How to solve the unstable turning accuracy of CNC lathes?

CNC lathes are mainly used for processing various precision parts, but sometimes there may be unstable machining accuracy. What is the reason for this? Based on experience, CNC lathe manufacturers have summarized 9 reasons and corresponding solutions, hoping to be helpful to everyone.

1, The driving phase light works normally, but the size of the processed workpiece varies.

Cause of failure: The CNC lathe drag plate ran at high speed for a long time, causing wear on the screw and bearings; When the tool holder is used for a long time, there is a deviation in the accuracy of repeated positioning; The drag plate can accurately return to the machining starting point every time, but the size of the workpiece still varies. This phenomenon is generally caused by the spindle. Due to the high-speed rotation of the spindle, the bearings are severely worn, resulting in changes in machining dimensions.

Method for CNC lathe manufacturer: Place the dial gauge against the bottom of the tool holder, and edit a fixed cycle program through the system to check the repeated positioning accuracy of the drag plate, adjust the screw clearance, and replace the bearing; Check the repeated positioning accuracy of the tool holder with a dial gauge, adjust the machinery or replace the tool holder; Use a dial gauge to check the accuracy of returning to the starting point of the program after processing. If possible, inspect the spindle and replace the bearings.

2, The workpiece has precise dimensions and poor surface smoothness.

Reason for failure: The blade is damaged and not sharp; CNC lathe generates resonance and unstable placement; The machine tool exhibits crawling phenomenon; Poor processing technology.

Solution for CNC lathe manufacturers: If the tool is not sharp after wear or damage, grind the tool again or choose a better tool to readjust the tool; Vibration or unstable placement of the machine tool, adjust the level, lay the foundation, and fix it steadily; Mechanical crawling is caused by severe wear and tear on the trailer guide rails, as well as wear or loosening of the screw and ball bearings. The machine tool should be maintained carefully, and the iron wire should be cleaned and lubricating oil should be added in a timely manner when commuting to and from work to reduce friction; Choose a coolant suitable for workpiece processing, and try to use a high spindle speed as much as possible while meeting the processing requirements of other processes.

3, The workpiece exhibits a phenomenon of large or small taper.

Reason for failure: The machine tool is not properly leveled, with one high and one low, causing unstable placement; When turning a long shaft, the required material is harder, and the cutting tool has a deeper cut, resulting in the phenomenon of giving way to the tool; The tailstock and spindle are not consistent.

Solution for CNC lathe manufacturers: Use a spirit level to adjust the levelness of the machine tool, lay a solid foundation, fix the CNC lathe, and improve its toughness; Choose a reasonable processing technology to avoid excessive tool force and adjust the tailstock.

4, The machining effect of circular arcs is not ideal, and the size of small and medium-sized CNC lathes is insufficient.

Cause of failure: Resonance caused by overlapping vibration frequencies; Processing technology; Unreasonable parameter settings; Excessive feed rate causes instability in arc machining; Instability caused by excessive or tight clearance between screws; The synchronous belt is worn.

Solution: Identify the components that generate resonance, change their frequency to avoid resonance; Consider the processing technology of the workpiece material and develop a reasonable program; For stepper motors, the machining rate F cannot be too high; Whether the machine tool is firmly installed, placed smoothly, whether the mop is worn, whether the mop is too tight, and whether there is any gap in the tool holder; Replace the synchronous belt.