Easy Machining Center Setup

Transcription

1 White Paper Document No. MWA-072-EN_01_1404 April 2014 Easy Machining Center Setup Using FANUC s Direct Input of Workpiece Origin Setting Measured and Tool Length Measurement features to easily establish workpiece coordinate system and tool length geometry offset values.

2 1 Introduction Choosing a Tool Length Measurement Method Additional Tools Required Measuring Workpiece Coordinate System Offset Values How Does the Direct Input of Workpiece Origin Setting Measured Feature Work? Measuring X and Y Axes Workpiece Coordinate Offset Values Procedure to Set the X and Y Axes Workpiece Coordinate System Offset Values Measuring Z-axis Workpiece Coordinate Offset Procedure to Set the Z-axis Workpiece Coordinate System Offset Value Measuring Tool Length Geometry Offset Values Tool Length Measurement Methods How Does the Tool Length Measurement Feature Work? Using the Reference Tool Method Using the Touch-off Method Reference Tool Method Procedure to Measure Tool Length Geometry Offset Values with a Reference Tool Touch-off Method Procedure for Measuring Tool Length Geometry Offsets using the Touch-off Method Summary 18 Document # MWA-072-EN_01_ Page 2 of 20

3 1 Introduction Before running a new job on a CNC machining center or mill there are several setup tasks that the operator must complete. Steps include: Securing the workpiece in a vice, fixture or other workholding device Loading any new tooling Set the workpiece coordinate system offset values in the CNC Set the tool geometry offset values in the CNC Using workpiece coordinate system and tool geometry offsets simplifies part programming and by allowing the programmer to ignore the physical machine and tooling characteristics during program creation. They also enhance scheduling flexibility, within limits, because programs using these features will run on a wide range of machine and tooling configurations. Workpiece coordinate system offsets resolve the difference between the program zero assumed in the part program and the actual machine zero. Tool geometry offset resolves the difference between the zero length and diameter tool assumed when creating the part program and the actual tool lengths and diameters used at production time. Establishing the values for the workpiece coordinate system and tool geometry offsets at setup time is confusing to some machine operators and it is a source of data entry errors. FANUC s Direct Input of Workpiece Origin Setting Measured and Tool Length Measurement features simplifies and error-proofs setting offset values. Both features are standard in the FANUC Series 0i-MD machining center CNC and available as an option for the FANUC Series 30i/31i/32i. They are also available as standard or optional features on many other FANUC CNCs. 1.1 Choosing a Tool Length Measurement Method Two methods are commonly used to establish tool length offset values. The choice also impacts the way the workpiece coordinate offset Z-axis value is established. Reference Tool this method as the name implies uses a reference tool to establish the tool length offset values. The reference tool has tool length offset value of zero and all the other tools have a length relative to the reference tool. If the reference tool method is chosen, the reference tool is also used to establish the Z-axis workpiece coordinate system offset value. The reference tool method is preferred by production shops or progressive job shops that minimized setup time by using standardized tool setups. Touch-off this method measures every tool used in the current program relative to a reference surface on the part, usually the top of the workpiece blank. The Z-axis workpiece coordinate system value is set to zero. This method is commonly used in smaller job shops and toolrooms where setup time is less important and the machine s tool changer capacity does not allow for standard tool setups. Document # MWA-072-EN_01_ Page 3 of 20

