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brown & sharpe Global 9128 User Manual

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© 2000 Brown&Sharpe Manufacturing Company

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Summary of Contents for brown & sharpe Global 9128

  • Page 1 © 2000 Brown&Sharpe Manufacturing Company...

  • Page 3: Table Of Contents

    Contents GENERAL INFORMATION..............1-1 ................1-3 ORDS BOUT ANUAL ....................1-4 DDITIONAL INFORMATION ................1-4 EEDBACK ABOUT THIS OCUMENT ....................1-4 ONTROLLER EFERENCES MACHINE SAFETY....................1-5 General Saftey....................1-5 Electrical Safety....................1-6 Pneumatic Safety .................... 1-6 & S ....1-7 ROWN HARPE LOBAL OORDINATE EASURING ACHINE ..................
  • Page 4 Contents MAJOR COMPONENTS ................5-1 ..................5-3 RANITE AND EDESTALS ......................5-6 RIDGE Pneumatic System ..................5-10 Pneumatic System Air Pressure Adjustment ..........5-11 Counterbalance Cylinder Air Pressure Adjustment........5-12 SYSTEM OPTIONS ..................6-1 ................6-3 EMPERATURE OMPENSATION ............... 6-3 ANUAL EMPERATURE OMPENSATION ..............
  • Page 5 Contents ) ......... 8-5 YSTEM ROUBLESHOOTING OMPUTER AND ERIPHERALS The computer won’t turn on ................8-5 No Power to Monitor ..................8-5 Printer does not work ..................8-5 ................8-7 REQUENTLY SKED UESTIONS SYSTEM MAINTENANCE................9-1 ................... 9-3 AINTENANCE NFORMATION Safety- ......................

  • Page 7: General Information

    SECTION 1 General Information A Few Words About this Manual Additional Information Feedback about this document Machine Safety General Safety Electrical Safety Pneumatic Safety The Brown & Sharpe Global Coordinate Measuring System System Specifications Global 9xx8 Specifications Global 12xx10 Specifications 1-10 Global 9xx8/12xx10 Capacity View Global General Information Global User Manuall...

  • Page 9: A Few Words About This Manual

    A few words about this manual This manual has been developed to provide personnel with information required to operate the Brown & Sharpe CMM in a safe and efficient manner. All personnel associated with the machine’s operation, including but not limited to Maintenance and Machine Operators, should read this document in its entirety and understand its contents.

  • Page 10: Additional Information

    Additional information If you would like to learn more about Brown & Sharpe, or for information about upcoming training classes, please visit our web site at this address: http://www.brownandsharpe.com This manual is also available on the Internet at the following address.

  • Page 11: General Saftey

    Machine Safety Operating any system in a safe manner is a full time job. Always concentrate on the job you are working on and stay focused. Distractions can prove to be dangerous to you, the people working around you or the machine. Read and understand the safety list below before proceeding any further in this manual.
  • Page 12 Electrical Safety √ Never troubleshoot any electrical problems unless you are experienced in diagnosing electrical faults. √ Keep the controller cabinet closed to prevent accidental contact with potentially energized electrical components. √ Always disconnect and lockout the power cabinet before attempting ANY repairs on the system.
  • Page 13 The Brown & Sharpe Global Coordinate Measuring Machine The Brown & Sharpe Global Coordinate Measuring Machine (CMM) you have purchased is the most technically advanced and functionally accurate CMM on the market today. The unmatched accuracy and increased speed capability will provide an excellent return on your investment.

  • Page 14: Ystem Pecifications

    System Specifications Global General Information Global User Manual...
  • Page 15 Floor Plan - Global 12XX10 Right Side View Global General Information Global User Manuall...
  • Page 16 Floor Plan - Global 9XX8 Front View 1-10 Global General Information Global User Manual...

  • Page 17: System Set-Up

    SECTION 2 System Set-Up Operating Tips Start-Up Checklist Starting the GC-1 Controller Starting the GC-2 Controller Mounting Parts 2-10 Probe Installation System Set-Up Global User Manual...

  • Page 19: Operating Tips

    Operating Tips If you are unsure about the correct way to perform a job, ask for instructions before proceeding. During the CMM’s operation, do not allow the probe or Z ram to strike the workpiece or other obstacle. During the CMM’s operation, do not allow the bridge, X-Z carriage, or Z ram to impact the end stops.
  • Page 20 Machine and work station are in position and level. The machine must be allowed to thermally stabilize prior to calibration. Stabilization times will vary by size and thick- ness of granite. Shipping brackets and preload bearing clamps have been removed ·...
  • Page 21 · Verify there are no obstacles which will obstruct ma- chine travel. · With the power strip turned “Off”, connect the power strip to the facility supplied electrical power source. Stop and Start Contingencies: · If power loss occurs, the procedure for restarting is the same as described in the Electrical Power Up procedure.
  • Page 22 If the machine is left unattended- press the “E-Stop” button. Power “E -Stop ” Switch B u tto n Note- The Emergency Stop or “E-Stop” button will stop all machine functions. This is consid- ered a “hard stop” and is fatal to the program’s execution.

