The machining center with the spindle axis of the vertical machining center perpendicular to the worktable refers to the machining center that can be used to process complex parts such as plates, discs, molds and small shells. However, the consistency of workpiece size in batch processing of vertical machining center is very high, which is relatively difficult for human operation. Even if there is a certain error value, it is assumed that improper reference data setting or operation error will indirectly affect the poor machining accuracy of workpiece. What are the reasons for the poor accuracy of vertical machining center? Let's briefly understand:

Vertical machining center
1. High machining roughness of vertical machining center will be caused by high cutting speed, inappropriate cutting fluid, excessive wear of reamer, excessive main deflection angle of reamer or too large allowance.
Because there are many reasons causing high roughness, it is difficult to solve. We can reduce the cutting speed, select the cutting fluid with reference to the processing materials, reduce the reaming allowance, improve the position accuracy and quality of the bottom hole before reaming, increase the reaming allowance, increase the chip holding slot space, or use the reamer with edge inclination angle to make the chip removal smooth, replace the reamer regularly, and select the tool reasonably.
2. Because the guide sleeve of the vertical machining center is worn, or the low end of the guide sleeve is too far away from the workpiece, the length of the guide sleeve is short or the accuracy is poor, which leads to the poor accuracy of the reamed hole position.
The guide sleeve can be checked and replaced regularly, the guide sleeve can be lengthened, the fit accuracy of the clearance between the guide sleeve and the reamer can be strengthened, and the clearance of the main shaft bearing can be adjusted in time.
3. Loose spindle bearings, sand holes or air holes on the hole surface, or the reamer is too long and the rigidity cannot be reached, will cause the inner hole reamed by the vertical machining center to be out of round.
It can be solved by using rigid connection for installation of reamer, selecting qualified reamer, controlling hole position tolerance in pre-processing process, using reamer with unequal tooth pitch, selecting qualified blank, regularly adjusting spindle clearance, etc.
4. The cutting speed of the vertical machining center is too high, the feed rate is improper or the machining allowance is too large, or the hole diameter of the vertical machining center is gradually increased due to it.
It can be handled according to the actual situation. Appropriately reducing the outer diameter of the reamer, reducing the cutting speed, reducing the main deflection angle, selecting the cutting fluid with better cooling performance, adjusting or replacing the main shaft bearing or replacing the whole main shaft can effectively solve the problem of increasing the hole diameter.