IRP200 Bosch Control. Operation Manual

Transcription

1 IRP200 Bosch Control Operation Manual

2 1 Table of Contents Contents 1 Table of Contents Introduction Instructions for This Manual Safety Instructions General Safety Instructions Intended Use of Machine Safety and Protection Devices Organisational Measures Operator Training Safety and Test Circuits of the Control Mechanism Inspection prior to Starting Work Safety Instructions for Working with Machine Safety Instructions related to Programming Instructions related to Handling Safety Instructions for working on Electrical Parts Safety Instructions related to Daily Maintenance The Machine Technical Data Working Range CNC-Axes Continuous Noise Level Machine Dimensions Machine Weight Power Supply Compressed Air Supply Environmental Machine Assemblies Machine Work Chamber Virtual Pivot Plan View of Machine Mechanical Cabinet Air Service Unit and CNC Control Control Panel Switching ON and Switching OFF the Machine Switching On the Machine... 21

3 Chapter: Table of Contents Switching On the Electricity at the MAIN SWITCH Switching On the Computer Reset the Machine Switching On the Compressed Air Supply Switching On the Slurry (Coolant) Supply Switching Off the Machine Shutting Down the Computer Switching Off the Compressed Air Supply Switching Off the Slurry (Coolant) Supply Switching Off the Electricity at the MAIN SWITCH Using Canned Programs Setting Workpiece Co-ordinate System Manual Control of Machine Axes MDI Mode Basic Manual Modes JOG Mode INC Mode MPG Mode Tool Spindle and Workpiece Spindle Commands TOOL SPINDLE (H) Sections WORK SPINDLE (C) Sections Checking and Setting X&Y Zero Position Checking for Virtual Pivot Errors in the A or B Axes Preparing the Bonnet Fitting the Bonnet Dressing the Bonnet/Cloth Moulding Polyurethane Bonnet Polishing Cloths Trimming the Cloth Measuring the Bonnet Cloth Radius Determining the Bonnet Radius Determining the Effective Bonnet/Cloth Radius Checking and Adjusting Workpiece Run-Out Performing a Non-Linear Correction Running a TPG Generated Toolpath Performing a Pre-Polish Introduction Check List Correct Bonnet/Cloth Fitted

4 Chapter: Table of Contents 1.36 Condition Cloth Set Correct Tool Radius/Cloth Thickness Part Preparation Perform a ZTOP Operation Enter Correct Part Parameters in TPG Setting the Polishing TPG Parameters Non-Linear Corrections Generate CNC file Start CNC Generating Influence Function(s) Corrective Polishing Importing an Influence Function Importing an Error Profile from the Form Talysurf Designing the Required Profile Performing an Optimisation Setting Optimisation Parameters Setting Constraints Interpolating an Optimisation Automatic Post Processing of Optimisation Result Manual Manipulation of Dwell Times Modify Dwell Time (Visually) Modify Dwell Time (Manually) Exporting to the ToolPath Generator (TPG) Designing an Error Profile Setting Crash Detection Sensitivity Axis Over-Travel CNC Memory Loading Files from CNC Memory Loading a File into CNC Memory Deleting a File from CNC Memory Manual Setting of G54 Z OFFSET

5 Chapter: Introduction 2 Introduction Dear Customer, This Operating Manual describes all steps need to take in order to work on the IRP 200 machine. Please take time to read the manual carefully. Pay attention to the instructions for this manual given on this and the next page. This manual is structured to guide the user in a step-by-step fashion, leading to the finished work piece. Always keep this manual in the immediate vicinity of the machine, readily available for consultation. In addition to the Operation manual, the user documentation is comprised of the following: Transport and Installation manual Safety Instructions Software manual Maintenance manual Wishing you a lot of success and good results with the IRP 200. Zeeko LTD 4

6 Chapter: Instructions for This Manual 3 Instructions for This Manual The following signs indicate safety or general instructions throughout the text: Imminent Danger which can cause loss of life, serious injuries or extensive damage. Potentially dangerous situation which may cause loss of life, serious injuries or damage. Potentially dangerous situation which may cause injuries or damage. Application instructions and other useful or important information. 5

7 Chapter: Safety Instructions 4 Safety Instructions 1.1 General Safety Instructions The Zeeko IRP200 was built in accordance with the safety regulations in effect in the UK and in Europe. Safety switches and protection devices are installed and active where necessary. This is why the machine must not be rebuilt or altered in any way. Prohibited! Never change or deactivate safety switches or protection devices in any way. Work on the machine must only be performed with the work chamber closed. The work chamber and the safe guards must not be removed or altered. The machine should be checked for visible damage and defects once during each shift. Any changes (including changes in the operating condition) must be reported immediately to the person or authority in charge! If necessary, the machine must be put out of service and secured (e.g. locking of the MAIN SWITCH )! Do not perform any operations that are not described in this manual! The software and the hardware used by Zeeko are free of any computer viruses. Zeeko is not liable for malfunctions and damages resulting from computer viruses. 1.2 Intended Use of Machine The machine is intended to be used for: Light industrial purpose Laboratory purpose University research Manufacture of optical lenses and moulds Never use the machine for any purpose other than that for which it was designed for! 6

8 Chapter: Safety Instructions Safety Instruction! Only perform operations on workpieces made of materials recommended by Zeeko. Do Not: - Use grinding attachments. - Use non-recommended tooling. - Use unauthorised software. 1.3 Safety and Protection Devices The EMERGENCY STOP button is located on the control panel. By pressing this button all machine functions and processing cycles are immediately interrupted. It is a safety release button unlocked by turning. Completely enclosed and interlocked work chamber. The machine can only be operated with the work chamber closed. The doors of the mechanical and electrical cabinets are interlocked. The machine can only be operated with closed mechanical and electrical cabinets. The mechanical cabinet is key locked. Main disconnect switch. Individual movement of the axes is only possible in Manual mode. Access to Manual mode is key lock protected. In Manual mode the A-axis and Z- axis speed is limited to 2m/min. Programme key lock prevents unintended programme changes. 1.4 Organisational Measures This section covers organisational measure. Before attempting to use the machine, read the following safety instructions carefully! Always keep the complete documentation for the machine in the immediate vicinity of the machine and accessible to all machine users. In addition to the Operation manual please observe general, legal and other binding regulations pertaining to accident prevention and environmental protection. The above may also apply to e.g. the handling of dangerous materials as well as making protective clothing available to the operating personnel and enforcing its wear. 7

9 Chapter: Safety Instructions In some circumstances bacterial growth can occur in the polishing fluid tank and the associated pipe work. Zeeko Ltd. is not aware of what type of polishing fluids, additives or agents are used and can therefore not provide any recommendations on how to prevent bacterial and viral growth. We would therefore recommend contacting polishing fluid suppliers for guidance on polishing fluid management and storage. All personnel authorized to operate and work with the machine must have read the Operation manual prior to working with the machine. It is too late to do so while already operating the machine. This applies particularly to personnel charged with e.g. the installation and maintenance of the machine. Operating personnel should at least be supervised from time to time to ensure that all operations are handled in a safety conscious manner! Operating personnel should not wear long/loose hair, loose clothing or jewellery including rings because of the potential danger of injury due to e.g. getting caught up or pulled in to the machine. All safety instructions and warnings must be followed! All safety instructions and warnings on the machine must be kept in legible condition! The machine must be put out of service when any safety related changes are made on the machine, or a change in the operating behaviour becomes apparent, which can influence the operating safety. Immediately report all malfunctions to the responsible party! Replacement parts must conform to the technical requirement of the manufacturer. These are always guaranteed for the original replacement parts. Do not change the programs of the programmable control systems. Always perform the regularly scheduled inspections as specified in the Maintenance manual! 1.5 Operator Training The machine should only be operated by personnel trained in the use of the machine and familiar with the safety instructions. When conducting the training, special attention should be given to the dangers and safety measures. This training should be repeated at regular intervals (at least once per year). The following table shows the skill levels required for operating and maintaining the machine. 8

10 Chapter: Safety Instructions Skill Level Operation and Function Unskilled Basic cleaning, supervised set-up and maintenance. Must not operate the machine. Semi-Skilled Basic daily inspection and cleaning of machine, machine set-up for operations, operating machine (push-button operations only) Skilled Machine set-up for operations, operating machine, maintenance and basic programming Fully Skilled As skilled and fully trained in programming Table 1: Skill levels required for operating and maintaining the machine 1.6 Safety and Test Circuits of the Control Mechanism All generating operations can only be done with the work chamber doors closed. All data input is checked for feasibility and plausibility. The processing cycle is interrupted immediately when malfunctions occur. All malfunctions are reported in the form of on-screen messages. When certain faults occur, the drives are switched off automatically. 1.7 Inspection prior to Starting Work Is the work piece inserted properly? Is the coolant (lubricant) system working properly? Can other persons be endangered by the running machine? 1.8 Safety Instructions for Working with Machine Read and observe all safety instructions in this manual closely. Safety Instructions are given where necessary in the course of a processing cycle. Immediately interrupt the operation when you hear unusual noise or resonance in the machine. These may be due to improper clamping of the tool or workpiece and impair the operating safety! In that case, inspect the workpiece and tool for damage! Only resume the operation when the work piece and tool are intact and undamaged! Never attempt to machine a workpiece without first checking the operation of the machine. Before starting any machining operation or production run, ensure that the machine is operating correctly by performing a trial run using, for example, the FEED RATE OVERRIDE, SINGLE BLOCK or by operating the machine without either a tool and/or workpiece mounted. Failure to confirm the correct operation of the machine may result in the 9

11 Chapter: Safety Instructions machine behaving unexpectedly, possibly causing damage to the workpiece and/or machine itself, or injury to the operator. Before operating the machine, thoroughly check the entered data. Operating the machine with incorrectly specified data may result in the machine behaving unexpectedly, possibly causing damage to the workpiece and/or machine itself, or injury to the user. Ensure that the specified feedrate is appropriate for the intended operation. There is a maximum allowed feedrate specified for the IRP200. The appropriate feedrate varies with the intended operation. If a machine is run at other than the correct speed, it may behave unexpectedly, possibly causing damage to the workpiece and/or machine itself, or injury to the user. When using or applying tool, workpiece or axis compensation functions, thoroughly check the direction and amount of compensation. Operating the machine with incorrectly specified data may result in the machine behaving unexpectedly, possibly causing damage to the workpiece and/or machine itself, or injury to the user. The parameters for the CNC and PMC are factory set. Usually, there is not a need to change them. Machine parameters may only be changed by Zeeko authorised trained personnel. Failure to set a parameter correctly, or changing any of the factory set parameters may result in the machine behaving unexpectedly, possibly causing damage to the workpiece and/or machine itself, or injury to the user. Immediately after switching on the machine, do not touch any of the keys on the user interface or keyboard until the position display or alarm screen appears on the screen. Danger of injury! The workpieces (lenses) and the machining residues may be sharp and could cause skin injuries. If possible, remove the workpiece and the tool from the machine before doing any work in the work chamber. Wear protective gloves when performing any work where you can get in touch with processing residue to prevent injury. Use a brush or wooden/plastic scraper to remove processing residue. Programs, parameters and macro variables are stored in nonvolatile memory in the CNC unit. Usually, they are retained even if the power is turned off. Such data may be deleted inadvertently, however, or it may prove necessary to delete all data from non-volatile memory as part of error recovery. 1 0

