnc

1. G00 - Rapid move (not cutting)
2. G01 - Linear move
3. G02 - Clockwise circular motion
4. G03 - Counterclockwise circular motion
5. G04 - Dwell
6. G05 - Pause (for operator intervention)
7. G08 - Acceleration
8. G09 - Deceleration
9. G17 - x-y plane for circular interpolation
10. G18 - z-x plane for circular interpolation
11. G19 - y-z plane for circular interpolation
12. G20 - turning cycle or inch data specification
13. G21 - thread cutting cycle or metric data specification
14. G24 - face turning cycle
15. G25 - wait for input #1 to go low (Prolight Mill)
16. G26 - wait for input #1 to go high (Prolight Mill)
17. G28 - return to reference point
18. G29 - return from reference point
19. G31 - Stop on input (INROB1 is high) (Prolight Mill)
20. G33-35 - thread cutting functions (Emco Lathe)
21. G35 - wait for input #2 to go low (Prolight Mill)
22. G36 - wait for input #2 to go high (Prolight Mill)
23. G40 - cutter compensation cancel
24. G41 - cutter …

Computer Numerical Control

A computer controller is used to drive an NC machine directly. (more on Numerical Control ),

The need of CNC program is be able to direct the position of the cutting tool. As the tool moves we will cut metal (or perform other processes). I we plan to indicate positions we will need to coordinate systems. The coordinates are almost exclusively cartesian and the origin is on the workpiece.

Cartesian Coordinate System

Primitive people used their 10 fingers and 10 toes to count numbers and from this
evolved our present decimal, or Arabic system where "base ten," or the power of 10, is used to
signify a numerical value. Computers and MCUs, in contrast, use the binary or base 2 system to
recognize numerical values. Knowledge of the binary system is not essential for the programmer or operator since both the computer and the MCU can recognize standard decimal system and
convert it to binary data.

Almost everything that can be produced on a conventional machine tool can be produce…