Here is the troubleshooting method for tapping faults in the vertical machining center of FANUC system:
Troubleshooting Broken Faucets
– Check the parameter settings:
– Check the feed rate (F value) and spindle speed (S value) in the tapping program. The correct relationship between feed rate and rotation speed must meet the pitch requirements of the thread, that is, F = S × pitch. For example, when tapping an M8×1.25 thread and the rotation speed is set to 1000 rpm, the feed rate should be set to 1250 mm/min.
– Make sure the tapping method settings are correct. If rigid tapping and flexible tapping modes are selected appropriately, rigid tapping requires high synchronization of the machine tool and is suitable for high precision situations; flexible tapping has a certain buffer to avoid damage to the tap.
– Check the condition of the bottom hole:
– Measure the bottom hole diameter again to see if it meets the standard. For example, for ordinary large threads, the bottom hole diameter is usually approximately equal to the nominal diameter minus the pitch.
– Pay attention to the accuracy of processing the bottom hole. Improper cylindricity of the bottom hole can also cause the faucet to break. The processing quality of the bottom hole must be ensured.
– Improve chip removal:
– Adjust the flow rate and pressure of the cutting fluid so that it can effectively evacuate the chips when feeding.
– For tapping blind holes, helical flute taps can be used, which have good chip evacuation performance and can evacuate chips upward.
Troubleshooting for out-of-tolerance thread accuracy
– Inspection and replacement of tools:
– Use a magnifying glass and other tools to check the tap edges for wear. Heavily worn taps should be replaced in time.
– Select taps with good quality and high precision to ensure that the manufacturing accuracy of the tap meets the processing requirements.
– Detection and adjustment of machine tool precision:
-Use professional inspection tools to check the axial and radial runout of the machine tool spindle. If the runout exceeds the range, the spindle must be repaired or adjusted.
– Check whether the machine tool worktable is level. If it is not level, it will affect the verticality of the tapping and therefore the accuracy of the thread.
– Inspection and correction of the program:
– Carefully check the thread pitch, starting position, ending position and other parameters in the program to ensure that they conform to the processing requirements.
– When processing threads of different specifications, the program parameters must be changed accordingly.
Troubleshooting Overload Alarm by Tapping
– Reduce cutting resistance:
– Pre-treat the workpiece material, such as normalizing, annealing and other heat treatments, to reduce the hardness of the material.
– Optimize processing technology, reasonably arrange processing allocation, and ensure that the allocation is uniform.
– Check the motor and variator:
– Check if the motor current is within the rated range. Excessive current may indicate that the motor is overloaded.
– Check the parameters and working status of the inverter, check if there is an alarm code, and perform troubleshooting according to the code prompts. If the inverter has poor heat dissipation, it may cause abnormal operation, so check its heat dissipation device.
The tapping of the FANUC system vertical machining center always stops and the pause time varies. The main reasons are:
Configuration problem
– Unreasonable acceleration and deceleration time constants: During the tapping process, if the acceleration and deceleration time constants of the spindle and tapping axis are set incorrectly, the movements of the two will not match well, causing the tapping to pause. For example, if the acceleration and deceleration time is too long, the tapping spindle will pause before reaching the set speed.
– Timing Parameter Setting Error: When rigid tapping, the timing parameter setting error of the spindle and tapping axis will prevent both from maintaining accurate synchronization during the tapping process, thus which will cause a pause. If the setting of the tapping axis position loop gain parameter is unreasonable, it will affect the following performance of the tapping axis and cause pause.
Mechanical transmission problem
– Loose or worn drive chain: If the gears, belts, couplings and other components of the machine tool drive chain are loose, worn or have excessive gaps, it will result in unstable power transmission during the tapping process and will cause intermittent movements of the tapping spindle. . Sexual break.
– Tap tightening problem: the tap tightening is not firm or the tightening precision is insufficient. The tap will oscillate or move while tapping, increasing tapping resistance. The machine tool control system will suspend tapping to protect the tool and machine tool.
control system problems
– Signal interference: There is strong electromagnetic interference around the machining center, or the control system is poorly grounded, which will cause the control system to receive bad signals, causing tapping to be suspended .
– System program failure: Errors, faults or losses in the CNC system program will affect the normal operation of tapping and cause abnormal pauses in the movement of the tapping axis.