12 Chapter: Safety Instructions To guard against the occurrence of the above, and assure quick restoration of deleted data, backup all vital data, and keep the backup copy in a safe place. 1.9 Safety Instructions related to Programming This section covers the major safety precautions related to programming. Before attempting to perform programming, read the following safety instructions related to programming carefully. Coordinate system setting - If a coordinate system is established incorrectly (G54 to G59), the machine may behave unexpectedly as a result of the program issuing an otherwise valid move command. Such an unexpected operation may damage the tool, the machine itself, the workpiece, or cause injury to the user. Positioning by nonlinear interpolation - When performing positioning by nonlinear interpolation, the tool path must be carefully confirmed before performing programmed movements. While positioning in rapid traverse, if the tool collides with the workpiece it may cause damage to the tool, the machine itself, the workpiece, or cause injury to the user. Constant surface speed control - When an axis subject to constant surface speed control approached the origin of the workpiece coordinate system, the C-axis spindle speed may become excessively high. Therefore, it is necessary to specify a maximum allowable C-axis speed. Specifying the maximum allowable speed incorrectly may damage the tool, the machine itself, the workpiece, or cause injury to the user. Absolute/incremental mode - If a program created with absolute values is run in incremental mode, or vice versa, the machine may behave unexpectedly. Plane selection - If an incorrect plane is specified for circular interpolation, helical interpolation, or any canned cycle, the machine may behave unexpectedly. Programmable mirror image - Note that programmed operations vary considerably when a programmed mirror image is enabled Instructions related to Handling This section presents safety precautions related to the handling of the IRP200 machine. Before attempting to perform handling, read the following safety instructions related to handling carefully. Manual operation - When operating the machine manually, determine the current position of the tool and workpiece, and ensure that the movement axis, direction, and feedrate have been specified correctly. Incorrect 1 1

13 Chapter: Safety Instructions operation of the machine may cause damage to the tool, the machine itself, the workpiece, or cause injury to the operator. Manual numeric command - When issuing a manual numeric command, determine the current position of the tool and workpiece, and ensure that the movement axis, direction, direction and command have been specified correctly, and that the entered values are valid. Attempting to operate the machine with an invalid command may cause damage to the tool, the machine itself, the workpiece, or cause injury to the operator. Manual Handle mode - In Manual Handle mode, rotating the handle with a large scale factor such as x1000, causes the selected axis to move rapidly. Careless handling may cause damage to the tool, the machine itself, the workpiece, or cause injury to the operator. Origin/preset operation - Do not attempt an origin/preset operation when the machine is operating under the control of a program. Otherwise, the machine may behave unexpectedly, possibly causing damage to the tool, the machine itself, the workpiece, or cause injury to the operator. Workpiece coordinate shift system - Manual intervention or machine lock may shift the workpiece coordinate system. Before attempting to operate the machine under the control of a program, confirm the coordinate system carefully. If the machine is operated under the control of a program without making allowances for any shift in the coordinate system, the machine may behave unexpectedly, possibly causing damage to the tool, the machine itself, the workpiece, or cause injury to the operator. Manual intervention - If manual intervention is performed during programmed operation of the machine, the tool path may vary when the machine is restarted. Before restarting the machine after manual intervention, confirm the settings of the manual absolute settings, parameters and absolute/incremental mode. Dry run - Usually, a dry run is used to confirm the operation of the machine. During a dry run, the machine operates at dry run speed, which differs from the corresponding programmed feed rate. Note that the dry run speed may sometimes be higher than the programmed feed rate. Program editing - If the machine is stopped, after which the machining program is edited (modification, insertion or deletion), the machine may behave unexpectedly if machining is resumed under the control of that program. It is bad practice to edit (modify, insert or delete), commands from a machining program while it is in use Safety Instructions for working on Electrical Parts Work on electrical system, e.g. connection, must only be performed by qualified technicians or electricians. The electrical cabinet must only be opened by authorized personnel. 1 2

14 Chapter: Safety Instructions Danger for Life! Never perform work on live parts: Turn the MAIN SWITCH to 0 and unplug the machine from the power outlet. With a two-pole voltage meter, test to make sure that the circuit is dead. Faulty fuses must be replaced with fuses of the same amperage and type Safety Instructions related to Daily Maintenance This section presents safety precautions related to daily maintenance of the IRP200 machine. Before attempting to perform daily maintenance, read the following safety instructions related to daily maintenance carefully. The CNC uses batteries to preserve the contents of its memory, because it must retain data such as programs, offsets and parameters even when the power is not applied. If the battery voltage drops, a low battery alarm is displayed on the machine operators screen. When a low battery alarm is displayed, replace the batteries within one week, otherwise, the contents of the CNC memory will be lost. The absolute pulse coders use batteries to preserve its absolute positions even when the power is not applied. If the battery voltage drops, a low battery alarm is displayed on the machine operators screen. When a low battery alarm is displayed, replace the batteries within one week, otherwise, the contents of the CNC memory will be lost. Fuse replacement - Before replacing a blown fuse it is necessary to locate and remove the cause of the blown fuse. For this reason, only personnel who have received approved safety and maintenance training may perform this work. 1 3

15 Chapter: The Machine 5 The Machine 1.13 Technical Data Working Range Workpiece Diameter min.: 20mm max.: 200mm Max. Chuck Bonnet Distance Radius 20mm bonnet: Radius 40mm bonnet: Radius 80mm bonnet: 130mm, 120mm, 70mm Material Mineral glass or similar materials, crystals, glass ceramics, germanium, any metals Tool Radius 20mm, 40mm or 80mm CNC-Axes Axes CNC + Analog Tool Spindle X-Axis Nominal travel: Straightness: compensation) compensation) X-axis alignment: Y-Axis 140mm Vertical: < 10 m over full travel (with software Horizontal: < 10 m over full travel (with software < 5 m over full travel (with software compensation) Nominal travel: 130mm Straightness: Vertical: < 10 m over full travel (with software compensation) compensation) Horizontal: < 10 m over full travel (with software 1 4

16 Chapter: The Machine Y-axis alignment: < 5 m over full travel (with software compensation) Z-Axis Nominal travel: Straightness: compensation) compensation) Z-axis alignment: 130mm Vertical: < 10 m over full travel (with software Horizontal: < 10 m over full travel (with software < 5 m over full travel (with software compensation) A-Axis Range of Movements: 90 The range of motion of the A-Axis is +90 to -45 when the B- Axis is at or within ±40 of the (Horizontal) Home position. A-axis rotation about virtual pivot point: < 25 m B-Axis Range of Movements: +45, -135 B-axis rotation about virtual pivot point: < 25 m C-Axis RPM: TIR: < 5 m H-Axis RPM: TIR: Head pressure: rpm < 20 m 0 4 bar Continuous Noise Level < 50dB (A) Machine Dimensions Width x depth x height: 1655mm x 1635mm x 2160mm 1 5

17 Chapter: The Machine Machine Weight Operation ready: 2000kg 1.14 Power Supply Supply voltage: 3 x 415V at 50/60Hz PEN (standard) 3 x v, 50/60Hz PEN (optional) Power consumption: 8kVA Fusing on the installation side: 3 x 15A, 500V The machinery must only be plugged into a socket which has a protective earthed conductor Compressed Air Supply Min: Max: 5bar 8bar Compressed air supply with maximum pressure 85psi (6bar), maximum pressure is limited to 6.5bar on the pressure controller at the compressed air conditioner Environmental Max. operating temperature: 50 C Max. storage temperature: 70 C Max. humidity: 80% RF 1 6

18 Chapter: Machine Assemblies 6 Machine Assemblies 1.17 Machine Work Chamber Virtual Pivot The figure below shows the work chamber and the virtual pivot with an R40 Bonnet and spray deflector on the H-Axis Plan View of Machine Figure 1: Machine - Work Chamber - Virtual Pivot The figure below shows the top view of the machine. Figure 2: Plan View of Machine 1 7

19 Chapter: Machine Assemblies 1.19 Mechanical Cabinet Figure 3 depicts how the X, Y, Z and C Axes are aligned in the mechanical cabinet of the IRP200/AII.. Figure 3: Machine Axes 1.20 Air Service Unit and CNC Control The air service unit is located within the mechanical cabinet. The CNC control is located in the top left hand side of the electrical cabinet. 1 8

20 Chapter: Machine Assemblies 1.21 Control Panel Figure 4: CNC Control Panel 1 9

21 Chapter: Machine Assemblies # Description # Description 1 FEED RATE OVER-RIDE 8 IN CYCLE Indicator 2 MANUAL/AUTO Select Key Switch 9 RESET / LIMIT OVERRIDE Button 3 E-STOP Button 10 CYCLE STOP Button 4 CYCLE START Button 11 Fault Indicator 5 PUMP On/Off Button + Indicator 12 Reverse JOG Button (-) 6 DRIVE OFF Button 13 Forward JOG Button (+) 7 DRIVE ON Button + Indicator 14 LCD + Touchscreen Table 2: Control Panel Elements 2 0

22 Chapter: Switching ON and Switching OFF the Machine 7 Switching ON and Switching OFF the Machine 1.22 Switching On the Machine Switching On the Electricity at the MAIN SWITCH Turn power on at rear of machine by turning the MAIN SWITCH 90º clockwise. Figure 5: MAIN SWITCH on the Left Hand Side of the Machine Switching On the Computer The computer and LCD display should auto-power on when power is applied to the machine and the MAIN SWITCH is turned to the ON position. If the computer does not auto-power on, please contact Zeeko Ltd. Close and lock the electrical cabinet doors before applying power to the machine Reset the Machine Start the Zeeko GUI from Windows. Ensure E-STOP is released on CNC Control Panel. Press F8 SYS RESET on Zeeko GUI button. Push the white DRIVE ON button for a few seconds to turn the drives on (the button will become illuminated). Figure 6: 'DRIVE ON# Button on CNC Control Panel Switching On the Compressed Air Supply From the external valve on the machine, switch on the compressed air supply to the machine Switching On the Slurry (Coolant) Supply From the external valve on the machine, switch on the centrifuge and the pump of the slurry (coolant) supply. 2 1

23 Chapter: Switching ON and Switching OFF the Machine 1.23 Switching Off the Machine Shutting Down the Computer Push the red DRIVE OFF button on the CNC control panel until drives are off (Zeeko GUI will display error message saying 3 Drives OFF ). Figure 7: 'DRIVE OFF' Button on CNC Control Panel Close down any programs that may be open (not including the Bosch or Zeeko programs Exceed, CPL, Bosch X Terminal, Zeeko GUI, and Zeeko TPG). Do not shut down the PC from the Windows START-SHUT DOWN option. If by mistake you do shut down the machine from Windows START-SHUT DOWN, wait until PC is shut down, wait for one minute and turn the machine off by the MAIN SWITCH. When next turning the machine on, only use the MAIN SWITCH. In the case of any problem, please contact Zeeko Ltd Switching Off the Compressed Air Supply Switch off the compressed air supply to the machine Switching Off the Slurry (Coolant) Supply Switch off the centrifuge and the pump of the slurry (coolant) supply Switching Off the Electricity at the MAIN SWITCH When Windows has shut down, turn off the master MAIN SWITCH at the left hand side of the machine by turning the switch 90º anti-clockwise. Figure 8: MAIN SWITCH at the rear of the Machine 2 2

