Common problems and solutions in WEDM

1. Broken wire

1. The discharge state is not good
——Reduce the P value. If the P value is greatly reduced and the wire is still broken, consider reducing the I value until the wire is broken. This operation will reduce the processing efficiency. If the wire breaks frequently, please refer to the following to find out the root cause of the broken wire.

 2. The flushing state is not good. For example, the upper and lower nozzles cannot be processed on top of each other, or when open processing is performed, the wire breakage is usually in the processing area.

—— Reduce the P value and check whether the upper and lower water nozzles are damaged. If damaged, please replace them in time.

3. The conductive block is severely worn or too dirty, and the broken wire is usually near the conductive block.

- Rotate or replace the conductive block and clean it.

4. The guide wire part is too dirty, causing the wire to be scraped. Usually, the broken wire is located near the guide wire part.

- Clean the guide wire parts.

5. Too much tension

- Turn down the wire tension FW in the parameters, especially when cutting with a taper.

6. There is a problem with the quality of the electrode wire and workpiece material.

- Replace the electrode wire, lower the P and I values until the wire stops.

7. The waste wire in the waste wire barrel overflows and contacts the machine tool or the bottom surface, causing a short circuit. Usually, the wire will break just after starting processing.

——Put the overflowing waste wire back into the waste wire bucket, and clean up the waste wire bucket in time.

8. Broken wire at the wire take-up wheel

——Check the wire pressing ratio of the wire take-up reel, the standard value is 1:1.5～1.6.

9. The cooling water of the conductive block is insufficient, and the broken wire is usually near the conductive block

- Check the cooling water circuit.

10. The conductivity of deionized water is too high, usually the broken wire is in the processing area

——Check the conductivity of water, if it is out of tolerance, replace the resin in time.

11. The quality of deionized water is poor, and the broken wire is usually located in the processing area.

——If the water in the water tank is cloudy or smelly, or there is a problem with the pure water added to the machine tool, the water tank should be cleaned in time and the filter paper core should be replaced.

12. The wire is broken, the waste wire is embedded in the ceramic guide wheel of the lower machine head or the bearing of the guide wheel is inflexible.

——Clean and re-adjust and install the ceramic guide wheel, and replace the guide wheel bearing if necessary.

13. The balance wheel vibrates too much, and the wire movement is not smooth.

——To correct the wire speed, use a tensiometer to correct the wire tension.

2. Low processing speed

1. It is not processed according to the standard process, and the distance between the upper and lower nozzles is higher than 0.1mm from the workpiece

- As far as possible veneer processing.

 2. The craft file created is incorrect.

—— Correctly input relevant processing requirements and generate reasonable process documents.

3. Modify the processing parameters, especially reduce the P, I value too much will lead to a significant reduction in processing speed.

——It is necessary to modify the discharge process parameters reasonably.

4. The flushing state is not good, and the standard flushing pressure cannot be reached.

——If it is true that the veneer cannot be processed, it is necessary to correctly understand the processing speed.

5. The deformation of the workpiece leads to unstable discharge state during processing, especially trimming.

—— Reasonably arrange the process and control the deformation of the material.

 6. If ACO (Automatic Process Optimization) is selected in the parameters, the machining efficiency will be reduced in the case of unstable machining.

——In the case of stable cutting, the ACO function can be cancelled.

7. For workpieces with many corners, using high-precision parameters can achieve higher accuracy, but it will reduce efficiency.

——Appropriately reduce the STR value of the corner strategy to increase the processing speed.

 8. Mode 30 machining, poor discharge stability and slow speed

----- Modify the parameter UHP, can increase 2 values.

9. The trimming speed is slow.

 ——The relative processing amount of each knife can be changed to a smaller value. If the speed of trimming cut one is to be increased, the offset of the main cut can be reduced by 0.005mm～0.01mm.

 

10. The cutting efficiency of the main cutting is lower than before.

  - Timely maintenance of the machine tool.

 

3. There are traces on the surface

1. There is a problem with the quality of the electrode wire.

- It is recommended to use original consumables.

2. There is a problem with the workpiece material, or the material contains impurities.

- Replace the workpiece material.

3. The release of local internal stress in the workpiece will lead to the occurrence of line marks in individual positions of the workpiece.

—— Optimize the processing technology and reduce the internal stress and deformation of the material.

4. The temperature of the working fluid is too high or the temperature changes too much.

——The liquid temperature must be controlled by a refrigerator, and a suitable ambient temperature must be ensured.

5. The external environment of the machine tool is harsh and the vibration is large.

——Improve the external environment of the machine tool.

6. The conductive block is seriously worn.

- Rotate or replace the conductive block.

7. The cooling water of the upper and lower conductive blocks is insufficient.

- Clean relevant parts.

8. The guide wire is too dirty.

——Maintain the guide wire part.

9. The working fluid is too dirty.

- Clean the tank and water tank and replace the working fluid.

10. Observe whether the discharge state is stable and whether there is a short-circuit back-off phenomenon during trimming.

- If there is a short circuit in the trimming, the UHP value can be increased by 1~2.

11. If the discharge current and voltage are normal when trimming, but the speed is very low.

- The relative offset can be reduced. 12. The flushing state is not good, and the standard flushing pressure and jet shape cannot be reached.

——Check whether the upper and lower nozzles are damaged, and replace them in time if they are damaged.

13. The wire tension is unstable.

- Calibration of wire speed and tension.