  • Page 23: Starting The Gc-2 Controller

    Starting the GC-2 Controller 1. Check machine visually to ensure that all guards and covers are in place 2. Verify that inlet supply pressure is between 80 and 120 psi. 3. Turn on the air supply to the CMM and verify that the pressure gauge reads 58 psi.

  • Page 24: Starting The Gc-1 Controller

    11. Press ‘Machine Start” on the jog box to initiate the homing sequence. Starting the GC1 Controller 1. Check machine visually to ensure that all guards and covers are in place 2. Verify that inlet supply pressure is at least 80 and 120 psi.

  • Page 25: Mounting Parts

    Mounting Parts The following steps for mounting a workpiece to the work- table are necessary to ensure an accessible and stable workpiece during the measuring operation. The more accessible and stable the workpiece, the more accurate the results. · Remove all obstructions from the worktable’s surface. ·...
  • Page 26 Caution: Do not overtorque the clamp bolts. Overtorquing may cause the worktable insert to come loose from the worktable. The maximum allowable torque is 15 ft. lbs. · If using a clamp or bracket locate the workpiece as close as possible to the operator using the closest insert.

  • Page 27: Probe Installation

    Probe Installation The Global CMM is assembled with a standard Renishaw PH10MQ Probe Head (with Autojoint), and equipped with a single standard Probe (refer to the following table). A Renishaw Hand Control Unit (HCU1) controls the movement of the PH10MQ probe head in the A and B axis of rotation. The probe (and if required, the PAA1 Adapter) is attached to the probe head, and the probe head is installed in the Z ram (quill).
  • Page 28 Renishaw PAA1 Renishaw TP20 Renishaw SP600M Renishaw TP200 Removal of the Probe TP20/200 and adapter · Using the hand key, rotate the locking/unlocking screw clockwise a 1/6 of a turn (screw groove goes to horizontal) releasing the adapter from the probe head. TP 20/200 to adapter ·...
  • Page 29 L o c k ing / u n lo c kin g S c re w Hand Key Locking/Unlocking Screw Counter-Clockwise Removal Releasing the Probe Screw Groove System Set-Up 2-13 Global User Manual...
  • Page 30 Installation of the Probe TP20/200 and adapter · Using the hand key, rotate the locking/unlocking screw clockwise a 1/6 of a turn (screw groove goes to horizontal) releasing the adapter from the probe head. TP 20/200 to adapter · Use C clamp tools from Renishaw Stylus Change ·...
  • Page 31 Alignment Dots System Set-Up 2-15 Global User Manual...
  • Page 32 Removal of the Probe Head Caution: Electrical and pneumatic power to the CMM must be turned off prior to removing the probe head. 1. Turn off electrical and pneumatic power to the CMM. 2. If installed, remove the probe from the probe head. 3.
  • Page 33 Installation of the Probe Head Caution: Ensure electrical and pneumatic power to the CMM is turned off prior to installing the probe head. 1. Connect the electrical cables between the probe head and the Z ram (quill). 2. Insert the probe head into the Z ram (quill) making sure the alignment dot is facing forward.

  • Page 35: Electrical System

    SECTION 3 E l e c t r i c a l System System Power-Up System Schematics System Overview System Requirements Global Electrical System Global User Manual...

  • Page 37: System Power Up

    System Power Up A detailed description of system power up and controllers is located in the Controller Section of this manual. System Schematics System schematics are provided in the Service / Maintenance manual. System Overview The Global CMM will require a dedicated protected circuit to operate correctly.

  • Page 39: Pneumatic System

    SECTION 4 Pneumatic System System Power-Up System Schematics System Overview System Requirements Global Pneumatic System Global User Manual...

  • Page 41: System Requirements

    System Requirements Requirement: Class 4 acc. to ISO 8573, Part 1 Supply Air- -Pressure 80-120 psi 5ft 3 /min. -Flow Rate (minimum) -Quality: < 0.006oz/ft. 3 Water present < 0.0005oz/ft. 3 Oil present Particle size < 15 micron < 0.0008oz/ft. 3 Concentration Supply Line, Flexible 1/4”(ID), rated at 250 psi...
  • Page 42 will only happen when temperatures begin to cool substantially around the machine. If the air temperature surrounding the machine is held relatively constant, condensation is not typically a problem. This air prep system described above will provide the CMM with “instrument quality air” assuming facility supplied air is reasonably clean and dry.

