When the water jet cutter is cutting, according to the numerical control instruction, the cutting path is the theoretical size, but the actual cutting size will have a little deviation. This is because there is a slit in the cutting process, and the cutting seam is the part of the loss during cutting. Therefore, if the geometric dimension compensation is not carried out, The length direction of the outer contour part of the actual cutting part will be smaller, and the inner contour size will be larger (the gap width between two sides is just different from that of the single side).
For example, if we want to cut a circular workpiece with a diameter of φ 100 mm and a water beam diameter of 1m, then the cutting track of the water jet cutter will be cut according to a circular path with a diameter of φ 101mm (the cutting motion track is the track of the cutting water beam center, and the motion coordinates indicated by the G code generated in the CAD/CAM software are the coordinates of the cutting motion track), rather than the circle of φ 100mm. If the trajectory is φ 100mm, the diameter of the final cut workpiece is only φ 99mm, and the radius of the cutting water beam is smaller than the required diameter of φ 100mm. In order to compensate for the missing cutting radius, in CAD/CAM software, it is necessary to add a cutting radius (if it is a cutting hole, a cutting radius should be subtracted) on the basis of the workpiece size in the CAD/CAM software, which is called radius compensation, so as to finally process the workpiece with the required size.
The following points should be paid attention to when setting the slotting compensation:
1. After the software compensation is set, it is generally not necessary to compensate on the CNC system, otherwise, the compensation repeated size will appear deviation, but if the software compensation is a little worse after cutting, it can be compensated through the CNC system.
2. If it is compensated by the CNC system, the compensation value should be set to zero in the software.
3. If you are not sure how much size should be compensated, you can cut a rectangle on the scrap, measure the actual size and the programmed size, and calculate the required compensation amount.
4. It is difficult for the CNC system to deal with the compensation of small arcs. If the arc is smaller than the compensation radius, it can not be cut out, nor can it be compensated correctly (in theory, the radius becomes negative). In this case, we should consider modifying the part drawing or using software compensation to find problems in time.