Many people take a look at 411, the first reaction is that the servo is bad. But over time you will find that there are often more mechanical things than electrical things. The following situations, is the maintenance of the head of the most seen.
- Cutting load is too large
This is the most common reason, there is no one. For example, a cut is too hard, the tool is worn bald and still use, feed speed soared fast, the workpiece material is ridiculously hard.
All of these situations will make the axis go "hard”, the servo motor has to make more effort to keep up with the instruction. Once the load more than the system can withstand the range, the position can not keep up with the → error is too large → alarm 411, so come on.
- In addition to cutting loads, mechanical resistance will also be similar problems!
For example, the guide rail is out of oil, the screw resistance is large, the guide rail crawling. These conditions are especially common on older machines.
If the performance of the servo system itself is degraded, it will also lead to the axis can not keep up with the command. Commonly used servo motor aging, motor output torque becomes small, amplifier output is not normal, drive module overheating. Some machine tools are running for a while before the alarm, this is most likely to drive the temperature up, the output capacity down.
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Encoder or feedback signal is not normal
The system relies on encoder feedback to know where the axis is. Feedback signal problems, the system will misjudge the position deviation. Typically, the encoder is broken, the encoder wire is loose, the feedback line has poor contact, and the signal is disturbed.
These faults sometimes behave very cunningly, occasionally report an alarm, reset and can be good for a while. This situation is actually not uncommon in the field.
- Mechanical wear or clearance
When a machine tool is used for a long time, many mechanical parts will wear out, such as ball screws with large gaps, loose couplings, and worn gears.
These problems can slow down the axis response and the system detects a larger following error. Over time, it may trigger a 411 alarm.
- Irrational servo parameter settings
Sometimes the machine itself is fine, but the parameter setting is not reasonable. Position error tolerance range is set too small, the servo gain is not adjusted properly, these will affect. This situation usually occurs after the replacement of amplifiers; after the replacement of motors; after the parameter recovery. If the parameters are not re-optimized, it is easy to alarm frequently.
The method of on-site troubleshooting 411
Running the field to repair the machine, in fact, there is an order. Many masters are so step by step.
- Step 1: See which axis alarm
Alarm information will be clearly written on the axis, such as the X-axis, Y-axis, Z-axis. First determine which axis is the problem, and then focus on checking that axis-related components.
- Step 2: Check the machinery
This step is the most critical. You can try to manually disk disk axis (under the state of power failure), listen to any noise, feel whether there is no jamming. At the same time, check the guide rail lubrication is good, how the status of the screw, coupling is not loose. A lot of 411 alarm, and finally found out that the mechanical resistance is too large.
- Step 3: Try to reduce the load
Can do a simple test. The feed rate down; empty run a program; not cutting. If the alarm is gone, it is basically certain that the load problem.
Look at these key points to see if the amplifier is hot, the motor is not abnormally hot, and there are no other servo alarms. If possible, try to change the amplifier.
- Step 5: Check the encoder and feedback line
Many problems are actually here. Focus on checking the encoder plug, the wire is not broken skin, wiring is not loose. If there are spare parts, try to change a wire.
- Step 6: Check the servo parameters
If the above are normal, then look at the following error limit parameters and servo gain. This step is recommended to let the experienced master to get.
- Step 7: Change parts test
If you still can not find the reason, you can try to change the servo motor, change the servo amplifier. On-site troubleshooting this trick works best.
How to make 411 alarm less appear
A lot of 411 alarms can be avoided when machine tools are well maintained.
Daily recommendations:
* Regularly add oil to the guide rail screw.
* Don't keep doing too much heavy lifting.
* Check couplings and mechanical parts regularly.
* Check the encoder cable to see if it is still good.
* Keep an eye on the operating status of the servo system.
A lot of machine tools start to alarm frequently, precisely because of long-term neglect of maintenance.