  • Page 43: The Bridge

    If the compressed air system at the facility is reasonably effi- cient, filter life should reach a maximum of 1 year. Even with the most compressed air system it is recommended to replace both filter elements at least once per year. Poor quality compressed air will substantially reduce filter life.
  • Page 44 Air Bearings The system incorporates twenty-two (22) air bearings that are located on the drive leg (Y-axis) and the X-Z carriage (X- and Z- axis); seven (7) of the air bearings are pre-loaded. All are adjust- able and free to pivot. System air is supplied to the air bearings and forced through an orifice that uniformly distributes the pressurized system air throughout the active surface.
  • Page 45 scenario would include resetting the counterbalance pressure and the related safety switch. C o u n te r -b a l a n c e C y lin d e r Counter-balance Cylinder L o c a te d o n to p o f Z ra il. Located on top of Z rail.
  • Page 46 (PCC) Pressure – Counterbalance Cylinder (PAP) Pressure – Machine Air Pressure Each of these is factory switches is factory set to open (turn machine OFF) at pressures 5 psi below normal operating pres- sure. If supply air were reduced to 53 psi, 5 psi below normal operating pressure of 58 psi, the PAP switch would send a signal to the controller to shut the machine down.

  • Page 47: System Power-Up

    System Power-Up · Open all facility-supplied air shut off valves to the system’s air filter/regulator assembly. · Verify that the system air pressure gage, located on the air filter/regulator assembly (refer to the following figure) indi- cates 58 psi. Note- Perform the daily maintenance and inspections before you apply supply air to the filter/regulator assembly.

  • Page 49: Major Components

    SECTION 5 Major Components Granite & Pedestals The Bridge Pneumatic System 5-10 Pneumatic System Air Pressure Adjustment 5-12 Counterbalance Cylinder Air Pressure Adjustment Major Components Global User Manual...

  • Page 51: Granite And Pedestals

    Major Component Overview The major mechanical components that comprise a Global CMM are a granite worktable that rests on a set of pedestals, an aluminum bridge that rides atop the granite along the y-axis, and a X-Z carriage that rides upon the bridge along the x-axis and supports the Z Ram (z-axis).
  • Page 52 Pedestal Placement A n ti-T ip P e d e s ta ls S u p p o rt P e d e s ta ls · The underside of the granite is marked to ensure proper placement of the support pedestals ·...
  • Page 53 The granite worktable uses threaded metal inserts, which secure the bolts and clamps that hold down the workpiece during measurement. These inserts are placed in staggered rows and spaced approximately 8.5 and 12 inches apart. Caution: Do not overtorque the clamp bolts. Overtorquing may cause the worktable insert to come loose from the worktable.

  • Page 54: The Bridge

    The Bridge The bridge is a rigid aluminum alloy assembly comprised of an X rail supported by two (2) legs; a right leg (drive leg) and a left leg. The light weight, aluminum alloy construction provides greater dampening capability and rapidly achieves thermal equilibrium, and thus provides a very short settling time for the CMM.
  • Page 55 X-Z Carriage The X-Z Carriage is a machined aluminum alloy casting that rides along the bridge’s X rail and supports the tower and Z Ram. The carriage is equipped with fifteen (15) air bearings. Six (6) X and and nine (9) Z bearings. Of the two upper back air bearings, the rear air bearing is preloaded and will “lock”...
  • Page 56 Z Ram and Probe Head The Z Ram is mounted vertically within the X-Z carriage and tower. The Z-ram is moved along the z-axis by a drive belt attached to the motor through a series of pulleys and a pulley belt.
  • Page 57 Scales The scales are made of steel or glass and designed to thermally expand with the CMM during expected normal temperature changes. Machines equipped with temperature compensation have scales attached at both ends. They are supported within a channel that is fastened to the machine. The CMM has three (3) separate scales one for each axis of travel (x, y and z) and each with their own separate scanning head (sends a signal to the controller indicating a position along the scale).
  • Page 58 The x-axis scale is mounted on the under side of the X rail along the travel of the X-Z carriage and the x-axis scanning head is located between the lower air bearings on the X-Z carriage. Scale Scanning Head Scale Scanning Head Scale &...

  • Page 59: Pneumatic System

    Pneumatic System Air Pressure Adjustment 1. Verify that all pneumatic system components are installed and functioning properly. 2. Turn “ON” the controller/computer and air system. 3. Adjustment of the system air pressure switch must be accomplished first. Observe the system air pressure gage on the Air Filter/Regulator Assembly, if the gage indicates 55 psi proceed to step 6.