24 Chapter: Using Canned Programs 8 Using Canned Programs A variety of pre-defined CNC programs are available to the user from the RUN Page: Figure 9: RUN Menu Most of these canned programs (HOME, LOAD, TOOL, UTIL1 & UTIL2) are created by the TPG software and will be covered in the GUI section of the Software Manual. Simply selecting the desired program option will cause the program to become activated in the PROGRAM BUFFER. Pressing the CYCLE START button will start the program. In some circumstances the canned program may not be loaded. Please review the header of the file shown in the POGRAM BUFFER to ensure that the chosen canned program has loaded. (see section Error! Reference source not found. for how to delete rograms from the memory) If the canned program is interrupted and is not terminated by the M30 command then the program can remain in memory. This will be indicated in the POGRAM BUFFER display by the failure to show the normal Program Launch CNC program (see section Error! Reference source not found. for how to delete rograms from the memory). 2 3

25 Chapter: Setting Workpiece Co-ordinate System 9 Setting Workpiece Co-ordinate System If the Home position has been nominally set with X&Y at 0-0 then use the canned HOME program on the GUI RUN page to position the two references nominally co-axial. Exit the RUN page and enter the MANUAL page form the GUI MAIN menu. Use the Z-axis MPG control to move to Z-axis until a small gap of around 0.25mm exists between the 2 reference spheres. As both reference surfaces are solid, take care when manually moving the Z-axis. Exit the MANUAL page and enter the GUI PROG page. Make sure that the MDI option has been selected. Exit the PROG page and enter the GUI RUN page. Select the ZTOP option. Watch for the PROGRAM BUFFER screen displaying the Press Cycle Start Button. Press the CYCLE START button. A Total of 5 touch-on routines will be performed. DO NOT switch modes (e.g. PROG, MDI, DIR, EDIT or INPUT) while the Touch-On program is running. If any of these options are selected the program execution will be suspended. It can be re-started by returning to the RUN page and pressing CYCLE START. When the PROGRAM BUFFER displays the message REVIEW PROGRAM PAGE select CLOSE from the RUN page and enter the PROGRAM page. Review each of the 5 touch on values (located in memory position P100 to P104) and determine the desired average value for touch-on. Enter this value into the G54 Z OFFSET field. Press the SET button to update the G54 Z OFFSET value. 2 4

26 Chapter: Setting Workpiece Co-ordinate System Figure 10: PROGRAM Menu The machine co-ordinate system has now been set such the Z=0mm is the contact point between the workpiece and the polishing head. Figure 11: PROGRAM Menu 2 5

27 Chapter: Manual Control of Machine Axes 10 Manual Control of Machine Axes The machine can be manually controlled in three different ways: Entering and actioning G code commands in MDI mode. Using one of the three basic manual modes (JOG, INC or MPG) Using Tool Spindle and Work Spindle commands MDI Mode In MDI mode, G code commands can be manually entered and actioned. Select the PROG tab of the GUI MAIN menu. Select the MDI tab (see figure below). MDI Buffer Window Command Line Mode Indicator Figure 12: PROGRAM Menu: MDI Tab Enter a G code command in the COMMAND LINE followed by ENTER. The command as typed (less redundant spaces) should be displayed in the MDI BUFFER. In case the command does not appear in the MDI BUFFER, Press the EDIT followed by the MDI tab and re-enter G code command in the COMMAND LINE followed by ENTER Press the CYCLE START button on the CNC control panel Basic Manual Modes In the GUI MANUAL menu, the user can select between the following three basic manual modes: JOG INC MPG 2 6

28 Chapter: Manual Control of Machine Axes JOG Mode Figure 13: MANUAL Menu The axis to be jogged must be selected from the MANUAL screen on the GUI. Pressing the JOG + or JOG buttons on the CNC control panel will cause the selected axis to move in the stated direction. Movement of the axis will be continuous while the command button is depressed. The speed of motion is independent of the multiplier selected (i.e. x1, x10, x100) INC Mode In this mode pressing the jog keys causes the selected axis to move in the stated direction by the amount of the selected multiplier (i.e. x1, x10, x100 microns). The axis will move the stated amount on each key press. Continued depression of a jog button will still only result in a single incremental move. The key must be released and depressed again to cause another incremental move to occur. The increments in the multiplier are defined as follows: X1 = 1μm increments X10 = 10μm increments X100 = 100μm increments MPG Mode This allows the Manual Pulse Generator (MPG) hand wheel to be used to move the selected axis. The highlighted axis will move in increments as specified in the multiplier Tool Spindle and Workpiece Spindle Commands The tool spindle and workpiece spindle be manually operated by selecting options from the TOOL SPINDLE (S) and WORKPIECE SPINDLE (C) section of the GUI MANUAL page. 2 7

29 Chapter: Manual Control of Machine Axes Figure 14: MANUAL Menu TOOL SPINDLE (H) Sections The options available are: FWD : STOP : REV : DEC : Causes the H-axis to rotate in the M03 direction at the last speed defined either in a CNC program or the MDI COMMAND LINE (see section 9.1 in this manual). If no speed has been defined the spindle will remain static. Causes the spindle to stop rotating. Causes the spindle to rotate in the M04 direction at the last speed defined either in a CNC program or the MDI COMMAND LINE (see section 9.1). If no speed has been defined the spindle will remain static. If the spindle is rotating then the speed will be decreased by 5% for each press. 100% : Resets the spindle speed to the last defined speed. INC : If the spindle is rotating then the speed will be increased by 5% for each press WORK SPINDLE (C) Sections The options available are: FWD : STOP : REV : Causes the C-axis to rotate in the M23 direction at the last speed defined either in a CNC program or manually by program MDI COMMAND LINE (see section 9.1 in this manual). If no speed has been defined the spindle will remain static. Causes the spindle to stop rotating. Causes the C-axis to rotate in the M24 direction at the last speed defined either in a CNC program or manually by program MDI 2 8

30 Chapter: Manual Control of Machine Axes DEC : COMMAND LINE (see section 9.1). If no speed has been defined the spindle will remain static. If the spindle is rotating then the speed will be decreased by 5% for each press. 100% : Resets the spindle speed to the last defined speed. INC : If the spindle is rotating then the speed will be increased by 5% for each press. 2 9

31 Chapter: Checking and Setting X&Y Zero Position 11 Checking and Setting X&Y Zero Position Checking and setting the X and Y zero position is just necessary to perform periodically. Switch off the air supply. Insert the reference tooling into the H-axis head. Figure 15: Reference Bonnet Insert the reference tooling ball into the chuck of the C-axis Figure 16: Reference Tooling Ball Set the workpiece co-ordinate system (see section 9) After setting the workpiece co-ordinate system, select the TPG option from the MAIN menu. From the TPG MAIN menu select the METROLOGY option to display the On Machine Probing menu. 3 0

32 Chapter: Checking and Setting X&Y Zero Position Figure 17: ON MACHINE PROBING Menu Set the following setting for each of the options shown on the menu: Option Setting Comment Estimated Radius (mm) Bonnet/Cloth 40.0mm Enter the actual known radius of the reference tooling (typically 40mm) No. of Probe Positions is typically sufficient to characterize the X or Y position of the centre of the tooling. A smaller value will speed up the process, a greater value will marginally improve accuracy. Probe Clearance 0.2 For hard tooling with known accurate radii 0.2mm is a sufficient clearance. If there is any doubt about the radii then increase this value. The probing time will increase but with less risk of a collision. Probe Diameter 100 Enter the known diameter of the reference tooling mounted into the chuck. In this example a master convex optic was used with a 50mm radius (100mm) 3 1

33 Chapter: Checking and Setting X&Y Zero Position Probe Offset 0 To simulate the effect of changing a G=54 offset a value can be entered here but is not recommended Probing Diameter 40 This defines the extent to which the reference tooling is probed. The value entered should be the maximum possible where the contact point remains on a known accurate radius. Probing Feed Rate 5 5 is a safe and accurate value. To speed things up a value of 10 could be entered but with a potential loss of accuracy and increased risk of collision. Probing Type Bonnet Probe Probing Direction X/A Selecting X/A will probe about the X- axis. To set the Y-axis G54 simply select option Y/B Table 3: ON MACHINE PROBING Menu Options Settings Review the settings to ensure that you have not made a mistake, pay particular attention to the 2 reference diameters entered and the probing diameter. If satisfied with the settings then generate the CNC probing file by pressing (F2)-GENERATE PROBING CNC. Switch focus back to the machine GUI software. From the RUN menu, select the UTL1 canned program option. Ensure that the PROGRAM BUFFER window shows the program created is correct (check the date and time in program header). If the date and time are not correct, see section 1.56 for how to delete programs from memory. If satisfied with the loaded program and that the correct ZTOP position is defined the metrology program can be run by pressing the CYCLE START button on the control panel. 3 2

34 Chapter: Checking and Setting X&Y Zero Position On completion (or during if desired), change focus to the TPG software by using the toolbar (do not use the GUI MAIN menu TPG option). From the METROLOGY menu select the (F3) GRAPH RESULTS command button. Figure 18: ZTOPDATA GRAPH Menu If no graph is displayed ensure that the location of the ZTOPDATA.txt file is correctly specified in the PATH FOR ZTOPDATA.txt dialog box and that the Y-AXIS graph option is set to Z and X-AXIS graph option is set to X (or Y as appropriate). Press F2 REFRESH GRAPH to refresh the display. The graph will show the curvature of the surface measured. In order to determine the measured radius and X (or Y) offset it is necessary to subtract the radius. Select the APPLY MODIFIERS option. Select the X option. This does not apply to the machine X-axis but the graph axis and it is the axis about which the radius will be removed. Set the RADIUS TO SUBSTRACT value to 40mm (or the known radius of the reference tooling). Set the TRIAL OFFSET to 0. Enter the known CURRENT G54 (The current G54 offset values can be checked in the GUI SETUP menu: OFFSET tab G54 tab) setting of the X-axis (or Y-axis). Press F2 to refresh the display. 3 3

35 Chapter: Checking and Setting X&Y Zero Position Figure 19: Typical Graph Displayed When an Offset Error is Present Typically the graph will now show a straight line but tilted. Any curvature is a sign of an erroneous radius entered and any tilt is an indication of the degree of offset error in the selected machine axis (X or Y). If reference tooling has been used and there is any significant curvature to the graph, please re-check the values entered and re-measure if necessary. Assuming the line is nominally straight then adjust the TRAIL OFFSET value to try and position the line horizontal on the graph (remember to press F2 to refresh the display after each new value is entered). Figure 20: Typical Sequence of Error Plot Ending Up with a Nominally Level Graph In the graphs shown above the 1st setting has an existing machine offset that is too low, the second graph the proposed value is too high, and the 3rd graph is set approximately correct. When you are satisfied that the line is nominally correct read the NEW G54 value and enter that directly into the machine control settings. 3 4

36 Chapter: Checking and Setting X&Y Zero Position Figure 21: GUI Screen Showing G54 Offset Values If the correction applied is significant (i.e. more than a 10-20m) it is worth repeating the process. If the process is repeated, ensure that the CURRENT G54 value is updated on the ZTOPDATA GRAPH menu. It may be necessary to refine the TRAIL G54 value and repeat the process. Figure 22: Result with a Revised G54 Offset Value (residual is still slightly out of level) In this example the TRAIL G54 value needed an adjustment of -0.02mm to give a result of: 3 5

37 Chapter: Checking and Setting X&Y Zero Position Figure 23: Result after Optimisation of the G54 Value (showing a nominally level result) The NEW G54 value should be entered into the machine control (for further instructions see section 24). Figure 24: GUI Screen Showing the Final G54 Value If the adjustment made is less than 20μm then it is not necessary to repeat the process. When the X-axis has been corrected, repeat the exercise but with he Y- axis as the chosen axis in the TPG software. Remember to re-enter the appropriate CURRENT G54 values. 3 6