4 At first glance it may appear that the touch-off method eliminates the need to establish the Z-axis workpiece coordinate system value and is therefore more efficient and preferred. In practice the reference tool method eliminates the need to re-measure any previously measured tool. By standardizing as many tools as possible in the tool changer, the reference tool method limits job setup to measuring the Z-axis workpiece coordinate system value and the length of any new tools. 1.2 Additional Tools Required The measurement process requires a few inexpensive tools: Workpiece coordinate offset measurement - a low cost edge finder (~$20) can be used to establish the X and Y axes workpiece coordinate system offset values. A thin piece of paper can be used to measure the Z-axis workpiece coordinate system value. Tool length geometry offset measurement - an inexpensive (~$100-$200) electronic or dial offset gage provides quick and efficient measurement when using the reference tool method. A thin piece of paper is all that is needed for the touch-off method. Tool geometry diameter data can be found in the tooling catalog or measured with a suitable caliper or micrometer. Since tool diameter measurement is a very common procedure, we will not discuss it further here. 2 Measuring Workpiece Coordinate System Offset Values Using a workpiece coordinate system in the part program requires the workpiece coordinate system offset to be specified at setup time. In these procedures, the program zero points are assumed to be the bottom left of the part in X and Y and the top of the part in Z, since this is common Document # MWA-072-EN_01_ Page 4 of 20

5 2.1 How Does the Direct Input of Workpiece Origin Setting Measured Feature Work? Z Edge Finder X X Workpiece Ø0.200 Vice Position of X-axis after detecting the left hand edge of a part with an edge finder The basic concept of using an edge finder on a CNC machining center and a conventional mill with a digital readout (DRO) is the same. In the illustration above, there is a inch diameter edge finder that has been positioned so it is just in contact with the left edge of the workpiece. The example screen to the right shows the CNC position registers after a diameter edge finder just makes contact with left-hand edge of a part. The CNC displays X inches in both the absolution (program) position and the machine position registers. What we are trying to do is set lefthand edge of the workpiece as the program zero in the X-axis. If the edge finder had no diameter, touching the part on the left would mean that we would want to set the current axis position to zero in the workpiece coordinate system. Document # MWA-072-EN_01_ Page 5 of 20

6 However, the edge finder has a diameter inch and the actual position in the desired workpiece coordinate system is half the diameter of the edge finder in the negative direction. That is the current position is actually (0.2000/2.0=0.1000) in the negative direction or the axis is at the position X This makes sense, if current position was X , programming an absolute move to X0.0 would move the X-axis 0.1-inch in the positive direction, placing the center of the edge finder directly over the left-most edge of the part. So we want tell the CNC to set the current absolute (program) position for the X axis to X (half the diameter of the edge finder in the negative direction). That is exactly what the Direct Input of Workpiece Origin Offset Value Measured feature does. The operator positions an axis to a known location in the workpiece coordinate system using the edge finder, in this case inch in X. The operator then enters the letter address of the axis being measured followed by the desired position in the coordinates of the workpiece coordinate system X-0.1 in this example. When the operator presses the [MEASUR] soft key, the CNC then calculates and sets the value of the workpiece coordinate system offset required that makes the current absolute (program) position the value specified by the operator. In the middleright CNC screen you can see the CNC has calculated an X-axis workpiece coordinate system offset of In the bottom-right CNC screen you can see that the absolute (program) position is now X , the value set by the operator. Document # MWA-072-EN_01_ Page 6 of 20

7 The Direct Input of Workpiece Origin Setting Value Measured feature simplifies and error-proofs workpiece coordinate system offset data entry. Without this feature, the operators must read the axis position, add the diameter of the edge finder, select the appropriate workpiece coordinate offset field (X/Y/Z), enter the resultant value in the key input buffer and then press the INPUT key on the MDI panel. Though no high mathematics is involved, the procedure does provide multiple opportunities for errors. The same basic concept is used when measuring the Z-axis coordinate system offset. However, instead of allowing for half the diameter of the edge finder, we are allow for the thickness of the paper shim used. If the top surface is not qualified, we can also allow for the amount to be machine off the surface of the part to the part zero in the Z-axis. In this case the Z-axis is positioned a paper thickness above the part. The actual position of the tip of the tool is inch in the positive direction from the desired program zero point. If we are to take off inch from the top surface, the zero point is plus inches from the current Z-axis position. If the machine position in the Z-axis is Z (see illustration below) when the reference tool is in contact with the paper and the operator enter Z0.054 into the key input buffer on the CNC Workpiece Coordinate System offset page and presses the [MEASURE] soft key, the Z-axis workpiece coordinate system offset will be set to Z and the absolute (program) position becomes Z Program an absolute move of Z0 will move the Z-axis inches in the negative direction to the surface of the part. Reference Tool (spindle nose) Z X Paper Z Workpiece Vice Position of Z-axis after detecting the top surface of a part with a thin paper shim Document # MWA-072-EN_01_ Page 7 of 20