  • Page 60: Counterbalance Cylinder Air Pressure Adjustment

    Air Pressure Switches Air Solenoid Safety Lockout Valve Valve Pressure Switches, Air Valve and Lockout 6. Pull the adjustment knob down on the Air Regulator and turn the knob clockwise until system pressure is increased to 58 psi. Push the adjustment knob up to “snap-lock” the knob back in place.
  • Page 61 4. Verify that the pneumatic “system air” pressure has been properly adjusted. 5. Manually move the Z ram along the axis of travel (up and down) and determine if the exerting forces are equal. This can be accomplished by either “feel” or by using the “drift” method where the ram is allowed to float freely.

  • Page 63: System Options

    SECTION 6 System Options Temperature Compensation Manual Temperature Compensation Linear Temperature Compensation A.C.T.I.V. Probes TP20 Probe TP200 Probe TRAX Probe Head SP-600 Probe Probe Compensation And Qualification Measuring With An Electronic Probe 6-10 Touch Trigger Probe Repeatability 6-13 Planning the Measurement System Options Global User Manual...

  • Page 65: Temperature Compensation

    System Options Temperature Compensation There are three types of temperature compensation systems available. Manual, Linear and A.C.T.I.V. Each one is described below. Any change of temperature in the room where the CMM is located, distorts the geometry of both the machine structure and the work piece.
  • Page 66 for relatively stable work environments. CMMs used in work areas that will likely be subject to substantial temperature gradients would be best served by the A.C.T.I.V. system, which is described on the next page. A.C.T.I.V. Adaptive Compensation of Temperature Induced Variations (A.C.T.I.V.) is a structural temperature compensation system that ensures accurate machine operation in harsh environments.

  • Page 67: Probes

    Probes CMMs gather data by touching the workpiece with a probe attached to the machine’s measuring axis. There are many different probes available for your CMM. The standard probe which was supplied with your CMM will vary depending on the configuration of your particular machine.

  • Page 68: Tp200 Probe

    TP200 Probe High repeatability and 3D form measurement is achieved by using a novel type strain gauge structure to detect small displace- ments of the stylus tip. The strain gauge output is processed and converted into a Renishaw 2 wire system format using an ASIC electronic chip and hybrid micorcircuit technology.

  • Page 69: Probe Compensation And Qualification

    The SP600 Probe is an analog unit which is ideally suited for fine scanning of small intricate objects. The SP600 would be typically be used to vehicle bodu sheet metal and other similar types of objects. The SP600 Probes are also used for profile scanning and measurement on Coordinate Measuring Machines.
  • Page 70 The approach vector determines: · The direction of probe radius compensation during measurement calculations. · A plane’s vector direction · Which bonus tolerance calculation to use when true position tolerancing features. All probes must be qualified before accurate measurements can be made.

  • Page 71: Measuring With An Electronic Probe

    · Clean the stylus with alcohol · Clean reference sphere · Verify stylus is screwed in completely Verify reference sphere is securely bolted to granite Measuring with an Electronic Probe Measurement points are recorded when the stylus is deflected enough to either break mechanical contacts or generate enough force to trigger pressure sensitive circuitry.

  • Page 72: Touch Trigger Probe Repeatability

    Planar and Spherical Probing Touch Trigger Probe Repeatability The touch trigger probe is designed to give optimum results when the probe hits are taken perpendicular to the probe body (perpendicular to the axis of the stylus). Wherever possible make hits perpendicular to the probe body. Probe hits taken parallel to the probe body (along the axis of stylus) give results that are not as repeatable as those taken perpendicular to the axis.
  • Page 73 System Options 6-11 Global User Manual...
  • Page 74 Another possible cause of error is shanking, when the probe contacts the part with the shank of the stylus and not the tip. The measuring system will assume the hit was taken with the tip and large errors will occur. Increasing the diameter stylus ball increases the ball/stem clearance and lessens the likelihood of shanking.

  • Page 75: Planning The Measurement

    Planning the Measurement The first step to approaching a measurement is to review the print or drawing and identify all dimensions which must be verified. Highlighting all dimensions which need to be verified, is an excellent method for ensuring that all relevant dimensions are indeed verified.

  • Page 77: Controls

    SECTION 7 Controls Controller Information GC-2 Controller GC-1 Controller Homing Sequence 7-12 Jog Box Global Controls Global User Manual...