38 Chapter: Checking for Virtual Pivot Errors in the A or B Axes 12 Checking for Virtual Pivot Errors in the A or B Axes This can be performed without the reference tooling but will be less accurate and include additional bonnet errors. Switch off the air supply. Insert the reference tooling into the H-axis head. Figure 25: Reference Bonnet Insert the reference tooling ball into the chuck of the C-axis Figure 26: Reference Tooling Ball Set the workpiece co-ordinate system (see section 9) After setting the workpiece co-ordinate system, select the TPG option from the MAIN menu. From the TPG MAIN menu select the METR option to display the METROLOGY menu. 3 7

39 Chapter: Checking for Virtual Pivot Errors in the A or B Axes Figure 27: ON MACHINE PROBING Menu Under the Probing Type select Virtual Pivot Probing Enter the following value (see Table 4) for each of the options shown on the menu: Option Setting Comment Estimated Radius (mm) Bonnet/Cloth 40.0mm Enter the actual known radius of the reference tooling (typically 40mm) No. of Probe Positions is typically sufficient to characterise the VP-A or VP-B. A smaller value will speed up the process, a greater value will improve accuracy. Probe Clearance 0.2 For hard tooling with known accurate radii 0.2mm is a sufficient clearance. If there is any doubt about the radii then increase this value. The probing time will increase but with less risk of a collision. Probe Diameter 100 Enter the known diameter of the reference tooling mounted into the chuck. In this example a master convex optic was used with a 50mm radius (100mm) 3 8

40 Chapter: Checking for Virtual Pivot Errors in the A or B Axes Option Setting Comment Probe Offset 0 To simulate the effect of changing a G=54 offset a value can be entered here but is not recommended Probing Feed Rate 3 (Bosch) 5 (Fanuc) 5 is a safe and accurate value. To speed things up a value of 10 could be entered but with a potential loss of accuracy and increased risk of collision. VP Probing Angle 30 A value should be selected that will safely characterize the VP position over as wide an angle as possible. Probing Type VP Probe Probing Direction X/A Selecting X/A will probe about the A- axis. To probe about the B axis simply select option Y/B Table 4: ON MACHINE PROBING Menu Options Settings Review the settings to ensure that you have not made a mistake, pay particular attention to the 2 reference diameters entered and the probing diameter. If satisfied with the settings then generate the CNC probing file by pressing (F2)-GENERATE PROBING CNC. Switch focus back to the machine GUI software. From the RUN menu, select the UTIL2 or METR. canned program option. 3 9

41 Chapter: Checking for Virtual Pivot Errors in the A or B Axes Figure 28: RUN Menu: UTIL2 Tab Ensure that the PROGRAM BUFFER window shows the program created (check the date & time). If the date and time are not correct then it is possible that an old program has lodged in memory. If this is the case then see section 1.56 for how to delete programs from the memory. If satisfied with the loaded program and that the correct ZTOP position is defined the metrology program can be run by pressing the CYCLE- START button on the control panel. On completion (or during if desired), change focus to the TPG software by using the toolbar (do not use the GUI MAIN menu TPG option). From the METR menu select the (F3) GRAPH RESULS command button. Ensure that the Y-AXIS radio button is set to Z and that the X-AXIS option is set to A (or B ), and that the APPLY MODIFIERS option is deselected. 4 0

42 Chapter: Checking for Virtual Pivot Errors in the A or B Axes Figure 29: ZTOPDATA GRAPH Menu If no graph is displayed ensure that the location of the ZTOPDATA.txt file is correctly specified in the PATH FOR ZTopDATA.txt dialog box and that the Y-AXIS graph option is set to Z and X-AXIS graph option is set to A (or B as appropriate). Press (F2) REFRESH GRAPH to refresh the display. Ideally the graph should be nominally a straight-horizontal line. The example above suggests that the A-axis is out of alignment by approximately 200µm (Z-Axis reads for A-Axis at -30 to for A-Axis at +30 ). It is recommended that the error be typically less than 50µm. If the value is less than 200µm it is possible to apply correction factors from within the CNC to compensate for the error. If the error is greater than 200µm, it is recommended that the virtual pivot be mechanically adjusted. Contact Zeeko Limited for further information. 4 1

43 Chapter: Preparing the Bonnet 13 Preparing the Bonnet 1.27 Fitting the Bonnet It is essential when fitting the bonnet that it locates correctly in the H-axis mounting. Failure to locate correctly will cause unnecessary run-out and cause problems in polishing. Switch off the air supply to the head. Removing the bonnet or polishing tool with air pressure applied may cause serious damage and/or injury. Use the Tool canned CNC program from the GUI RUN page to position the machine axes at a suitable position to replace the bonnet. Remove the slurry guard from around the H-axis by unscrewing from the mounting. Slurry Guard Figure 30: Slurry Guard Using the dedicated tool remove the bonnet retaining ring and remove the existing bonnet. Bonnet Retaining Ring Figure 31: Bonnet Retaining Ring 4 2

44 Chapter: Preparing the Bonnet Ensure that the plastic compression ring is secured on the replacement bonnet. If the ring is not on the removed bonnet it may be located inside the retaining ring. Place the replacement bonnet into the location ring on the H-axis. Before fitting the retaining ring, ensure that the bonnet is free to rotate, this will ensure that it is seated properly (when clamped it will not rotate). Replace the retaining ring and hand tighten. Use the dedicated tool to tighten the retaining ring just enough to prevent air leakage when in operation. DO NOT OVERTIGHTEN. Dress the bonnet as necessary. Replace the slurry guard Dressing the Bonnet/Cloth When using polyurethane cloths it is advisable to perform a dressing operation particularly when used for corrective polishing. This will true the surface and remove local irregularities as a result of gluing the cloth to the rubber membrane of the bonnet. It is advisable that this operation is performed without the Slurry Guard fitted. The cloth should be trimmed to the desired diameter before dressing (see section 1.30). From the UTILITIES Menu of the TPG software select the options as appropriate to the bonnet/cloth being used (the screen displayed below should appear). Figure 32: TOOL DRESSING Menu 4 3

45 Chapter: Preparing the Bonnet Option Setting Comments Dress Tool Diameter (mm) 40mm (e.g.) Enter the diameter of the tool to be used for dressing Depth of Cut/Feed (mm) 0.05mm (e.g.) Select a value appropriate to the cloth to be dressed. Use small values to obtain the best finish, larger values when the amount of error and cloth available warrants a greater removal. This sets the depth of cut that will occur on each Feed of the Z axis. No. Of Passes/Cut 2 (e.g.) Set the number of passes that will occur before the Z axis is indexed to the next cut. No. Of Pass on Final Cut 3 (e.g.) It is advisable that a greater number of passes are used on the final cut as the cloth can have a tendency to relax. No of Cuts 3 Sets the total number of cuts that will occur (i.e. number of Z increment feeds) A Angle Start (degrees) 42degs (e.g.) Select an angle that is sufficient to allow the tool to pass completely over the cloth being dressed. A Angle Finish (degrees) -42degs (e.g.) This should be typically set to the same negative value as the start position. In some cases it may be necessary to enter a different value (such as 0degs) Total Depth of Cut (mm) xxx This value is calculated based on:- No of cuts x depth of cut Feed Rate (mm/sec 5 (e.g.) A slow feed is preferred due to the nature of polyurethane. However greater values may be used subject to experience. 4 4

46 Chapter: Preparing the Bonnet Head Speed (rpm) 1000 (e.g.) Value may be changed based on experience C Axis Speed (rpm) 750 (e.g.) Value may be changed based on experience Table 12.2: TOOL DRESSING Menu Settings When satisfied with the settings press the (F2) GENERATE CNC button. The user is then prompted to enter a filename. The default is O1999 and which can be loaded by the Program Launcher of the CNC. Another program name can be used if manual loading of the CNC is desired. Save file. Position the X axis to the radius (i.e. Diameter/2) of the tool (20mm in this example). This can be done manually or via the COMMAND LINE in MDI mode (see section 1.24) (using the command G00 X20). Set the head pressure to the desired operating pressure for the chosen bonnet. With the X axis in this position manually move the Z-axis close to the bonnet and perform a standard Z-Top operation (see section 9). Return the axes to the Home position using the canned programme of the GUI RUN page. Switch on the slurry supply and execute the CNC program by pressing the CYCLE START button (ensure the correct program is loaded into the buffer by the time and date fields) Moulding Polyurethane Bonnet Polishing Cloths To mould polyurethane polishing cloths to the appropriate radius before gluing to the rubber bonnet membrane follow the procedure below: Place the base of the stainless steel moulding fixture on a hot plate, at approximately 85 C. Allow the tooling to heat for approximately 10-15minutes. Once heated place a layer of tissue paper or aluminium foil on top of the tooling. This will prevent the polyurethane from melting onto the dye in the event of overheating. Cut a circular piece of Polyurethane to a nominal diameter of 60mm. Place on top of the moulding fixture base and place the top of the fixture onto the polyurethane. Loosely insert fixing bolts. Allow the heat to start to penetrate the Polyurethane. Insert the fixing screws and progressively tighten each screw keeping the top piece parallel to the base. Tightening the screws evenly and slowly helps prevent the Polyurethane from buckling. 4 5

47 Chapter: Preparing the Bonnet Figure 33: R40 Cloth Forming Fixture Leave the fixture on the hot plate for approximately 15-20minutes. Then allow to cool naturally. It is advisable to always have a cloth moulded ready for use. Leaving one clamped in the fixture will also help retain the desired shape. Before use the moulded polyurethane should then be trimmed to a diameter slightly larger than that required. The final trimming to the desired size will be performed on the machine Trimming the Cloth Insert the diamond/tungsten cutting tool into the Ø12 x Ø25 collet. Figure 34: Trimming Tool & Ø25 x Ø12mmCollet Adapter Place the cutting assembly into the C axis of the machine, ensuring that the cutting tool is orientated correctly for cutting. Put the bonnet in the machine with the Slurry guard removed. Launch the TPG software and select the Tim Cloth Tab of the Utilities menu. 4 6

48 Chapter: Preparing the Bonnet Figure 35: Trim Cloth Menu (Via Utilities Menu) Select the parameters as appropriate. It is recommended that the Depth of Cut be set slightly less than the actual thickness of the cloth (approx 0.2mm) to avoid damaging the rubber bonnet. When satisfied with the parameters select the {F1} Create CNC File command button (or press the F1 key). 2 Programs will be generated (1006.txt and O1007.txt) and a message displayed giving instruction on their use. Figure 36: Trim Cloth Instructions From the Machine GUI run the O1006 canned program (UTIL1 or C.PROBE), this will position the machine at the correct angle to generate the desired diameter of cloth. 4 7

49 Chapter: Preparing the Bonnet Figure 37: GUI RUN Page Manual move the Z Axis until it just contacts the surface of the cloth and press the SET Z button on the PROG menu. Figure 38: Setting the Z=Zero (G54) position Select and run the O1007.txt UTIL2- METR canned program to trim the cloth. Use slurry or water to cool the cutting tip during trimming. 4 8

