For more details, please check EASYCNC YouTube video here.

 

Analysis of common faults of servo motors
 

 

First, the motor overcurrent overload alarm
1. The motor is improperly installed or the mechanical load is too large, resulting in overload alarm.

Solution: Install correctly, reduce mechanical load or replace the high-torque motor.

2. Water ingress of the motor.

The motor stator coil is less than 10MΩ insulated to ground, and the power socket is short-circuited between phases.

Solution: Cleaning and drying stator insulation resistance should be greater than 100MΩ, if the requirements are not met, replace the power socket or motor stator.

 

This is due to poor waterproof treatment, which causes a large amount of cutting fluid to enter the motor, so that the motor insulation layer is damaged and the ground is short-circuited. Previous article:FANUC motor is flooded, how to measure? 

3. When the user replaces the encoder by himself, he forgets to install the coupling or the encoder detects errors. Causes an alarm. Solution: Replace the encoder or coupling with a new one.

 

 

 

   

Second, the motor overheating alarm (430 alarm)

1. Due to poor waterproof treatment, a large amount of cutting fluid enters the motor, so that the motor insulation layer is damaged and the ground is short-circuited.

2. The temperature sensor detects the error and the temperature sensor is damaged. The normal value should be between 55-80kΩ, and the resistance value varies with ambient temperature. Solution Method: Send the motor back to the company for repair;

3. Improper installation of the motor and excessive mechanical load cause overheating alarm. The solution should be installed correctly to reduce the mechanical load;

4. Motor brake coil with brake short circuit or open circuit. The brakes are not open, causing excessive load on the motor. The reason is due to the imprecise voltage capacity supplied to the brake coil. The brakes do not open completely. Solution: Replace the brake and have a separate power supply. α series electric mechanism The coil resistance value of the actuator is about 230Ω, and the coil voltage is 90V. αi series motor brake coil resistance 26Ω, coil voltage is 24V.

3. The motor coil is bad

 

Servo motor power line:

A---U (drive side) B---V (drive side)

C---W (drive side) D---G (ground side)

Motor coil diagnostics:

Measured with a megohmmeter 500V

Good: >100MΩ

Start aging: 10~100MΩ

Severe aging: 1~10MΩ

Faulty: less than 1MΩ

 

 

4. The motor holding brake is broken

 

Why is the motor holding brake easy to break?  The servo axis controlled by the holding brake is basically the gravity axis, the Z axis of Lijia, and the X axis of the lathe, so the load is generally relatively large, and the large load for a long time is easy to make the motor hot, and at high temperature, the hot wear plate is easy to wear, so that after a few years, the holding brake fails, and it falls down during the emergency stop. 

 

For more details, please check EASYCNC YouTube video here.

 

After entering the system, how to package the backup data?

 

      The new version of the 0I-C system can back up SRAM files in the normal boot state of the system, which can only be backed up under BOOT in the past, the steps are as follows:

1 PRM3116#0=1 

2 EDIT MODE 

3 Press SYSTEM—ALL I/O--->---> until M-CARD is displayed 

    

 4 After pressing the operation key, the following screen appears:

  

 5 Press the emergency stop and select the EDIT mode and press SAVE to appear after the following screen appears:

  

6 DISPLAY when BACKUP is complete:

  

7 The LOAD SRAM method is the same as above

 

For more details, please check EASYCNC YouTube video here.

 

Adding M code to FANUC is as simple as that

 

More and more machine tools, need to add M code, used to control peripheral fixtures or other actions, how to write the simplest ladder diagram, to achieve this function?

1 Download the original ladder diagram from the machine.

2 Open the machine ladder diagram on the computer and find the DECC function command.

 

As shown in the figure above, the DECB function quality number is SUB25, followed by F0010, which represents the decoding instruction, and the translation is M code.

3 Check several consecutive DECBs as shown below:

 

4 Add M code, according to the above picture according to the cat drawing tiger, insert a line of function instruction SUB25, for example, we want to add M60, M61, M62, M63 these 4 instructions, insert the following ladder diagram:

 

When M60 is executed, R604.0=1 (on);

When M61 is performed, R604.1=1 (conduction);

When M62 is performed, R604.2=1 (conduction);

When M63 is performed, R604.3=1 (on);

R604 is the starting address, we can also start with R700 (any value, but cannot be used in the program)

5 Finally, the M command end signal, very important, if you do not add this line of ladder diagram, after your M code execution is completed, the machine will not execute later, pause.