  • Page 79: Controller Information

    Controls Controller Information There are two available controllers which can be used with the Global CMM. The GC-2 and GC-1 controllers. The GC- 2 controller is a stand alone unit used predominantly with larger machines and machines that incorporate the use of Temperature Compensation packages.
  • Page 80 The GC- 2 control system consists of a cabinet with the follow- ing components. A rack which mounts the logic power supply, drive and expansion cards The power supply transformer, relays, fuses, motor power supply and additional components. The cabinet is ventilated via a rack ventilator and incorporates two filtered grates, one on the front and one on the back of the unit.
  • Page 81 Starting the GC-2 Controller 1. Check machine visually to ensure that all guards and covers are in place 2. Verify that inlet supply pressure is at least 80 psi 3. Turn on the air supply to the CMM and verify that the pressure gauge reads 58 psi.

  • Page 82: Controller

    GC-1 Controller The GC-1 control system consists of the GC-1 control, the measuring machine, the computer with its peripheral units, the JogBox and the Probe Control Units. The GC-1 control consists of a metal box assembled on the rear of the computer table. It contains: An inner control box, including the circuits for coordi- nating, handling and driving the three axes of the measuring machine, and interfacing the measuring...
  • Page 83 GC-1 Global Controller and Workstation GC-1 Global Controls Global User Manual...
  • Page 84 Starting the GC-1 Controller 1. Check machine visually to ensure that all guards and covers are in place 2. Verify that inlet supply pressure is at least 80 psi. 3. Turn on the air supply to the CMM and verify that the pressure gauge reads 58 psi.

  • Page 85: Homing Sequence

    8. Power up the computer and log on if necessary. 9. Start the measuring software, if it had not started auto- matically. 10. When prompted, check that all emergency stop buttons are unlatched, then press the MACH. START button on the jog box.
  • Page 86 the table. Refer to Mounting Parts in Section 1 of this manual for additional information. · Additional information about peripheral equipment such as computers and printers can be found in the documen- tation provided with that equipment. NOTE: If the CMM is to be stopped for more than a few hours, it is recommended that the air supply be shut off.
  • Page 87 CAUTION: Always move the probe with extreme caution since any collision with the workpiece or other obstacle could damage the probe. To pick up a point manually • Activate the PROBE ENABLE function (if the LED associated to this button is OFF, press the button to switch it ON) •...

  • Page 88: Jog Box

    Jog Box NOTE: When a button is illuminated, that button’s function is active. When the button’s light is extinguished, that button’s function is inactive. The Jog Box contains the controls for operating the machine. The functions of these buttons are detailed below.. JOG MODE This button is used to select one of three types of movement: ·...
  • Page 89 · CONTINOUS In this mode, the machines direction and velocity is dependant on the direction and amount of deflection of the joystick. SLOW Works in both STEP and CONTINOUS mode. This button enables either slow machine movement (LED illuminated) or fast machine movement (LED extinguished.
  • Page 90 E-STOP This is a latching pushbutton that causes an Emergency-Stop condition when depressed. The E-stop button is connected so that it interrupts the supply to the motor drive circuits by de- energizing a control relay. Joystick control is unavailable in this condition.To re-enable the system, the “E-STOP”...
  • Page 91 F1 (Function Key) This button is not used at this time. X, Y, Z BUTTONS These buttons constrain the movement of the machine to the selected axes when the joystick is deflected. Axes with illumi- nated LED’s are active. When SHIFT is active, the upper register X, Y and Z axes cannot be activated but the lower register A, B and W axes can be activated, if available.
  • Page 92 SPEED (Feedrate Override Control) Allows the machine to run at a fraction of its measuring velocity. Pressing the UP arrow allows the machine to move faster. Conversely, pressing the DOWN arrow, makes the machine move slower. The 10 zone LED display above the ENABLE button displays the percentage, in 10 percent increments, of the machine’s programmed measuring speed.
  • Page 93 SECTION 8 System Troubleshooting & Questions System Troubleshooting (Machine) Machine won’t turn On Machine won’t repeat measurement Inaccurate Measurements Probe does not take hits System Troubleshooting (Computer & Peripherals) The computer won’t turn on No Power to Monitor Printer does not work Frequently Asked Questions System Troubleshooting and Questions Global User Manual...

  • Page 95: System Troubleshooting And Questions

    System Troubleshooting and Questions System Troubleshooting (Machine) Machine won’t turn on · Is the air pressure set to 58 psi? · Is power correctly connected to the system? The GC-2 system requires a duplex outlet. One for the GC-2 and the the other for the workstation power strip. Con nect the controller and workstation accordingly.

  • Page 96: Inaccurate Measurements

    Inaccurate Measurements · Is the part dirty or oily? · Is the surface finish on the part poor? Using a larger diameter ball will reduce the effect of surface finish of the part being inspected. · Was the homing/initialization procedure followed correctly? ·...