50 Chapter: Measuring the Bonnet Cloth Radius 14 Measuring the Bonnet Cloth Radius 1.31 Determining the Bonnet Radius A preliminary radius for the bonnet is best measured using the reference ball mounted in the workpiece chuck or a known accurate radius workpiece. The bonnet should be pressurised at its specified operating pressure. Insert the reference tooling ball into the chuck of the C-axis Figure 39: Reference Tooling Ball Use the canned HOME program on the GUI RUN page to position the machine at X=0, Y=0. Set the workpiece co-ordinate system (see section 9 after setting the workpiece co-ordinate system, select the TPG option from the MAIN menu. From the TPG MAIN menu select the METR option to display the METROLOGY menu. Figure 40: TPG 'METROLOGY' Menu Set the following setting for each of the options shown on the menu. 4 9

51 Chapter: Measuring the Bonnet Cloth Radius Option Setting Comment Estimated Bonnet/Cloth Radius (mm) 40.5mm Enter the best guess radius of the bonnet. Using a slightly greater radius value will reduce the risk of collision. The value can be refined after the first pass measurement. No. of Probe Positions is typically sufficient to characterise the X or Y position of the centre of the tooling. A smaller value will speed up the process, a greater value will marginally improve accuracy. Probe Clearance 0.2 For hard tooling with known accurate radii 0.2mm is a sufficient clearance. If there is any doubt about the radii then increase this value. The probing time will increase but with less risk of a collision. Probe Diameter 100 Enter the known diameter of the reference tooling mounted into the chuck. In this example a master convex optic was used with a 50mm radius (100mm) Probe Offset 0 To simulate the effect of changing a G=54 offset a value can be entered here but is not recommended Probing diameter 55 This defines the extent to which the reference tooling is probed. The value entered should be the maximum possible where the contact point remains on a known accurate radius. Probing Feed Rate 5 5 is a safe and accurate value. To speed things up a value of 10 could be entered but with a potential loss of accuracy and increased risk of collision. Probing Type Bonnet Probe Probing Direction X/A Selecting X/A will probe about the X axis. To set the Y axis G54 simply select option Y/B Table 5: Settings for the Options Shown on the TPG METROLOGY Menu 5 0

52 Chapter: Measuring the Bonnet Cloth Radius Review the settings to ensure that you have not made a mistake, pay particular attention to the 2 reference diameters entered and the probing diameter. If satisfied with the settings then generate the CNC probing file by pressing (F2) GENERATE PROBING CNC. Switch focus back to the machine GUI software. From the RUN menu, select the UTIL2 - METR canned program option. Figure 41: RUN Menu Ensure that the PROGRAM BUFFER window shows the program created (check the date & time). If satisfied with the loaded program and that the correct ZTOP position is defined the metrology program can be run by pressing the CYCLE START button. On completion (or during if desired), change focus to the TPG software by using the toolbar (do not use the GUI MAIN menu TPG option). From the METROLOGY menu select the (F3) GRAPH RESULTS command button. Figure 42: 'ZTOPDATA Graph' Menu (Showing Result of Bonnet Probing) 5 1

53 Chapter: Measuring the Bonnet Cloth Radius If no graph is displayed ensure that the location of the ZTOPDATA.txt file is correctly specified in the PATH FOR ZTOPDATA.txt dialog box and that the Y-AXIS graph option is set to Z and X-AXIS graph option is set to X (or Y as appropriate). Press (F2) REFRESH GRAPH to refresh the display. The graph will show the curvature of the surface measured. In order to determine the measured radius it is necessary to subtract the estimated radius. Select the APPLY MODIFIERS option. Select the X option. This does not apply to the machine X-axis but the graph axis and it is the axis about which the radius will be removed. Set the RADIUS TO SUBSTRACT value to 40.5mm (or the estimated radius of the bonnet). Set the TRIAL OFFSET to 0. Enter the known CURRENT G54 setting of the X-axis (or Y-axis). Press F2 to refresh the display. Figure 43: ZTOPDATA GRAPH Menu (Showing Result of Bonnet Probing) Ideally the profile should be nominally flat and horizontal. If the line is tilted it suggests that the X (or Y0) G54 offset is not correctly set (see section 11 on how to test. Assuming the line is nominally horizontal try different radius values until the line has flat extremities. e.g. 5 2

54 Chapter: Measuring the Bonnet Cloth Radius Figure 44: ZTOPDATA GRAPH Menu (Showing Result of Bonnet Probing) The radius value can then be changed in the TPG software and a revised probing routine generated. After re-running the metrology probing routine a result similar to that shown below should result. Figure 45: ZTOPDATA GRAPH Menu (Showing Result of Bonnet Probing) 5 3

55 Chapter: Measuring the Bonnet Cloth Radius The actual measured radius of a bonnet/cloth may differ slightly from its effective radius of operation due to virtual pivot errors. While the above radius is generally acceptable a refinement of the effective radius can be performed by performing a probing routine which emulates how the bonnet/cloth will be used during polishing 1.32 Determining the Effective Bonnet/Cloth Radius Using the TPG METROLOGY probing routine to determine the bonnet & cloth radius is a good starting point for determining the bonnet/cloth radius. However the influence of the virtual pivot (& its corrections) change slightly the way in which the bonnet/cloth behaves in terms of its radius. A further refinement of the bonnet/cloth radius can be achieved by using the NON LINEAR CORRECTION capability given in each toolpath (except Raster). By reviewing the residual probing errors and adjusting the bonnet/cloth radii, the residual errors can be reduced to a minimal value. While this is not an essential task, it will reduce the degree of corrections applied and generally improve the overall accuracy of performance. This routine should only be performed on a bonnet and cloth which has been trimmed on the machine to cloth radius is constant. Using the bonnet/cloth radii values as measured in the probing routine, perform a NON LINEAR CORRECTION probing routine from the chosen toolpath. Set the part parameters as appropriate in the TPG PART PARAMETER menu: Figure 46: TPG PART PARAMETER Menu 5 4

56 Chapter: Measuring the Bonnet Cloth Radius From the SPIRAL POLISH menu enter the appropriate parameters as if you were about to polish a part as loaded into the workpiece chuck. It is recommended that the PRECESS ANGLE is set to 0degs and the number of PRECESS POSITIONS to 1. Figure 47: TPG SPIRAL POLISH Menu Select the (F4) NON LINEAR CORRECTION command button to go to the following menu: Figure 48: NON LINEAR CORRECTION Menu Check the APPLY NON-LINEAR CORRECTION option. Select either 7 or 9 points as the number of probing points ( 9 is recommended). Enter a range of value for each of the 9 points (4 either side of centre). 5 5

57 Chapter: Measuring the Bonnet Cloth Radius The X value is the actual machine X value and will need to be greater than the actual X value on the part. Select SINGLE GEOMETRY and ONE PASS. Generate the CNC probing routine by pressing (F2) CREATE CNC PROBING FILE. Switch focus to the GUI software. Ensure that a ZTOP G54 position has been correctly set (see section 8). Figure 49: RUN Menu: UTIL2 Tab Select the canned METR tab from the RUN menu. Check that the correct program has been loaded by reviewing the programs title and date & time. This can be performed without the reference tooling but will be less accurate and include additional bonnet errors. Press the CYCLE START button to run the program. When the metrology probing CNC program has completed switch focus to the TPG program. Select the (F4) NON-LINEAR CORRECTIONS command button from the SPIRAL (or chosen toolpath) menu, the NON-LINEAR CORRECTIONS menu should be displayed. 5 6

58 Chapter: Measuring the Bonnet Cloth Radius Figure 50: NON-LINEAR CORRECTIONS Menu: (F3) ZEEKO POWER COMPENSATION Tab Select the (F3) ZEEKO POWER COMPENSATION tab. The user will be prompted to navigate to the ZTOPDATA.txt file. Figure 51: OPEN FROM CORRECTION FILE Menu On completion of processing the ZTOPDATA data the NON LINEAR CORRECTIONS PLOT will be displayed. i.e.: 5 7

59 Chapter: Measuring the Bonnet Cloth Radius Figure 52: Bonnet/Cloth Combined Radius = 40.5 If the graph shows any significant residual curvature then the effective combined radius of the bonnet & cloth is incorrect. Based on the part geometry and residual error curvature adjust the bonnet or cloth radius value in the TPG software (TPG MAIN menu: PART PARAMETERS tab TOOL PARAMETERS. Workpiece Geometry Residual Geometry Error Action Convex Decrease Bonnet/Cloth Radius Convex/Plano Concave Increase Bonnet/Cloth Radius Convex Increase Bonnet/Cloth Radius Concave Concave Decrease Bonnet/Cloth Radius Table 6: Actions to be taken for Different Workpiece Geometry / Residual Error Geometry Combinations 5 8

60 Chapter: Measuring the Bonnet Cloth Radius Figure 53: Combined Bonnet/Cloth Radius = 40.0mm Figure 54: Combined Bonnet/Cloth Radius = 39.0 If the curve shows a lack of symmetry then this is an indication of an error in the X G54 offset value (see section 0) Repeat the process adjusting the combined bonnet & cloth radii (and the G54 X-axis offset [see section 0]), until a nominally straight, horizontal residual error is obtained. E.g.: 5 9

61 Chapter: Measuring the Bonnet Cloth Radius Figure 55: Combined Bonnet/Cloth Radius =38mm & G54 X Offset Reduced by 0.1mm A perfectly straight, horizontal line should not be expected. The majority of bonnets and cloths will all suffer from some local variations. Symmetry and minimal curvature (typically less than 100μm) is an acceptable condition as shown above. The Y-axis scale on the graph of non-linear will auto scale to the data range to be displayed. 6 0

62 Chapter: Checking and Adjusting Workpiece Run-Out 15 Checking and Adjusting Workpiece Run- Out It is essential that the run-out of the face of a workpiece is minimised. Any run-out of the face will tend to cause some lack of symmetry and astigmatism in the polished workpiece. The extent of the allowable run-out varies depending on the number of passes or total dwell time. Ideally the run-out should be maintained below 5μm if possible. The run-out of the face can be measured using a conventional dial indicator mounted to a magnetic gauge stand and fixed to the C/Z-axis cover plate. The manual machine controls can be used to rotate the part under the gauge. An alternative method is available using the load cell and on-machine probing capability of the machine. This process does not require any additional tooling. From the METROLOGY menu of the TPG software select the RUN OUT PROBING option. Figure 56: Run Out Probing Parameter Settings 6 1

63 Chapter: Checking and Adjusting Workpiece Run-Out Figure 57: Run Out of Workpiece Assessed Using on Machine Probing TIP: If the run-out is greater than that desired, try rotating the workpiece in the chuck and re-measuring. 6 2

64 Chapter: Performing a Non-Linear Correction 16 Performing a Non-Linear Correction This option is not available in Raster polishing mode. When the appropriate part parameters have been defined and the chosen toolpath (i.e. Spiral or Precessions mode) and options have been selected, it is recommended to perform a non-linear correction probing routine. Performing this measurement will significantly reduce the errors caused by minor errors in the polishing bonnet and part geometry affecting the accuracy of toolpath generated relative to the surface being polished. Select the (F4) NON LINEAR CORRECTION command button to go to the following menu: Figure 58: NON LINEAR CORRECTION Menu Check the APPLY NON-LINEAR CORRECTION option. Select either 3, 5, 7 or 9 points as the number of probing points ( 9 is most accurate but slowest, 3 is least accurate but fastest). Enter a range of value for each of the 9 points (4 either side of centre). The X-axis value is the actual machine X-axis value and will need to be greater than the actual X-axis value on the part. Select SINGLE GEOMETRY and ONE PASS. Generate the CNC probing routine by pressing (F2) CREATE CNC PROBING FILE. Switch focus to the Zeeko machine control software. Ensure that a ZTOP G54 position has been correctly set (see: 8 Setting Workpiece Co-ordinate System ). 6 3