Search for G4.3 (FIN auxiliary code end signal) in the original ladder

 

G4.3 not only ends auxiliary code M, but also technical auxiliary code S, T. So this program uses a transition instruction R653.0 (MEND) to search for coil R653.0, as shown below:

 

We added R604.0 and X99.0 (a position detection switch, such as a door switch, when we execute M65, the door opens, touches the X99.0 detection switch, it is considered in place, and the M command ends).

When M64 is executed, R604.0=1 is immediately turned on, and R653.0 in the figure above is turned on, causing G4.3 to turn on and the M command to be completed.

When M65 is executed, R604.1=1 conducts immediately, we can let R604.1 trigger a Y signal, control the hydraulic valve, push the door to open, open and hit the X99.0 detection switch, X99.0=1, the R653.0 in the figure above is on, causing G4.3 to turn on, and the M command is completed.

6 Save, compile and upload the edited ladder diagram to the FANUC system.

 

Of the several variables that determine whether and how well a CNC machine tool works over time, the power supply may be the most important. The power supply for your Fanuc CNC mill or lathe has several elements that may fail without warning or begin to malfunction. You want to be aware of how this part of every machine tool can be vulnerable to failure, what can go wrong, and how a CNC repair tech can fix power issues. Good CNC machine maintenance practices can prevent some issues, but this post focuses on finding power supply issues. A quick review of the subsystems that run a machine tool will make it clearer how electrical issues could disable a machine or degrade its performance.

A Quick Review of Fanuc CNC Power Supplies
A Fanuc CNC tool will typically have several AC and DC power supplies for internal subsystems. There may be a power supply for the printed circuit board (PCB), the monitor, and the input/output card, the door interlock circuit, and a connection to the external power source. The machine will also have one or several fuses, which can wear out or blow.

Some performance issues with your Fanuc lathe or mill may be caused by the site’s power supply. If the facility gets a low-quality (variable and/or weak) supply of power, any electrical device is likely to have performance problems. Over time, relatively sensitive parts may be degraded by the peaks and valleys of the location’s power supply. However, most power issues in CNC machine tools are probably going to be found in one or more components of the tool.

Understanding Possible Failure Points
Your CNC mill, grinder, router, or lathe will have subsystems that take power from the workshop, which gets power from the local electrical grid. Once the current gets to the machine it will go through various power handling devices that step down the voltage, convert AC to DC or the reverse. That voltage will then go to solenoids and motors that run servos, hydraulics systems, spindle drives, monitors, and so on. 

That last paragraph covers many of the potential failure points for a Fanuc CNC machine tool’s power system. The details are a bit more involved, but at the same timeAssume the machine gets a good and steady voltage from the primary power source and the power cord is intact, you are left with a few sources of trouble inside the device. Many of your power issues are going to come from things like:

Current at the input or output side
Reversed polarity
Temperature issues
Age (normal wear)
Missing external components
The last item is the only that will be easy to identify and deal with but anyone with CNC machine maintenance experience will be able to find and fix other power problems.

Troubleshooting Power Problems
Ideally, the Fanuc machine itself will send a signal that indicates what kind of power issue has developed. Sometimes, the first sign of trouble will be when a machine tool component stops working or the machine shuts down or speed drops. Whatever the specific symptom, a CNC repair technician or engineer will need to do some analysis to track down the failure point and make a repair.

Never forget the possibility that something simple went wrong. We’ve all had devices turn off because someone unplugged. If the building has power, it could be the specific machine’s power cable or a blown fuse.

The fuses will take a little work to evaluate. The technician needs to find the relevant fuse, pull it and check that voltage goes in and comes out. If not, the associated power supply might be bad. Look for an LED indicator on the power supply. If there is one, you naturally should expect to see a light. If the light is absent or very weak, you may have found the problem. Check the power unit with a voltmeter.

Once those possibilities have been dismissed, a technician will have to evaluate some of the machine’s internal components. Aside from the internal power supply working, it needs to deliver the right amount of voltage, consistently. If voltage fluctuates dramatically or goes too low, the machine’s performance is sure to be compromised.

How much degradation or variation is acceptable? A 24v DC power supply that actually delivers anything below 20 volts will cause problems. On the other hand, a variation of two or three volts in a 380v power source is not a problem but a drop of 10 to 15 volts may indicate that part will need to be refurbished or repaired in the near future.

In some cases, the bad Fanuc CNC part will need to be expertly repaired or replaced. Many machine tool owners see the value in buying refurbished power supplies or calling on experienced technicians to diagnose and repair a defective power supply. Ideally, you will also have extra fuses on hand.

Mitsubishi  System Testing Capabilities

Capable of testing Mitsubishi Versatile Drive and Motor Series components in a complete system including; Drives, Power Supplies, Servo Amplifiers, HMIs, ac Servo Motors and interface and I/O components.