  • Page 97: System Troubleshooting (Computer And Peripherals)

    System Troubleshooting (Computer and Peripherals) The computer won’t turn on Are all cables connected properly? Is the voltage setting on the back panel of your computer correct for your location? No Power to Monitor Is the power cord plugged in? Is the power “ON”...
  • Page 98 on the rear panel of the system does not work properly. Is the attached device turned on? Is the cable properly installed between the device and the port? Pressing the <Caps Lock>, <Num Lock> or <Scroll Lock> keys does not light the corresponding light on the keyboard. Is the keyboard cable installed properly? The cursor appears on the monitor, but nothing appears when you press the keyboard keys.

  • Page 99: Frequently Asked Questions

    Frequently Asked Questions Is this manual available on the Internet? All Global service documentation will be online including this document the Site Preparation Manual and the Service/Maintenance Manual. They are located at: http://manuals.brownandsharpe.com Where can I obtain additional information about Brown and Sharpe or upcoming training classes? http://www.brownandsharpe.com Who do I contact to comment about the manuals or to suggest a...
  • Page 100 Are lifting sling assemblies provided by Brown & Sharpe? Are lifting pins? No. If a CMM is to be offloaded, or relocated, using a lifting sling assembly, it is the customer’s responsibility to provide the riggers and the sling assembly. Lifting pins will be provided only with European deliveries.

  • Page 101: System Maintenance

    SECTION 9 System Maintenance Maintenance Inforamtion Safety Maintenance Tips Scheduled Maintenance Intervals Scheduled Maintenance Checklist DailyMaintenance System Maintenance Global User Manual...

  • Page 103: Maintenance Information

    System Maintenance Detailed maintenance information can be found in the Service / Maintenance Manual. Maintenance Information Scheduled maintenance checks must be performed by assigning personnel who are thoroughly familiar with maintenance proce- dures. The more complex inspections must be done by trained maintenance personnel on a regular basis at the minimum intervals shown.

  • Page 104: Safety

    Safety Proper machine maintenance plays a major part in a plant safety program. This maintenance schedule must be followed to ensure safe and continuous operation of the CMM. Follow all recom- mended safety procedures. Always wear safety glasses when performing maintenance on the CMM. Maintenance Tips ·...

  • Page 105: Scheduled Maintenance Checklist

    Note: The scheduled intervals are based on an 8-hour day and a 40-hour week. If the machine is operated greater than the scheduled interval (e.g. two 8-hour shifts a day vs. one), adjust the particular interval as necessary, and continue to perform the preventative maintenance at that scheduled interval (before the first 8-hour shift and before the second 8-hour shift).
  • Page 106 Caution: Ensure the facility supplied air is turned off to the CMM and the system air pressure indicates zero (0) BAR before performing any maintenance to the Air Filter/Regulator Assembly or, the supply air line. Inspect both air filters for contamination. If necessary, drain the filter bowl or replace the filter element.

  • Page 107: Introduction To Cmm

    SECTION 10 Introduction to CMM 10-3 The Coordinate System 10-4 The Machine Coordinate System 10-7 The Part Coordinate System 10-8 An Explanation of Alignment 10-9 An Explanation of Datum 10-11 An Explanation of Translation 10-13 An Explanation of Rotation 10-15 Measured and Constructed Features 10-17 Volumetric Compensation 10-19 Qualifying Probe Tips 10-20 Projections...

  • Page 109: The Coordinate System

    Introduction to CMM While your site is being prepared for the arrival of your new CMM why not take a few minutes and review the information provided below. It is a basic look at Coordinate Metrology. It will serve as an excellent starting point for people new to CMM and an informative review of the basics for the experts.
  • Page 110 The Coordinate System, Continued Ritz Hotel Museum Restaurant Train Station Figure 1 Figure 9 Map Coordinates A coordinate measuring machine (CMM) works in much the same way as your finger when it traces map coordinates; its three axes form the machine’s coordinate system. 10-4 Introduction to CMM Global User Manual...
  • Page 111 The Coordinate System, Continued Instead of a finger, the CMM uses a probe to measure points on a workpiece . Each point on the workpiece is unique to the machine’s coordinate system. The CMM combines the measured points to form a feature that can now be related to all other features.

  • Page 112: The Machine Coordinate System

    The Machine Coordinate System There are two types of coordinate systems in the world of measurement. The first is called the Machine Coordinate Sys- tem. Here, the X, Y, and Z-axes refer to the machine’s motions. When viewed from the front of the machine, the X axis runs from left to right, the Y axis runs from front to back, and the Z axis runs up and down, vertically perpendicular to the other two.