65 Chapter: Performing a Non-Linear Correction Figure 59: RUN Menu: UTIL2 -METR Tab Select the canned METR tab from the RUN menu. Check that the correct program has been loaded by reviewing the programs title and ate & time. Press the CYCLE START button to run the program. When the metrology probing CNC program has completed switch focus to the TPG program. Select the (F4) NON-LINEAR CORRECTIONS command button from the chosen toolpath) menu, the NON-LINEAR CORRECTIONS menu should be displayed. Figure 60: NON-LINEAR CORRECTIONS Menu: (F3) ZEEKO POWER COMPENSATION Tab Select the (F3) ZEEKO POWER COMPENSATION tab. The user will be prompted to navigate to the ZTOPDATA.txt file. 6 4

66 Chapter: Performing a Non-Linear Correction Figure 61: OPEN FORM CORRECTION FILE Dialog Box On completion of processing the ZTOPDATA data the NON LINEAR CORRECTIONS PLOT will be displayed as shown on the next page. Figure 62: Plot of Non-Linear Corrections Showing an Acceptable Symmetrical Error Plot with Small Deviation The shape of the graph above indicates a bonnet with a slightly non spherical shape. Ideally the plot should show a symmetrical error plot with an overall deviation of less than 200µm. If the deviation is tilted then it suggests that the bonnet, part or current X axis G54 offset is incorrectly set. If this is the case then see section 0 for details on how to check and adjust. If the deviation is greater than approximately 200um then it is most likely that an error exists on the defined bonnet/cloth effective radius or the part radius. If this is the case then refer to section 0 for details on how to check and adjust the values. 6 5

67 Chapter: Running a TPG Generated Toolpath 17 Running a TPG Generated Toolpath Normally a filename O1999.txt is created by TPG and loaded into the CNC using the POLISH button on the GUI RUN page. The GUI MSD->File Names->Polish setting associates the O1999.txt file with the POLISH button on the GUI RUN page. Alternatively any file starting with O and ending with.txt can be created from TPG and activated using the GUI PROG->DIR(ectory) button. As long as the file is in C:\Cncfiles it will be displayed in the CNC Directory list. Figure 63: Selecting a program from a list Select a program to be executed and press F8 SELECT then move to the RUN page. The Bosch PNC Control program (taskbar icon ) has a mounted path /mnt1 pointing to the C:\Cncfiles directory. The Bosch PNC Control program is password protected. After entering the password the following screen is displayed. The /mnt1 points to /c/cncfiles (same as C:\Cncfiles). 6 6

68 Chapter: Running a TPG Generated Toolpath Figure 64: Checking the file directory mount point The GUI MSD->File Paths->Hard Disk setting and the Bosch PNC Control mount point above should be pointing to the same place, i.e. C:\Cncfiles. Once a program has been selected the GUI RUN page will look something like this. Figure 65: Preparing to run a selected program Check that the PROGRAM BUFFER is displaying the correct program. Turn the MANUAL/AUTO key on the CNC control panel to AUTO mode, shut the doors and hit the CYCLE START button to begin. 6 7

69 Chapter: Performing a Pre-Polish 18 Performing a Pre-Polish 1.33 Introduction In general optimum results are produced when using a soft compliant rubber bonnet. It is recommended to use a bonnet reinforced with glass fibre rather than the carbon fibre reinforced bonnet used for corrective polishing. Pre-Polishing differs from corrective polishing in that the tool is used pole down (i.e. with 0º Precess Angle) e.g.: Pole Down Tool Pre-Polishing Precessed Tool Corrective Polishing Precess Angle Figure 66: Pole Down (PrePolish) v s Precessed Tool (Corrective) Polishing Modes Another significant difference between the two styles is that Pre-Polishing is performed with the Part (C axis) and tool (H axis) rotating in the SAME direction. We term this synchronous polishing. By using a synchronized method the usual problems of polishing at centre are drastically diminished Check List A check list of the polishing procedure is available by pressing the F5 key from the SPIRAL menu of the TPG software i.e. Figure 67: PRE-POLISH CHECK LIST 6 8

70 Chapter: Performing a Pre-Polish 1.35 Correct Bonnet/Cloth Fitted For pre-polishing the bonnet should be as soft as possible. Bonnets reinforced with Glass Fibre rather than Carbon Fibre give good results. It is also possible to use un-reinforced bonnets with care. The bonnet should be prepared as normal with a suitable cloth applied and with a known diameter. A head pressure approximately ¼ of the polishing pressure should be applied. The effective bonnet/cloth radius should be determined according to section Condition Cloth The cloth should be clean and free from glaze. If there is sufficient depth of cloth available then the surface can be regenerated/conditioned using a diamond impregnated file or lapping tool Set Correct Tool Radius/Cloth Thickness Ensure that the correct parameters are entered in the TOOL/CNC PARAMETERS of the TPG software and are based on the effective tool radius/cloth thickness. Figure 68: Pre Polish Spot Size 1.38 Part Preparation The Part should be placed in the chuck and secured. The run-out of the part should be checked (see section 15) and if necessary adjusted to minimize any run-out. Please note that any run-out will cause a progressive non uniform polish to be generated. If possible a run-out of less than 5µm should be targeted Perform a ZTOP Operation See section

71 Chapter: Performing a Pre-Polish 1.40 Enter Correct Part Parameters in TPG Figure 69: PART PARAMETER Menu of TPG From the Part Parameters menu of the TPG software enter the appropriate settings for the part to be polished. The Workpiece diameter merely provides the user with useful information on tool overlap/underlap at the edge. It does not affect the toolpath generated. The correct Part Radius of curvature should be entered as appropriate, together with the desired base form (i.e. Plano, Convex, Concave, Aspheric or Freeform) 1.41 Setting the Polishing TPG Parameters From the Spiral Polish menu of the TPG software (shown overleaf), enter the desired polishing parameters. Figure 70: Spiral Polish Menu As a guide the following parameters should be entered: 7 0

72 Chapter: Performing a Pre-Polish Parameter Value Comments Spot Size 12mm (example) Enter the Spot Size of the polishing cloth used Precess Angle 0 degrees Pole down polishing should be used No. Precess Positions 1 Entering more than 1 will cause the total number of passes to increase by a factor of the number entered. It is recommended to use always use 1 as the value. The graphic display will advise how much of an overlap exists between the part and the edge of the tool. Polished Aperture (mm) 54 (example) If any of the tool overlaps the edge of the Workpiece, care must be taken to ensure that the polishing cloth will not be damaged. The edge of the glass must not be sharp if any overlap exists, if more than 30% of the spot size overlaps then it is recommended to have a supporting polishing ring. C Axis Speed (rpm) 800rpm (example) The choice of C axis speed will depend very much on the size of part being polished and the media being used. In general the larger the diameter of the part the slower the C axis speed. For part diameters of <60mm it is not unusual to specify a C axis speed of 1000rpm, whereas a part of 200mm diameter the C axis speed may be reduced to 250rpm. 7 1

73 Chapter: Performing a Pre-Polish If a subsequent corrective polish is not required then it is recommended that the Head Speed matches the C axis speed exactly. This will give the ideal condition for constant depth removal. e.g. Head (rpm) Speed 805rpm (example) If a Corrective polish is required or likely to be required then it is recommended that the H axis speed be increased by approximately 1% (or less) of the C axis speed (e.g. 805rpm). This will tend to produce a slight depression at centre and which is an easier form error to correct when using Precessions. e.g. Should the user feel it desirable to have a slightly raised area at centre then the H axis speed can be reduced slightly by a similar amount. e.g. X Data Spacing (mm) 0.25mm This value sets the drip feed rate to the CNC controller. The smaller the value the tighter the spiral polish and the better the resulting surface finish. It is not recommended to use a value of less than 0.25mm as this can cause very large data files. Experience has shown that a value of between 0.25mm and 0.5mm provides optimum results. This value sets the speed at Nominal A Axis Feed (mm/min) 5 Which the tool will move across the surface of the Workpiece. In general for pre-polishing it is better 7 2

74 Chapter: Performing a Pre-Polish Feed Slope v s Radius 0 This parameter can be used to increase or decrease the feed rate as a function of polishing radius (i.e. Increase or decrease feed as X increases). The normal setting is 0. Number Passes of xx Set a number which gives a total dwell time in-line with the depth of material to be removed. This is usually determined by experience. In general it is better to have a large number of passes at a higher feed rate than a low number of passes at a slow feed rate. Z Increment per pass 0 This option would allow the Z axis to increment by the stated amount on each pass. It is intended for use where large depths of material removal are required and where the spot size will diminish unless the tool is kept a constant distance for the part. If used the value should equate to:- Anticipated depth of removal Number of passes Total Time Dwell xx This value is determined by the product of the feed rate, number of runs, polishing aperture and spot size. Change any of the variables listed to increase or decrease the dwell time. Note that the time given is a close approximation to the total dwell time of the tool while polishing it is not the cycle time of the polishing operation which will be longer by several minutes to cater for machine clearance moves etc. Program Comment xxx Enter any text description and which will be entered in the header of the generated CNC file. Rotation Mode Synchronous Both the H axis and C axis will rotate in the same direction. Choosing Counter Rotation will give significantly non linear removal rates, and is designed only for use with a precessed tool. 7 3

75 Chapter: Performing a Pre-Polish Polish Mode Edge To Edge Edge to Edge polishing mode will provide the best results. In some circumstances and based on the part geometry it may not be possible to use this mode since a local normal of greater than 45degrees occurs. In such a circumstance select either Centre to Edge or Edge to Centre Mode. Use Flat Depth Unchecked Only use this function when using a tool at a precessed angle. CNC End M30 Only use M99 if the program is to form part of a group of sub-routine polishing programs. Lift Off Between Zones Unchecked Only select this option if problems are encountered at very slow feed rates with over-polishing at the edges of the aperture Non-Linear Corrections Table 7: TPG Parameters It is good practice to perform a non-linear correction probing routine on the first part of each batch. Performing this will show any significant errors in the Tooling or Part Parameters. If after performing the probing routine and reviewing of the graph the corrections are less than 30µm then the non-linear corrections can be turned off (see section 16) for how to perform non-linear corrections) Generate CNC file If satisfied with the need for non-linear corrections the CNC file can be generated by Pressing the {F2} key or selecting the {F2} generate CNC file command button. The user is prompted to enter the filename. The default value is O1999 and is the program called by the standard program launch CNC file loaded into memory. If the file is required to be stored or used as part of a sub-routine then rename the file as appropriate. Bosch have no filename limitations like Fanuc but Zeeko have used a similar naming convention for compatibility. The first letter of the CNC filename must be O followed by 4 numeric digits and the file extension is.txt Start CNC After switching on the slurry, start the CNC by pressing the START CYCLE button. 7 4

76 Chapter: Generating Influence Function(s) 19 Generating Influence Function(s) For the purposes of this exercise it is assumed that the influence function spots have already been produced on suitable samples and measured (in this case on a Form Talysurf). Several data file types are supported for creating influence function families. See the TPG and Precessions manuals for more information. If a DOS version of Form Talysurf software has been used it will be necessary to convert the data files to an ASCII format using the Conv_dep.exe utility supplied with the Form Talysurf. From Precessions MAIN menu select the option as shown: Figure 71: Part of Precessions MAIN Menu: FILE Tab - IMPORT Tab INFLUENCE FUNCTION Tab GENERATE INFLUENCE FUNCTION Tab Highlight the appropriate Form Talysurf file for example: Figure 72: PLEASE SELECT THE FILE CONTAINING THE DIF Menu Select the OPEN option. The data file will then be imported by Precessions. Please enter the nominal spot size applicable to the data, e.g.: 7 5