8 2.2 Measuring X and Y Axes Workpiece Coordinate Offset Values Finding the position of the side of a part with an edge finder is considered such a basic procedure that the device manufacturers rarely provide any instructions with their products. Using an edge finder with a CNC is very similar to using an edge finder with a manual machine with a digital readout (DRO) except we have the more capable CNC to make the process a little easier. Edge finders come in both mechanical and electronic versions: Mechanical Edge Finder has a main body that mounts in a tool holder, collet or chuck. The measuring end of the edge finder is attached to its body with a strong spring. When installed in the spindle, running at around 1,000 RPM, the measuring end typically wobbles some operators flick the end to kick it off-center and force it to wobble. When the edge finder is very close to the edge of the part, the body and the measurement end stabilize and line up concentrically. Moving just a bit closer to the edge makes the measurement head kick off-center decisively, indicating that the edge has been detected. While it is prudent to look along the edge being detected while jogging the edge finder into position, it is important to look perpendicular to the edge to detect the kick. Electronic Edge Finder works like a low cost trigger probe. Electronic edge finders have lights, audible alarms or both to signal when the measurement end comes in contact with the workpiece edge. The electronic edge finder may have a ball ended stylus, similar to a trigger probe. Electronic edge finders are used with the spindle stopped. Aside from the kick of the mechanical edge finder versus the light or audible alarm of the electronic edge finder, the procedure to find an edge position is very similar. The position detected by the edge finder will be off by half the diameter of the sensor tip. It is important to know the diameter of the sensor, because it must be considered when entering the offset data into the CNC Procedure to Set the X and Y Axes Workpiece Coordinate System Offset Values 1. Make sure that the workpiece coordinate system offset used in the part program is active typically the G54 for single part setups. Check the modal G-codes on the position page. If it is not active, activate it using manual data input (MDI) mode. 2. Inspect the workpiece on the edges to be measured and make sure there are no burrs or other artifacts that might produce a false edge detection. If necessary, dress the edge with as hone or file. 3. Mount the part in the workholding. Document # MWA-072-EN_01_ Page 8 of 20

9 4. Place the edge finder in a tool holder and place it in the spindle, either manually or using the automatic tool changer. 5. If using a mechanical edge finder, start the spindle at 1,000 RPM or the speed the manufacturer recommends. You can program the spindle speed in MDI and press cycle start. Start and stop the spindle with manual operator buttons or use MDI to execute the spindle start and stop M-codes (M03/M05). For an electronic edge finder, skip this step. 6. Jog the X, Y and Z axes so they are about an inch off the edge to be measured. You can use continuous jog mode or an electronic handwheel (also called an MPG or manual pulse generator) with a suitable increment setting. 7. Move to a lower jog speed or to smaller increment setting when using an electronic handwheel. 8. Move the edge finder in the Z-axis only until the measurement end is just below the top surface of the workpiece. It is important that only the tip of the mechanical edge finder or the stylus tip of the electronic edge finder is below the top surface of the workpiece. Move the axis slowly to ensure there is no collision; otherwise the instrument may get damaged. 9. Switch to incremental jog mode or continue to use an electronic handwheel. In either case, switch to the smallest increment available. 10. Slowly, move the edge finder towards the edge of the part until it is almost touching. 11. This step is slightly different depending on whether mechanical edge finder or an electronic edge finder is being used a. If using a mechanical device, very slowly move the edge finder towards the edge until the upper and lower parts align and stabilize. Move your observation point so that you can look at the edge finder in a direction perpendicular to the edge being measured, looking across the part if possible. Jog one increment at a time until the edge finder kicks. Back off a couple of increments and then back towards the part until it kicks again to ensure the position sensed is repeatable. b. If using an electronic device, very slowly move the edge finder towards the edge until the light or audible sound is signaled. Back off a couple of increments and then jog back to the part at one increment at a time until the edge finder signals again to ensure the position sensed is repeatable. Document # MWA-072-EN_01_ Page 9 of 20