Cutting Condition Problems
– Excessive cutting force: unreasonable selection of tapping parameters, such as too fast feed rate and too low rotation speed, will result in too large cutting force, exceeding the bearing capacity of the machine tool or of the tap, causing the machine tool to hang. tapping to avoid damage.
– Poor chip removal: chips accumulate in the hole, increasing tapping resistance. When the resistance reaches a certain level, the machine tool stops tapping and waits for the chips to be discharged before continuing.
To determine the reasonable value of the acceleration and deceleration time constant in the FANUC system, you can refer to the following methods:
Reference machine manuals and technical documentation
Manuals and technical documents provided by the machine tool manufacturer will give the recommended acceleration and deceleration time constant values. These values are determined according to the mechanical structure of the machine tool, motor performance and other characteristics, and can be used as an important element. reference.
According to processing technology and materials
– Cutting feed: When processing materials with high hardness, such as titanium alloys, in order to reduce the cutting force and tool wear, the acceleration and deceleration time constant should be extended appropriately and the feed speed change rate should be reduced when processing more gently; materials such as aluminum, the corresponding shorten the time constant to improve the processing efficiency.
– Rapid feed: When performing rapid positioning or no-load stroke movement, the acceleration and deceleration time constant can be appropriately reduced within the allowable range of the machine tool to shorten the positioning time, but care should be taken to avoid impacts caused by excessive acceleration and deceleration.
With system diagnostic and monitoring capabilities
The FANUC system provides diagnostic parameters and monitoring screens. For example, during rigid tapping, the values of diagnostic parameters 452 and 453 can be observed to adjust the acceleration and deceleration time constant. Generally, the value of 453 should be less than 10.% to ensure the accuracy of the synchronization of the spindle and tapping axis.
Perform cutting tests and optimization adjustments
– Preliminary settings: First set the acceleration and deceleration time constant according to the above experiment or method. For example, the acceleration and deceleration time constant after cutting feed interpolation is 1622, which can be set to a value between 100 and 500 ms.
– Trial cutting evaluation: carry out trial cutting processing to observe movement stability, processing accuracy, tool wear, etc. during treatment. If problems such as vibration and tolerance exceedances occur, the acceleration and deceleration time constant may be unreasonable.
– Gradual optimization: Based on the test cutting results, gradually adjust the acceleration and deceleration time constant in small increments, such as adjusting 10%-20% each time, and try cutting again until ‘so that the best treatment effect is obtained.
Adjust the acceleration and deceleration time constant via the FANUC system monitoring screen
1. Enter the monitoring screen
– First, press the “SYSTEM” button on the FANUC system control panel. Then find the “Diagnosis” or “Parameter” option in the system menu (the specific name may be slightly different depending on the system version and machine tool manufacturer’s settings) and find the corresponding monitoring screen after entering.
2. Find the display of parameters related to acceleration and deceleration
– In the monitoring screen, you must find the parameters related to the acceleration and deceleration time constant. For example, for the acceleration and deceleration time constant of the feed axis, there may be a special parameter number (such as parameter No. 1622, used for the acceleration and deceleration time constant deceleration after interpolation of the cutting feed). These settings will display the currently set values.
– For rigid tapping, pay special attention to parameters such as diagnostic parameters 452 and 453. The value of parameter 453 should be less than 10% as much as possible. It can help judge the timing accuracy of the spindle and tapping axis, thereby indirectly guiding the adjustment of the acceleration and deceleration time constant.
3. Adjust according to display data
– If it turns out that the parameter value display on the monitoring screen does not meet expectations, for example, the value of timing precision parameter 453 is too large, the time constant will be changed. acceleration and deceleration must be adjusted.
– Return to the “Parameter” setting interface (usually there is a separate “Parameter” option in the system menu) and find the corresponding acceleration and deceleration time constant parameter (such as parameter No. 1622 below). -above). According to the actual situation of the machine tool and the trial cutting effect, change the parameter value in appropriate increments (e.g. 10-20ms for each setting).
– After the adjustment is completed, perform the treatment operation again and observe the parameter changes on the monitoring screen and the actual treatment effect, such as smoothness of movement, precision of tapping, etc. If the treatment effect does not improve or even deteriorates, the parameter values should be readjusted until satisfactory treatment results are obtained.
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