COORDINATE MEASURING MACHINE

Views:
 
Category: Entertainment
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

COORDINATE MEASURING MACHINE:

COORDINATE MEASURING MACHINE 1

Need of CMM:

Over the years people have developed fast ways of manufacturing a part but may spend hours trying to inspect the part to make sure that all dimensions are correct. This show the need for the Coordinate Measuring Machines. A machine that can be automated and do precise measurements in a three dimensional space. Need of CMM 2

FIRST CMM MACHINE:

The first machines had the basic structures of the modern CMMS. They were designed to display a two dimensional space (x and y ) with a given reference origin. One of the very first CMMs was develop in the early 1960’s by a company in Scotland called Ferranti. FIRST CMM MACHINE 3

CMM WITH THREE AXIS:

CMM WITH THREE AXIS 4

COORDINATE MEASURING MACHINE:

A coordinate measuring machine, or CMM, is an optical device used for measuring physical and geometrical characteristics of a certain object. COORDINATE MEASURING MACHINE 5

CMM:

To accomplish measurements in 3D, a basic CMM is composed of the following components: Probe head and probe to contact the work part surface. Mechanical structure that provides motion of the probe in three Cartesian axes and displacement transducers to measure the coordinate values of each axis. In addition, many CMM have the following components: Drive system and control unit to move each of the three axes Digital computer system with application software. CMM 6

SPECIFICATION:

X,Y,Z measurement length Resolution Work piece weight Control Operation Mounting Options Probe/Sensor type Application features General applications SPECIFICATION 7

PROBES:

Touch Trigger Probes: Being the least expensive yet capable of measuring just about everything on a machined part, are used in the majority of applications. They usually consist of a probe head, fixed or indexable, the touch probe itself and the style. Mechanical Scanning Probes: They are used to gather a high number of points in bores and surfaces of prismatic parts and for digitizing non-linear unknown surfaces. PROBES 8

PROBES:

The Single Point Laser :It is also used for digitizing. It is an excellent tool to check the profile of delicate surfaces e.g. coated optics and soft parts since it does not physically touch the part. The Line Laser :It is the fastest way to digitize or inspect non-linear surfaces and contours like cell phone housings or car body parts. PROBES 9

CMM CONTROLS:

The methods of operating and controlling a CMM can be classified into four main categories: Manual drive, Manual drive with computer-assisted data processing, Motor drive with computer-assisted data processing, and Direct Computer Control with computer-assisted data processing CMM CONTROLS 10

MANUAL DRIVE:

In manual drive CMM, the human operator physically move the probe along the machine ’ s axes to make contact with the part and record the measurements. The measurements are provided by a digital readout, which the operator can record either manually or with paper print out. Any calculations on the data must be made by the operator. MANUAL DRIVE 11

MANUAL DRIVE:

MANUAL DRIVE 12

MANUAL DRIVE AND CADP:

A CMM with manual drive and computer-assisted data processing provides some data processing and computational capability for performing the calculations required to evaluate a given part feature. The types of data processing and computations range from simple conversions between units to more complicated geometry calculations, such as determining the angle between two planes. MANUAL DRIVE AND CADP 13

MANUAL DRIVE AND CADP:

MANUAL DRIVE AND CADP 14

MOTOR DRIVEN CMM:

A motor-driven CMM with computer-assisted data processing uses electric motors to drive the probe along the machine axes under operator control. A joystick or similar device is used as the means of controlling the motion. Motor-driven CMMs are generally equipped with data processing to accomplish the geometric computations required in feature assessment. MOTOR DRIVEN CMM 15

CMM WITH DCC:

A CMM with direct computer control (DCC) operates like a CNC machine tool. It is motorized and the movements of the coordinate axes are controlled by a dedicated computer under program control. The computer also performs the various data processing and calculation functions. As with a CNC machine tool, the DCC CMM requires part programming. CMM WITH DCC 16

DCC CMM Programming :

There are two principle methods of programming a DCC measuring machine: Manual lead through method. Off-line programming. In the Manual Lead through method, the operator leads the CMM probe through the various motions required in the inspection sequence, indicating the points and surfaces that are to be measured and recording these into the control memory. During regular operation, the CMM controller plays back the program to execute the inspection procedure. Off-line Programming is accomplished in the manner of computer-assisted NC part programming, The program is prepared off-line based on the part drawing and then downloaded to the CMM controller for execution. DCC CMM Programming 17

SOFTWARE:

Measuring software is the most important part of a Coordinate Measuring Machine . Whichever software takes the least number of keystrokes or mouse clicks to measure a feature or a complete part is the better one. CAD is good enough for simple parts. But when it has progressed to a point where it’s close to being seamless, it would require quite a knowledgeable operator. SOFTWARE 18

APPLICATIONS:

Dimensional Profile measurement measurement Angularity or orientationity Depth mapping Shaft measurement Digitizing or imaging APPLICATIONS 19

WHERE TO USE CMM:

WHERE TO USE CMM 20

TYPES OF ITEM CHECKED:

TYPES OF ITEM CHECKED 21

ENVIRONMENT WHERE CMM IS USED:

ENVIRONMENT WHERE CMM IS USED 22

FUTURE:

The future of CMMs leans toward full automation of machines with minimal operator influences. This will decrease inspection time as well as free operator from sitting in front of the machine hours just to make sure that it’s performed the procedure correctly. FUTURE 23

VIDEOS:

http://www.youtube.com/watch?v=aZDL0RB5vuY http://www.youtube.com/watch?v=z2DXyx459Lw http://www.youtube.com/watch?v=gYwfcJJI0NI&feature=related http://www.youtube.com/watch?v=fdITwApB7n4&feature=BF&list=PLD6154210CB4F3D86&index=3 http://du102w.dub102.mail.live.com/default.aspx?wa=wsignin1.0 VIDEOS 24

THE END:

THE END 25