10 12. Press the function button on the CNC MDI panel. 13. Press the [WORK] soft key to display the workpiece coordinate system offsets page. 14. Press the [OPRT] operations soft key to display the [MEASUR] soft key. 15. If necessary, press the key on the MDI panel until the workpiece coordinate system offset used in the part program is displayed typically the G54 offset. 16. Use the,, and cursor keys to highlight the X-axis field of the offset to be updated typically the G54 offset. Note you can select the X-axis field even if you are measuring the Y-axis because the next step sets the axis to be actually updated). 17. Enter the X letter address (or Y letter address) followed by the current axis position in the coordinates of the workpiece coordinate system. For example, if the edge finder has a diameter of inches and is in the negative direction relative to the desired workpiece coordinate zero, enter X-.1 (or Y-.1). 18. Press the [MEASUR] soft key the appropriate offset value is automatically set in the workpiece coordinate system offset table. The procedure above is repeated once for the X-axis and once for the Y-axis. See a video demonstrating these steps, here. 2.3 Measuring Z-axis Workpiece Coordinate Offset If you are using the reference tool method of setting tool length geometry offsets (see section 3), it is time to establish the Z-axis workpiece coordinate system offset using the reference tool, the top of the part and a thin piece of paper. The reference tool may be the spindle nose, the longest tool or the most common tool. The spindle must be stopped for this operation. If you plan to use the touch-off method of setting tool length geometry offsets, the Z-axis workpiece coordinate system offset value must be set to zero (cursor down to the Z field in the offsets, enter zero in the key input buffer and press the INPUT key on the MDI panel). Skip the procedure below Procedure to Set the Z-axis Workpiece Coordinate System Offset Value 1. Make sure that the workpiece coordinate system offset used in the part program is active. Check the modal G-codes on the position page. If it is not active, activate it using MDI mode. 2. Jog the X, Y and Z axis so the reference tool is about an inch above the top surface of the part. You can use continuous jog mode or an electronic handwheel with a suitable increment setting. 3. Switch to incremental jog mode or continue to use the electronic handwheel. In either case, switch to its smallest increment available. 4. Very slowly move the Z-axis until it is almost touching the part, leaving a gap of a little over a paper thickness. Document # MWA-072-EN_01_ Page 10 of 20

11 5. Press the function button on the CNC MDI panel. 6. Press the [WORK] soft key to display the workpiece coordinate system offsets page. 7. In necessary, press the key on the MDI panel until the workpiece coordinate system offset used in the part program is displayed typically the G54 offset. 8. Press the,, and cursor keys to highlight the X-axis field of the offset to be updated typically the G54 offset. 9. Take a thin piece of paper and test if it can be inserted between the reference tool (the spindle nose in the image) and the top surface of the machine. If the paper moves easily, jog the axis down one increment and re-test the fit. 10. Repeat step 8 until there is a slight mechanical resistance when inserting the paper between the part and reference tool. The reference tool is now one paper thickness above the top surface of the part. 11. This next step depends on whether the top of the part is a finished machined surface or not. Start by entering the Z letter address in the key input buffer. Next: a. For a previously qualified machined surface, enter the thickness of the paper (.004 for example) in the key input buffer after the Z letter address. b. For an un-machine surface, determine the amount of material to be removed during facing (0.050 for example) and enter that value in the key input buffer using the CNC MDI keyboard. Note we are ignoring the thickness of the paper as it is insignificant in this case. If you want to be precise, add the paper thickness to the value of the material to be removed (.054 for example) and enter that value. 12. Press the [MEASUR] soft key the appropriate offset value is set in the Z-axis workpiece coordinate system offset table value. See a video demonstrating these steps, here. Document # MWA-072-EN_01_ Page 11 of 20

