What are the causes of washboard lines in WEDM? Wire cutting mainly depends on the movement of electrode wire. Because the electrode wires are mostly molybdenum wires, the change of running direction will lead to regular washboard lines on the machined surface of the workpiece. If the washboard lines are too obvious, there is a risk that the workpiece will be scrapped.

 

1. When the molybdenum wire is loose or the tightness difference between the molybdenum wires at both ends of the wire storage barrel is large, the molybdenum wire of the middle-walking wire will shake badly, and the deflection will increase, which will inevitably lead to overfeed and short-circuit stop feeding.

 

2. The running of the guide wheel bearing is out of order, resulting in different negative forces or axial movement during forward and reverse steering. At the same time, if the negative force of the guide block or guide wheel is large, resulting in a serious difference between the positive and negative tension of molybdenum wire in the working area, washboard lines will also appear.

 

3. Uneven feeding related to wire feeding and reversing will lead or lag, which will form a step shape on the oblique line and circular arc, similar to washboard pattern. In a word, one of the main reasons for washboard lines in the middle wire cutting is that molybdenum wires don't walk up and down a line in the work area, and the difference between the two lines causes the amplitude of washboard unevenness. The mechanical reason is the root of washboard lines. The running track of guide wheel, bearing, conductive block and molybdenum wire is the main reason, and the advance or lag caused by uneven feed is also one of the reasons.

 

There is also a washboard pattern. Its periodic rule is not caused by molybdenum wire reversing, but by the periodic change of X and Y screw. It is the step where the screw pushes the carriage to move or the bearing carrying is not stable enough, resulting in the end face runout, or the screw gap is large, and there are foreign bodies, resulting in the end face runout. In short, as long as the cutting defect is caused by the periodic change of the screw, you should go to the screw to find the reason.