Key Features:

Full system testing utilizing Mitsubishi operator interface controls (simulating customer applications)
Test system monitoring including fault detection
Programmable control limits, with upper and lower control settings
Our Mitsubishi Testers Include:

MDS-A, MDS-B & MDS-C series:

Single Axis Servo Drives
Dual Axis Servo Drives
Power Supplies
MDS motors
MRJ Series:

MR-J2 motors
MR-J2S motors with S encoders
H series motors:

HC-MF
HA-FF
HC-SF
HC-RF

Siemens Testing Capabilities

Capable of testing SIEMENS intelligent components in a complete system including; Drives, Power Modules, Power Supplies and Motors.  This proprietary tester is able to match digitized motor feedback with the mating Drive and Power Supplies and run them as a complete system in a simulated field set up.

Key Features:

Digitized controls monitor component efficiency
Feedback health data on overall condition of components
Provide fault history and real time fault data
Automatic shutdown if critical parameters fall outside OEM limits
Our SIEMENS Testers Include:

SimoDrive 611U – Universal Servo System Tester
SimoDrive 611U – Spindle Amplifier/Spindle Motor System Tester
SimoDrive 611D – Digital Servo System Tester
Sinamics S120 – Motion Control System Tester
We provide full system testing of:

SIMODRIVE (611): Servo Drives/Power Modules/Power Supplies
SINAMICS (S120): Servo Drives
SIMOTICS: Motors, low voltage DC through highly dynamic servo motors including ac/DC high voltage applications
Complete List of Siemens Repair Capabilities

Category    Series    Type    Models
Drives    Simoreg    DC Drive    6RA2XXX-XXXXX-XXXX
Drives    Midi Master    Variable Frequency Drive    6SE322X-XXXXX-XXXX
Drives    Simovert     Inverter    6SE4XXX-XXXXX-XXXX
Drives    Micro Master 440    Variable Frequency Drive    6SE6440-XXXXX-XXXX
Drives    Micro Master 430    Variable Frequency Drive    6SE6430-XXXXX-XXXX
Drives    Micro Master 420    Variable Frequency Drive    6SE6420-XXXXX-XXXX
Drives    Micro Master 410    Variable Frequency Drive    6SE6410-XXXXX-XXXX
Drives    Simovert Master Drive    Variable Frequency Drive    6SE7XXX-XXXXX-XXXX
Drives    Simovert    Variable Frequency Drive    6SE8XXX-XXXXX
Drives    Micro Master    Variable Frequency Drive    6SE9XXX-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1111-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1112-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1113-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1114-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1115-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1117-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1118-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1121-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1123-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1124-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1128-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1130-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1135-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1140-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1145-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1146-XXXXX-XXXX
Drives    Simodrive 611    Servo Drive Modules    6SN1151-XXXXX-XXXX
Drives    Sinamics S120    Servo Drive Modules    6SL3XXX-XXXXX
Drives    Simoreg    DC Drive    6RA2XXX-XXXXX-XXXX
Power Supply    Simodrive    Power Module    6SN1118-XXXXX-XXXX
Power Supply    Simodrive    Power Module    6SN1123-XXXXX-XXXX
Power Supply    Simodrive    Power Module    6SN1145-XXXXX-XXXX
Power Supply    Simodrive    Power Supply Board    6SC6XXX-XXXXX-XXXX
Power Supply    Sinamics S120    Power Module    6SL3XXX-XXXXX
Power Supply    Sitop    Power Supply    6EPXXXX-XXXXX
Motors    Simotics    Servo Motor    1FT6XXX-XXXXX-XXXX
Motors    Simotics    Servo Motor    1FT7XXX-XXXXX-XXXX
Motors    Simotics    Servo Motor    1FKXXXX-XXXXX-XXXX
Motors    Simotics    Servo Motor    1PHXXXX-XXXXX-XXXX
Motors    Simotics    Servo Motor    1PM6XXX-XXXXX-XXXX
Motors    Simotics    Servo Motor    1PM4XXX-XXXXX-XXXX
PLC    Simatic S5    PLC Module    6SE5XXX-XXXX
PLC    Simatic S7    PLC Module    6SE7XXX-XXXX
HMI/Computer    Simatic    Simatic Operator Panel    6AV1XXX-XXXXX
HMI/Computer    Simatic    Simatic Operator Panel    6AV3XXX-XXXXX-X
HMI/Computer    Simatic    Simatic Operator Panel    6AV5XXX-XXXXX-X
HMI/Computer    Simatic    Simatic Operator Panel    6AV6XXX-XXXXX-X
HMI/Computer    Simatic    Simatic Operator Panel    6AV7XXX-XXXXX-X