12 3 Measuring Tool Length Geometry Offset Values 3.1 Tool Length Measurement Methods As was stated in the introduction, there are two methods commonly used to establish tool length offset values. Reference Tool this method uses a reference tool to establish the tool length offset values. The reference tool has tool length offset value of zero and all the other tools have a length relative to the reference tool. The reference tool method is preferred by production shops or progressive job shops that minimized setup time by using standardized tool setups. Reference Tool Method Reference Tool (spindle nose) Z-axis Relative Zero Offset Gauge Vice Z Tool Relative Length X Touch-off this method measures every tool used in the current program relative to a reference surface on the part, usually the top of the workpiece blank. This method is commonly used in smaller job shops and toolrooms where setup time is less important and the machine s tool changer capacity does not allow for standard tool setups. Touch-off Method Paper Tool Z Z (relative position) X Workpiece Vice Document # MWA-072-EN_01_ Page 12 of 20

13 3.2 How Does the Tool Length Measurement Feature Work? The Tool Length Measurement simply copies the relative position register of the axis selected to the tool length offset field selected. Using it for tool length measurement requires that the relative position be zeroed at the appropriate location for the method being used Using the Reference Tool Method When the reference tool method is used to measure tool lengths, the trick is to establish the Z-axis relative position zero when reference tool is at the tool measurement position. Though we provide more detail in the procedure that follows, there are four primary steps in the process: 1. Move the reference tool to a reference position. This is when the reference tool is in contact with the offset gauge. 2. Reset the Z-axis relative position to zero. 3. Install the tool to be measured in the spindle and move the tip of the tool to the same reference position. The Z-axis relative position register should now display the relative length of the tool. 4. Select the tool offset number and the geometry length offset field to be updated and enter Z in the key input buffer and press the [INP. C] soft key to copy the Z-axis relative position to the tool offset field Using the Touch-off Method When the touch-off method is used, the Z-axis relative position zero should be the same as the machine position zero, which is automatically established when the CNC is turned on. Moving each tool used to the workpiece surface and coping the Z-axis relative position to the appropriate offset compensates for the tool length and the difference between the machine zero and the program zero at the same time. 1. Install the tool to be measured in the spindle and move the tip of the tool to the surface of the workpiece. The Z-axis relative position register should now display the relative distance from the home position to the tip of the tool. 2. Select the tool offset number and the geometry length offset field to be updated and enter Z in the key input buffer and press the [INP. C] soft key to copy the Z-axis relative position to the tool offset field. Document # MWA-072-EN_01_ Page 13 of 20

14 3.3 Reference Tool Method The reference tool method is the most efficient way to establish tool geometry length offsets, when a standardize tool load is possible. For each job setup, only the lengths of new tools need to be measured. Note: if you routinely replace every tool in the tool changer for every job; consider using the touch-off method that is discussed later in section 3. There are several common variations of the reference tool method and they all work well the key difference is the sign and the values stored in the tool geometry table: Common tool - this method uses a tool that is always in the tool changer as the reference tool. This makes sense because without the previously used reference tool to establish the Z-axis workpiece coordinate system offset value, all the tools used in the job would have to be measured again using a new reference tool defeating the objective. Some tools may be longer than the reference tool and they have a positive value in the tool geometry table. Some may be shorter than the reference tool and they have a negative value in the tool geometry table. This method sometimes confuses operators, because: 1. The tool lengths measured do not correspond to the physical lengths of the tools. 2. The sign of the tool offsets is sometime plus and sometime minus. In the example screen, tool #2 is the reference tool with a length of zero. Longest tool - this method uses the longest tool available as the reference tool. It has a tool offset length of zero. Now all the tool geometry offsets are negative, since they are all shorter than the longest reference tool. The tool lengths offset still do not correspond well with the actual lengths of the tools. This method works as long as the longest tool is is always in the tool changer. Otherwise the tool must be loaded just as a reference tool. Another problem is that the longest tool may not be able to be positioned on the top of tall workpieces to establish the Z-axis workpiece coordinate system offset. In the example screen, tool #8 is the reference tool. Document # MWA-072-EN_01_ Page 14 of 20