  • Page 113: The Part Coordinate System

    The Part Coordinate System The second coordinate system is called the Part Coordinate System where the three axes relate to the datum’s or features of the workpiece. Before the introduction of computer software to coordinate measurement, parts were physically aligned parallel to the machine’s axes so that the Machine and Part Coordinate Systems were parallel to one another.

  • Page 114: An Explanation Of Alignment

    An Explanation of Alignment With today’s CMM software, the CMM measures the workpiece’s datum’s (from the part print), establishes the Part Coordinate System, and mathematically relates it to the Machine Coordinate System. The process of relating the two coordinate systems is called alignment.

  • Page 115: An Explanation Of Datum

    An Explanation of Datum A datum is a location. We use datum’s as guides to tell others where we are or as directions on how to get to places. On the map shown the Ritz Hotel is a datum. So are streets, the train station, the museum, and the restaurant.
  • Page 116 An Explanation of Datum, Continued In metrology, a datum is a feature on a workpiece such as a hole, surface or slot. We measure a workpiece to determine the distance from one feature to another. Figure 15 Workpiece Datum 10-10 Introduction to CMM Global User Manual...

  • Page 117: An Explanation Of Translation

    An Explanation of Translation Suppose you need to know how far a specific feature of a workpiece is from another feature. Take, for example, the distance to the centers of each of four holes from a central hole. To do this you would first measure the central hole, translate the origin to the center of this hole, and then measure each of the four surrounding holes.
  • Page 118 An Explanation of Translation, Continued In terms of our street map, once you arrive at your hotel and decide to eat at a legendary restaurant on your visit to the city, you need to find it Ritz Hotel (Datum) Museum (Datum) Restaurant (Datum) Train Station (Datum) Figure 6...

  • Page 119: An Explanation Of Rotation

    An Explanation of Rotation Not all datum’s are at right angles to other datum’s. For example, looking at your street map, you see that the Museum is located on a street that’s neither parallel nor at right angles to the streets the Hotel, Restaurant and Train Station is on.
  • Page 120 An Explanation of Rotation, Continued The exact same procedure applies to the workpiece. The distance between the two holes on the workpiece can be measured once the original origin is translated to the smaller hole and the part coordinate system is mathematically rotated 45°. Now both of the holes lie along the new Y-axis and the distance can be calculated automatically.

  • Page 121: Measured And Constructed Features

    Measured and Constructed Features The vast majority of workpieces are made up of simple geomet- ric elements created by machining or forming. These primary elements (planes, edges, cylinders, spheres, cones, etc.) are called features. When a CMM can measure these features directly, by touching the surfaces that make up the feature with a probe, the features are referred to as measured features.
  • Page 122 Measured and Constructed Features, Continued The relationships between one feature and group of features to another feature or group of features are critical to manufacturing. For example, the intersect point between the cylinders on one side of an engine block and those on the other side determines how well mating parts fit.

  • Page 123: Volumetric Compensation

    Volumetric Compensation Although advanced manufacturing technology makes it possible to tolerance and make workpieces very precisely, imperfections still exist. Small as they may be, the fact that there are tolerances means that there are errors. Coordinate measuring machines are no different from other products in this respect.
  • Page 124 Volumetric Compensation, Continued In the map shown below, the difference between true north and magnetic north (3° W), must be compensated for or a sailor would end up northwest of the intended goal and would run aground before reaching the final destination. A coordinate measuring machine does a similar compensation automatically to remove the variations of the machine from the measurement.

  • Page 125: Qualifying Probe Tips

    Qualifying Probe Tips Probe Compensation CMMs generally gather their data by touching the workpiece with a probe (either a solid probe or an electronic touch trigger probe) attached to the machine’s measuring axis. Although the tip of the probe is very accurate, once the probe is attached to the CMM, the location of the tip to the machine’s coordinate system must be determined prior to measuring.

  • Page 126: Projections

    Projections A projection is the reproduction of a workpiece feature on another feature, such as projecting a circle or line onto a plane, or a point onto a line. Projecting one part feature onto another can be compared with the creation of the traditional “flat” map of the world (Mercator projection).
  • Page 127 Projections, Continued A minimum number of three points is necessary to measure the diameter of a circle and, if those points are not at the same distance from the top of the bore, the measured diameter will be shown to be elliptical. To overcome this misrepresentation, the measurement data is projected onto a plane that is perpendicular to the centerline of the cylinder.