77 Chapter: Generating Influence Function(s) Figure 73: INFLUENCE FUNCTION Menu The value entered should be the same as that defined in the TPG software when generating the spot. i.e. Figure 74: INFLUENCE FUNCTION TPG Menu The actual spot size should not be entered, this will be calculated by Precessions. Please enter the total dwell time used to generate the spot. This is given by the dwell time per precess position x 4. (e.g. 60x4=240) Figure 75: INFLUENCE FUNCTION Menu The menu INFLUENCE FAMILY Menu will appear. Figure 76: INFLUENCE FAMILY Menu Select NO to have a single spot size influence function. For a family of influence functions select yes and repeat the procedure as given above for each spot size. When complete a graph will be shown of the imported influence function. E.g.: 7 6

78 Chapter: Generating Influence Function(s) Figure 77: INFLUENCE GENERATOR Menu The import routine will process the data to centre, denoise and shift the data as necessary. A dialog box which permits the creation of a suitable header file for the family will appear. e.g.: Figure 78: PRECESSIONS INFLUENCE FUNCTION HEADER PARAMETERS Menu Enter the appropriate comments that define exactly how the influence function(s) were generated. 7 7

79 Chapter: Corrective Polishing 20 Corrective Polishing 1.45 Importing an Influence Function Once an influence function or family of influence functions has been generated, they can be imported into Precessions. To import influence functions into Precessions select the menu option as shown: Figure 79: Part of Precession MAIN Menu: IMPORT Tab INFLUENCE FUNCTION INFLUENCE FUNCTION TAB Select the appropriate zki file, e.g.: Figure 80: SELECT FILE CONTAINING INFLUENCE FUNCTION DATA Menu Select the OPEN option. 7 8

80 Chapter: Corrective Polishing Figure 81: PRECESSIONS INFLUENCE FUNCTION FAMILY Menu A plot of the influence function(s) will then be display showing the actual spot sizes, removal rates etc. ACCEPT or REJECT the plot as appropriate. In some instances it may be desirable to re-scale the influence functions. If re-scaling is required, enter a new scaling factor as shown: Figure 82: PRECESSIONS INFLUENCE FUNCTION FAMILY Menu: SCALE FACTOR Field Re-scaling the influence function(s) is often used to provide a means of removing part of the error. By entering a value greater than 1 the total dwell times will be reduced. Typically a value of 1.5 will remove 80% of the error Importing an Error Profile from the Form Talysurf If a DOS version of Form Talysurf software has been used it will be necessary to convert the data files to an ASCII format using the Conv_dep.exe utility supplied with the Form Talysurf. If a Windows version of From Talysurf has been used, select the following option from Precessions mains menu: 7 9

81 Chapter: Corrective Polishing Figure 83: Part of Precessions MAIN Menu: FILE Tab IMPORT Tab ERROR PROFILE Tab Select the appropriate filter and file. Figure 84: SELECT FILE CONTAINING INFLUENCE FUNCTION DATA Menu Select the OPEN option, the profile is then displayed in the top left hand window of Precessions. Figure 85: Precessions MAIN Menu Often the data from a Form Talysurf will not be centred about the optic axis, it will also be noisy due to very high data densities, it will also have an arbitrary reference in X and Z. 8 0

82 Chapter: Corrective Polishing In order to improve the performance of the optimiser it is desirable to pre-process the data. The data can be manually manipulated if desired, however it is often better to start with the AUTOMATIC PRE-PROCESSING option and then if necessary perform manual refinements. To perform automatic pre-processing select the following option: Figure 86: Part of Precessions MAIN Menu: FILE Tab - AUTOMATIC PRE-PROCESSING Tab The system will then perform the following functions: Denoise Signal, Locate the point of best symmetry in the X-axis, Average & Fold the data about the point of symmetry, Shift the Z-axis to a zero reference at the point of intersection of the X=0 position (line of symmetry). Figure 87: PRE-PRCESSING; PLEASE WAIT Screen When complete, please ACCEPT the modified profile. The original and new profile will also be displayed. Figure 88: Modified Profile and CONFIRMATION Window 8 1

83 Chapter: Corrective Polishing If new profile has been accepted, a prompt will be given to extrapolate the signal. This may be required if a mask will be applied. ACCEPT or REJECT the new profile as appropriate. Figure 89: EXTRAOLATION Menu the User is Prompted With If YES is selected, then the user will be prompted to enter a value. Figure 90: EXTRAOLATION Menu the User Have to Enter the Extrapolation Value Enter a new value: The data will then be extrapolated to the new X value. The user will be prompted to ACCEPT the new profile. Figure 91: CONFIRMATION Menu ACCEPT OR REJECT the new profile as appropriate. On completion the finally modified profile will be updated in the top left hand window of Precessions. Figure 92: Precessions MAIN Menu and Modified Profile 8 2

84 Chapter: Corrective Polishing If necessary this modified profile can be exported as a MOD file. useful if the same error profile is required for further optimisations. This may be This can be done by selecting the export error profile option from the PRE-PROCESSING menu. e.g.: Figure 93: Precessions MAIN Menu: FILE Tab ERROR PROFILE Tab A SAVE AS dialog box will appear allowing the processed error profile to be saved as a Form Talysurf mod file. Safe error profile as a Form Talysurf mod file Designing the Required Profile It is necessary to define the required profile in order to perform an optimisation. It is preferable to define the required profile after importing the error or actual profile. The reason for this is that if an error or actual profile already exists then the software will automatically set the start & end points of the design profile in addition to matching the spacing resolution the same as the error/actual profile data. It is important to know the measurement/analysis basis of the data used for the error or actual profile. The type of metrology device used may vary and the data obtained may present the data in different co-ordinate system. For example a Form Talysurf will present data in either a surface co-ordinate system (S-Z) or axis co-ordinate (X-Z) system depending on the choice of form fit. s (0,0) z Base Form (e.g. LS Arc) Error Profile Figure 94: Surface Co-Ordinate System 8 3

85 Chapter: Corrective Polishing (0,0) x z Base Form (e.g. LS Arc) Actual Profile Figure 95: Axis Co-Ordinate System Typically the type of co-ordinate system used will be as described in following table: Instrument Reference Co-Ordinate System Form Talysurf LS Line Surface Co-Ordinates LS Arc Surface Co-Ordinates Aspheric Axis Co-Ordinates Datum Axis Co-Ordinates Zygo All Axis Co-Ordinates Wyko All Axis Co-Ordinates Loh T II Axis Co-Ordinates Table 8: Reference and Co-Ordinate Systems of Different Instruments In Precessions the design of the required profile will depend on the co-ordinate system used. Where the co-ordinate system is axis then the design profile should be defined as per the actual shape of the part (e.g. flat, convex, concave, or conic ). If the co-ordinate system used is surface then the designed profile should always be specified as flat. To design the required profile select the menu options as shown: 8 4

86 Chapter: Corrective Polishing Figure 96: Part of Precessions MAIN Menu: FILE Tab DESIGN Tab REQUIRED PROFILE Tab Figure 97: Precessions PLOYNOMINAL EDITOR : PARAXIAL REGION Tab If CONVEX or CONCAVE is selected then the option is also available to enter polynomial coefficients to the conic equation. Figure 98: Precessions PLOYNOMINAL EDITOR : BASE RADIUS Field To generate a Schmidt plate it is necessary to still define the base form as CONVEX or CONCAVE, however the BASE RADIUS value can be specified as INF (i.e. infinity). e.g. 8 5

87 Chapter: Corrective Polishing Figure 99: Precessions Polynomial Editor Once the required profile has been designed the user will be promoted to accept the new profile and the resulting profile is added to the bottom left window of Precessions e.g. Figure 19.3g: Precessions MAIN Menu: Actual and Desired Profile 1.48 Performing an Optimisation An optimisation can only be performed when the following data has been designed or imported: Error profile or actual profile, Design profile or design error, Influence function. Depending on the data imported or designed Precessions will calculate the missing set of data. For example if an error is designed and the actual is imported then the design profile will be derived. If the actual and design profile have been imported/designed then the error profile will be derived. If the required data is not present then the option to perform an optimisation is inhibited. Typically an optimisation will include the setting of optimisation parameters and constraints. 8 6

88 Chapter: Corrective Polishing Setting Optimisation Parameters Figure 100: OPTIMISATION SETTINGS Screen OPTIMISATION Menu: OPTIONS Tab - MAX ITERATIONS Tab Typically 20 iterations will be sufficient to generate a suitable optimisation OPTIMISATION Menu: OPTIONS Tab - PROFILE/SLOPE/TIME WEIGHT Fields These values set the relative importance of either profile (P-V), slope or time to the optimisation. Typically a setting of 1,0,0 is used, however if some loss of form error control can be tolerated, the slope weighting factor can be increased to provide a smoother result. (e.g. 1, 0.3, 0) OPTIMISATION Menu: OPTIONS Tab - MAX TOOL SIZE Field This will normally default to the size of the largest spot in the family of influence functions. If desired this can be capped a any value less than the maximum spot size. Alternatively the spot (tool) size can be constrained between an upper and lower limit by entering a min-max value and where the values are separated by a space (e.g ). The majority of optimisations are performed with a tight control of spot size using a single curve in the influence function family. If for example a nominal 6mm influence function curve has been imported then the values entered into this field would typically be

89 Chapter: Corrective Polishing OPTIMISATION Menu: OPTIONS Tab - MAX DWELL TIME Field The maximum dwell time should be set high enough that it will not cause too tight a constraint. The value will typically be greater for larger diameter parts and/or where the errors are large. It may be necessary to experiment with suitable values. Figure 101: Precessions MAIN Menu: Example for Max Dwell Time Set to Short (100secs) In the example shown, the max dwell time is set too short (100secs) as can be seen by the dwell time figures which have all reached the maximum value at radii greater than 5mm. The residual profile error has been adversely affected by such a constraint. Figure 102: Precessions MAIN Menu: Example for Max Dwell Time Set Suitably By setting the max dwell time to 10,000 seconds the resultant profile is significantly better e.g. Even though the max dwell time is set to 10,000 the actual maximum value used is only 350secs. As a general rule it is often best to set the value much higher than that necessary such that it does not restrict the optimiser. The residual profile is now much better but still suffers from ripple. The reason for this is that a mask has not been sued. See later for more details on overcoming this phenomenon. 8 8