15 Because the offsets are all negative values and it is easier to establish a size limit for tool length geometry offsets, it is easy to error-proof the values entered using the CNCs Wrong Operation Prevention Function. Spindle nose - this method uses the spindle nose as the reference tool. Now all the tool geometry offsets are positive since all tools are longer than no tool. The values stored in the offset tables will correspond reasonably well with the actual physical length of the tools. The spindle nose is always available for measurement and it will always be able to reach the top of any part to perform the measurement for the Z-axis workpiece coordinate offset. This method creates the least confusion to operators. Note that in the example screen, all the tools have positive lengths the tool nose (T00) is the tool with a zero length. Though spindle nose is often used as the reference tool, it should be noted that if a G49 is programmed, cancelling the tool offset, the Z- axis will move in the direction of the part, potentially causing a crash. In practice, users of the spindle nose method do not program G49 and rely on G28 to temporarily disable the tool length offset as it returns the Z-axis home. Because the offsets are all positive values and it is easy to establish a size limit for tool length geometry offsets, it is easy to error-proof the values entered using the CNCs Wrong Operation Prevention Function. Note: The reference tool chosen must be used during setup to set the workpiece coordinate system offset value in the Z-axis, but it does not have to be actually used in the current program. Since both the longest tool method and the spindle nose method ensures that values are Procedure to Measure Tool Length Geometry Offset Values with a Reference Tool 1. Place the tool offset gage on a clean, stable work surface that is accessible by all the tools to be measured, including the reference tool (including the spindle nose if it is the reference tool). The surface can be the vice, fixture or the machine table. An electronic or dial indicator gage can be used. 2. When using the most common tool or longest tool method, place the reference tool in the spindle. This can be done manually or by executing a T-code and an M06 in the MDI mode. When using the spindle nose as a reference tool, remove any tool from the spindle manually or program and execute a T00 M06 in the MDI mode. 3. Use the jog buttons or an electronic handwheel to position the reference tool close to and above the tool offset gage. Document # MWA-072-EN_01_ Page 15 of 20

16 4. Switch to incremental jog or continue to use an electronic handwheel. In either case, select the smallest increment of movement available. 5. Lower the reference tool (or spindle nose) until: a. The light is displayed and/or audible alarm is triggered on an electronic tool offset gage b. There is a reliable reading on the dial indicator. When a reliable reading is established, set the dial to zero. 6. Press the function button on the CNC MDI panel. 7. Press the [REL.] soft key to display the relative coordinate system position page. 8. Enter Z0 in the key input buffer and press the [PRESET] soft key the Z-axis relative zero position is now set to the reference height of the tool offset gage. 9. Retract the Z-axis and place the tool to be measured in the spindle, either manually or by programming and executing a T-code and an M06 in the MDI mode. 10. Using incremental jog or an electronic handwheel with the smallest increment for movement selected, lower the tool until: a. The light is displayed and/or audible alarm is triggered on an electronic tool offset gage. b. The dial returns to the same zero displayed with the reference tool. 11. Press the function button on the CNC MDI panel. 12. Press the [OFFSET] soft key to display the tool offsets page. 13. If necessary, press the key on the MDI panel until the tool offset that matches the tool number being measured is displayed. 14. Press the,, and cursor keys to highlight the specific tool number being measured in the GEOM (H) column H is the length offset. Document # MWA-072-EN_01_ Page 16 of 20