  • Page 128: Effective Probe Techniques

    Effective Probe Techniques By using effective probe techniques when inspecting a workpiece, you can eliminate many common causes of measure- ment error. For example, probe measurements should be taken perpendicular to the workpiece surface whenever possible. Touch trigger probes used on coordinate measuring machines are designed to give optimal results when the probe tip touches the workpiece perpendicular to the probe body.
  • Page 129 Effective Probe Techniques, Continued Probe hits taken parallel to the probe body, that is, along the axis of the stylus, are not as repeatable as those taken perpendicular to the axis. Figure 26 Effective Probe Techniques (a) Probe hits that are neither perpendicular nor parallel to the probe body produce results that are even less repeatable than those taken parallel to the probe body.
  • Page 130 Effective Probe Techniques, Continued Shanking is another cause of measurement error. When the probe contacts the workpiece with the shank of the stylus and not the tip, the measuring system assumes the hit was taken in a normal manner and large errors will occur. Figure 27 Shanking 10-24...
  • Page 131 Effective Probe Techniques, Continued You can reduce the likelihood of shanking by using a larger diameter tip to increase the clearance between the ball/stem and the workpiece surface. Generally, the larger the tip diameter, the deeper the stylus can go before it touches the workpiece feature. This is called the effective working length of the probe.

  • Page 132: Geometric Dimensioning And Tolerancing

    Geometric Dimensioning and Tolerancing Geometric Dimensioning and Tolerancing (GD&T) is a universal language of symbols, much like the international system of road signs that advise drivers how to navigate the roads. GD&T symbols allow a Design Engineer to precisely and logically describe part features in a way they can be accurately manufac- tured and inspected.

  • Page 133: Geometric Characteristic Symbols

    Geometric Dimensioning and Tolerancing, Continued There are seven shapes, called geometric elements, used to define a part and its features. The shapes are point, line, plane, circle, cylinder, cone and sphere. There are also certain geomet- ric characteristics that determine the condition of parts and the relationship of features.
  • Page 134 Cylindricity - All the points of a surface of revolution are equidistant from a common axis. A cylindricity tolerance specifies a tolerance zone bounded by two concentric cylinders within which the surface must lie. Profile - A Tolerancing method of controlling irregular surfaces, lines, arcs, or normal planes.
  • Page 135 Parallelism - The condition of a surface or axis equidistant at all points from a datum plane or axis. Parallelism tolerance speci- fies one of the following: a zone defined by two planes or lines parallel to a datum plane or axis, or a cylindrical tolerance zone whose axis is parallel to a datum axis.
  • Page 136 Circular Runout - Provides control of circular elements of a surface. The tolerance is applied independently at any circular measuring position, as the part is rotated 360 degrees. A circular runout tolerance applied to surfaces constructed around a datum axis controls cumulative variations of circularity and coaxiality. When applied to surfaces constructed at right angles to the datum axis, it controls circular elements of a plane surface.
  • Page 137 Introduction to CMM 10-31 Global User Manual...

  • Page 139: Index

    Index A.C.T.I.V.......... 6-4 Additional Major Components ..5-9 Adjustable Pedestals ......5-3 Adjustments / Alignments ..... 5-10 Air Bearings........4-6 Air Filter/Regulator Assembly ..5-5 Air Prep Package ......4-3 Alignment ........10-8 Angularity ........10-28 GC-2 Control Panel ......7-3 GC-2 Controller .......
  • Page 140 Index Effective Probe Techniques ..10-22 Electrical Overview ......3-3 Electrical Requirements ....8-6 Electrical Safety ......1-6 Electrical System ......3-3 GC-1 Controller ....... 7-6 Feedback .......... 1-4 Flatness ........10-27 Frequently Asked Questions .... 8-7 General Safety ......... 1-5 Geometric Dimensioning and Tolerancing ......
  • Page 141 Index Machine Safety ......1-15 Maintenance Information ....9-4 Maintenance Tips ......9-4 Major Components ......5-1 Manual Temperature Compensation 5-1 manuals.brownandsharpe.com ..1-4 Measured and Constructed Features10-15 Measuring with an Electronic Probe 6-9 Mounting Parts ........ 2-8 Operating Tips ......... 2-1 Parallelism ........
  • Page 142 Index Pulleys & Belts ........ 5-8 Qualifying Probe Tips ....10-19 Removal of the Probe ..2-11, 2-13 Removal of the Probe Head ... 2-15 Rotation ........10-13 Roundness or Circularity ..... 10-27 Scale & Scanning Head, y-axis ..5-9 Scale &...
  • Page 143 Index Temperature Compensation ..... 6-1 The Bridge ....... 4-5, 5-6 The Coordinate System ....10-1 The Machine Coordinate System .. 10-6 The Part Coordinate System ..10-7 Total Runout ........ 10-30 Touch Trigger Probe Repeatability 6-10 TP20 Probe ........6-5 TP200 Probe ........

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