90 Chapter: Corrective Polishing OPTIMISATION Menu: OPTIONS Tab - PROFILE RESOLUTION Field This value can normally be set to 0.1. The greater the value, the faster the optimization, but the poorer the result and visa versa OPTIMISATION Menu: OPTIONS Tab - INITIAL ZONE SPACING Field The zone spacing is a major factor is determining how quickly the optimiser will perform. The greater the spacing the quicker the result, however the result will suffer from cusping if set too far apart. The time is often a square-law function, therefore the time to achieve a result with 0.5mm spacing will be 4 time greater than that at 1mm spacing (approx.). Experience has shown that 1mm spacing will give a reasonable result (on optics of 50mm diameter). The result can then be interpolated to a finer spacing before exporting to the ToolPath Generator (TPG) and to avoid cusping on the part OPTIMISATION Menu: OPTIONS Tab - CONSTANT ZONE SPACING Check Box If checked the optimiser will use fixed zone spacing as set in the INITIAL ZONE SPACING value. If this option is unchecked then the optimiser will be allowed to vary the spacing on each successive pass to achieve the optimum result. If the results are to be interpolated (to a closer spacing) then it is necessary to check this option OPTIMISATION Menu: OPTIONS Tab - TOOL/PIECE OVERLAP Field See reference section of Precessions Handbook OPTIMISATION Menu: OPTIONS Tab - TOOLSIZE CHANGE Field See reference section of Precessions Handbook OPTIMISATION Menu: OPTIONS Tab - DWELL TIME BIAS Field See reference section of Precessions Handbook OPTIMISATION Menu: OPTIONS Tab - ZONE SIZE BIAS Field See reference section of Precessions Handbook OPTIMISATION Menu: OPTIONS Tab - TOOL SIZE BIAS Field See reference section of Precessions Handbook 1 In a future revision of Precessions, this restriction may not apply. 8 9

91 Chapter: Corrective Polishing OPTIMISATION Menu: OPTIONS Tab - INITIAL DWELL Field This value should normally be set to RAMP. This will cause the optimiser to start with dwell times that are based on a πxd factor OPTIMISATION Menu: OPTIONS Tab - INITIAL TOOLS Field This value should be set to MIDDLING. This will start the tool/spot size to the mid range. If a range of is allowed the optimiser will try and use 6.0mm. This is the preferred choice when using a single Influence Function OPTIMISATION Menu: OPTIONS Tab - USE IAE INSTEAD ISE Check Box See reference section of Precessions Handbook. The preferred setting is UNCHECKED OPTIMISATION Menu: OPTIONS Tab - IGNORE DC OFFSET Check Box See reference section of Precessions Handbook. UNCHECKED Setting Constraints It is possible to set 2 types of constraint on the optimiser, these are: SPOT SIZE, MASK. Either or both constraints can be applied. The preferred setting is When a spot size constraint is applied the optimiser will perform 25% of the allowed iterations without any constraint. (e.g. if 40 iterations are allowed, then the first 4 will be performed without constraint). On subsequent iterations the constraints(s) will be applied. It may appear that the predicted results get worse on first application of the constraints Setting the SPOT SIZE Constraint Select the menu option as shown as below. 9 0

92 Chapter: Corrective Polishing Figure 103: Part of Precessions MAIN Menu: OPTIMISATION Tab CONSTRAINTS Tab SPOTSIZE Tab 2 lines will appear at the top/bottom of the top left hand window. Each line will have 4 drag handle anchors. Performing a click-drag mouse move on any of the anchors will allow its position to be changed. Any or all of the anchors can be moved to restrict the choice of spot sizes at any given radial position. Where only a single influence function has been loaded and the max-min spot size constraint has been applied this method of constraint should not be used. Figure 104: Precessions MAIN Menu: Restricting the Spot Size Setting a MASK Constraint Select the menu option as shown below: 9 1

93 Chapter: Corrective Polishing Figure 105: Part of Precessions MAIN Menu: OPTIMISATION Tab CONSTRAINTS Tab MASK Tab 2 vertical lines will appear on the left/right of the top left hand window. Performing a click-drag mouse move on either line will allow its position to be moved. The mask may be single sided or double sided. Figure 106: Precessions MAIN Menu: Setting a Mask Constraint When a mask is applied the optimiser will ignore the effects outside of the mask and try to minimise the error inside the mask.. It may choose long dwell times and/or spot sizes outside the mask to have an effect inside the mask. Please note that the optimiser will still generate zones outside the mask. Typically a mask will be used at the required aperture of the optic. This is essential where the error is large outside of the required aperture (usually required when a polishing ring is not used and the tool starts/stops on the optic). Using a mask constraint applied at the required aperture will often minimise the degree of cusping in the predicted residual profile, e.g. 9 2

94 Chapter: Corrective Polishing Figure 107: Optimisation without Mask Applied Figure 108: Optimisation with Mask Applied at Required Aperture 1.49 Interpolating an Optimisation When a suitable result has been obtained it can either be exported as-is or it can be interpolated and/or manipulated before exporting to the ToolPath Generator. Typically it will be necessary to interpolate the result to allow the data to be feed to the CNC with a sufficiently fine resolution to avoid cusping of the surface when polished. Typically data is feed to the CNC at a spatial resolution on 0.25mm. From the results window select the following menu option to perform an interpolation: The user can select either a linear INTERPOLATE (linear) or a INTERPOLATE (NURBS) method. 9 3

95 Chapter: Corrective Polishing Figure 109: Part of Precessions RESULTS Menu: FILE Tab DWELL TIMES EDITOR Tab INTERPOLATE (NURBS) Tab On selection of either interpolation mode the user will be promoted to enter a new spacing value. On entry of this value a new predicted residual profile will be calculated using the new interpolated dwell times/positions, e.g. Some degradation of predicted result will often occur. The user must balance the needs of accuracy v s optimisation time. Figure 110: Precessions RESULTS Menu: Predicted Residual Profile, Calculated Using the New Interpolated Dwell Times/Position 1.50 Automatic Post Processing of Optimisation Result Often it will be considered desirable to slightly modify the optimisation results in light of known constraints of the machine/process. e.g. Unrealisable short dwell times, Unnecessary tool position outside of the zone to be polished, Prevention of dwell time cycling (if the error to be corrected is large then the optimiser will often cycle dwell times from high to low) e.g.: 9 4

96 Chapter: Corrective Polishing Low High High Low Minimal Dwell Times Figure 111: Dwell Time Cycling Problem An option exists to automatically process the data and which on selection will: Drop zero dwell time zones (except anchor points), Drop zones outside the mask area + half of the actual spot size. Automatic post processing can be performed by selecting the option as shown in the following: Figure 112: Part of Precessions RESULTS Menu: FILE Tab DWELL TIMES EDITOR Tab AUTOMATIC PROCESSING Tab The result will be as follows: Figure 113: Automatic Processed Data 9 5

97 Chapter: Corrective Polishing Several of the red zones close to the centre have been removed Manual Manipulation of Dwell Times In some instances the user may choose to modify the dwell time chosen by the optimiser. This may be the case where due to large form errors the optimiser has cycled the dwell times e.g.: High High Low Low Figure 114: Dwell Time Cycling Problem By using the moderate dwell time function the user has manually adjust the dwell times to smooth the output. In general it is preferable to maintain the overall dwell time chosen by Precessions. The dwell times should be re-distributed to smooth out the curve. Each time a dwell time is changed a new predicted profile will be given. There are 2 methods of adjusting the dwell times, these being: Modify Dwell Time (Visually) On selection of this option position the cross hair cursor on the point to be modified and click the mouse button. Reposition the cross hair cursor at the new dwell time position. The radial position will not be changed Modify Dwell Time (Manually) On selection of this option position the cross hair cursor on the point to be modified and click the mouse button. The user will then be prompted to enter a new dwell time value. It is often quicker to modify dwell times before interpolation since there are fewer points to modify. The examples below show before dwell time moderation, after dwell time moderation and after interpolation. 9 6

98 Chapter: Corrective Polishing Figure 115: Examples for Before Dwell Time Moderation, After Dwell Time Moderation and After Interpolation 1.52 Exporting to the ToolPath Generator (TPG) When all an acceptable result has been achieved it is necessary to export the data to the TPG software. This can be via floppy disc or network connection (if available). In order to export the file, select the MENU option as shown from the results window: The user will the presented with a SAVE AS dialog box. The user can then enter a suitable filename and choose an appropriate folder for the data. Figure 116: Exporting to TPG 9 7

99 Chapter: Corrective Polishing 1.53 Designing an Error Profile If an Actual Profile has been imported then the error profile can be derived by importing or designing the required profile. Precessions will then calculate the difference as an error profile. It is also possible to derive the required profile by importing the actual profile and designing an error profile. This is often useful if a constant depth of removal is required. Firstly import the Actual profile, then from the FILE-DESIGN menu select the ERROR PROFILE option (see figure). Figure 117: Precessions TPG Menu: FILE Tab DESIGN Tab ERROR PROFILE Tab On selection of this option the user will be prompted to enter a value that represents the depth of material to be removed. Enter a value (in millimetres) that represents the depth of the material to be removed e.g. 1e-3 or to represent 1µm. Figure 118:Insert the Depth of the Material to be Removed Select OK On selecting the OK option, the MAIN menu will be updated to show the Actual profile and the derived Design profile e.g. (shown below). 9 8

100 Chapter: Corrective Polishing Figure 119: Precessions MAIN Menu: Actual and Design Profile An optimisation can now be performed in the normal manner (e.g. after importing an influence function and setting the required optimisation parameters). 9 9

101 Chapter: Setting Crash Detection Sensitivity 21 Setting Crash Detection Sensitivity The GUI MSD Crash Detect page contains the settings for controlling the crash detection in the Bosch PLC. Figure 120: GUI 'MSD' Crash Detect Page The Bonnet size buttons select the appropriate Step limit value. The Step limit value is the change in load cell transducer value over a time interval set with the Step time set value. To desensitise the crash trip level either reduce the Step limit or increase the Step time set value. The suggested increment is 100units for the Step limit. Crash detection can also be disabled by un-ticking the Crash detect enabled checkbox although this is not advised. Figure 121: GUI 'MSD' Analog Page The load cell gain is controlled by Analog Input 2 Gain. The value should nominally be set to The Analog Input 2 Offset value is calculated automatically when the NULL button is pressed to give a displayed load cell value of zero

102 Chapter: Axis Over-Travel 22 Axis Over-Travel Under normal conditions the axes are protected from over travel by software limits. On reaching a software limit the axis will decelerate to a stop and an alarm message will be displayed on the CRT. To recover from a software limit alarm manually jog the axis in the opposite direction. It will then be necessary to clear the alarm by pressing the RESET push-button. The CNC remembers the position of the axis even when switched off; hence soft limit protection is active at all times. Should an axis be moved by hand with the CNC off (e.g. during maintenance), the axis will be out of sync from the CNC, and the soft limits will be incorrectly applied. To bypass the software limits press the P and CAN keys simultaneously and press CONTROL ON. Keep the P and CAN keys pressed until the EMG message appears.) 1 0 1

103 Chapter: CNC Memory 23 CNC Memory 1.54 Loading Files from CNC Memory See note below Loading a File into CNC Memory See note below Deleting a File from CNC Memory See note below. On Zeeko machines using a Bosch PNC controller the Zeeko GUI no longer moves files between the CNC memory and the hard disk of the PC. The Bosch PNC Control program (taskbar icon ) has a mount directory /mnt1 that points to C:\Cncfiles directory on the hard disk. The Zeeko GUI PROG->DIR page displays files from this directory. Files can still be deleted with the Zeeko GUI PROG page but these files will be deleted from the C:\Cncfiles directory. Figure 122: Bosch PNC Control Program 1 0 2

104 Chapter: Manual Setting of G54 Z OFFSET 24 Manual Setting of G54 Z OFFSET From the Zeeko GUI MAIN menu select the SDF Edit option. Press the OFST button on the CNC control keyboard. In some instances it may be necessary to press this more than once depending on the last offsets screen viewed. Select the WORK option. Figure 123: SDF Screen Showing G54 Offset Values Use the cursor keys to navigate to the G54 Z OFFSET location and use the keyboard to enter the new value followed by ENTER (e.g and which is typically a clearance position)