17 15. Enter the Z letter address in the key input buffer and press the [INP. C.] soft key to copy the Z-axis relative position to the selected offset. This stores the difference in length between the reference tool and the tool being measured. In the example screen to the right, the offset will be stored in tool offset number 3 (H03), the current value of the Z-axis relative position is positive 2.25-inches. That means the tool is 2.25 inches longer than the reference tool. After pressing the [INP. C.] soft key, the value of offset 3 is inches, the value copied from the Z-axis relative register. 16. Repeat steps 9 through 15 for any addition tools to be measured. Note: some operators use a thin piece of paper as a "feeler gage" and a flat surface to establish the reference tool datum and measure tool offsets. Others may be using a gauge block as a feeler gauge. However, tool offset gages are inexpensive and fast - and they are less likely to damage tooling in the hands of a less experienced operator. See a video demonstrating these steps, here. 3.4 Touch-off Method The touch-off method is used when there are no standard tools in the tool changer, so every tool used in the program must be measured for every job setup. Note the X and Y workpiece coordinate system offsets are set the same whether using the reference tool or touch-off tool methods. See the procedure in Section 2. However, the Z-axis workpiece coordinate system offset must be set to zero when using the touch-off method Procedure for Measuring Tool Length Geometry Offsets using the Touch-off Method This procedure must be repeated once for each tool used in the part program, regardless if it has a tool length coordinate offset set from a previous job setup. 1. Make sure that the workpiece coordinate system offset used in the part program is active. Check the modal G-codes on the position page. If it is not active, activate it using MDI mode. Also check that the Z-axis relative position is zero at the home position (the default when the CNC is powered-up). 2. Retract the Z-axis and place the tool to be measured in the spindle, either manually or by programming and executing a T-code and M06 in the MDI mode. Document # MWA-072-EN_01_ Page 17 of 20

18 3. Use incremental jog or an electronic handwheel with a suitable increment and lower the tool until it is about a one inch above a clean flat surface on the part. If one is not available, first skim the top of the part with a facing tool to create a suitable measurement surface. 4. Switch to incremental jog mode or continue to use an electronic handwheel. In either case, switch to the smallest increment available. 5. Very slowly move the Z-axis down until it is almost touching the part, leaving a paper thickness gap or more. 6. Press the function button on the CNC MDI panel. 7. Press the [OFFSET] soft key to display the tool offsets page. 8. Press the key on the MDI panel until the tool offset that matches the tool number being measured is displayed. 9. Press the,, and cursor keys to highlight the specific tool number being measured in the GEOM (H) column H is the length offset. 10. Take a thin piece of paper and test if it can be inserted between the tool and the top surface of the machine. If the paper moves easily, jog the axis down one increment and re-test the fit. 11. Repeat step 9 until there is a slight mechanical resistance when inserting the paper between the part and tool. The tool is now one paper thickness above the top of the part. 12. Enter the Z letter address in the key input buffer and press the [INP. C.] soft key to copy the Z-axis relative position to the tool length offset. 13. Enter the thickness of the paper (.004 for example) in the key input buffer using the CNC MDI keyboard and press the [INPUT+] soft key to compensate for the fact that the tool was not actually touching the part. Alternatively, use the tool wear offset to fine tune the tool length after measuring a part. 4 Summary FANUC s Direct Input of Workpiece Origin Setting Value Measured and Tool Length Measurement features make it easy to establish workpiece coordinate system and tool length geometry offsets. All the values entered by the operator are known and constant half the diameter of the edge finder and the thickness of the paper. Calculations and data entry are minimized, error-proofing the process. The measurement values are calculated and entered automatically with simple soft key actions. The reference tool method using the spindle nose is fast because it uses an inexpensive tool offset gage and eliminates the re-measuring of standard tools. It also reduces operator confusion since all the signs of the offset values are positive and the dimensions of the values are roughly the visible length of the tool. Document # MWA-072-EN_01_ Page 18 of 20

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20 1800 Lakewood Boulevard Hoffman Estates, IL FANUC-US ( ) Find more information at Technical data is subject to change without prior notice. No part of this document may be reproduced in any form. All rights reserved Document # MWA-072-EN_01_1404