English Author: Site Editor Publish Time: 2025-12-23 Origin: Site
1. The axial positioning method of the main shaft was improperly selected
Error manifestation : the appropriate spindle axial positioning method (such as front-end configuration, rear-end configuration, two-end configuration or middle configuration) was not selected according to the processing requirements, resulting in the spindle extending due to heat, which affects the axial accuracy or bearing clearance.
The correct approach is : select the positioning method based on the processing accuracy and rigidity requirements. For instance, high-precision machine tools or CNC machine tools are recommended to adopt a front-end configuration , while ordinary precision machine tools can use a back-end configuration . Short spindles (such as combined machine tools) are suitable for configuration at both ends of , and configuration in the middle can reduce the overhang of the spindle.
Ⅱ. Ignore M code operations
Error representation : The M code (such as spindle on/off, coolant on/off, door open/closed, etc.) was not used correctly, resulting in the clamping system not meshing and the rotating shaft being subjected to unnecessary pressure.
Correct practice : Be familiar with and use the M code correctly to ensure that the clamping system meshes before processing and avoid damage to the rotating shaft.
Ⅲ.The method of setting the knife is unreasonable
Error manifestation : Unreasonable tool setting methods are adopted (such as the point operation tool setting method which takes a long time, the operation of the tool setting instrument is complex, and the positioning accuracy of the self-made tool setting block is poor), resulting in large processing errors or long preparation time.
The correct approach is : select the tool setting method according to the processing requirements. For instance, for simple processes, the point operation tool setting method can be adopted; for multi-tool measurement, the tool setting instrument method can be used; and for rapid positioning, the self-made tool setting block method can be selected (attention should be paid to positioning accuracy).
Ⅳ. Shape errors occur when processing spherical surfaces
Error manifestation : When processing spherical surfaces, problems such as protruding shoulders and scraping back occur due to improper adjustment. The main reasons are system clearance or uneven machining allowance of the workpiece.
The correct approach of is : control the gap error (0.01 to 0.02mm) by using the dial indicator measurement method , and ensure that the machining allowance of the workpiece is uniform to avoid "reflection" errors.
Ⅴ. Insufficient maintenance of the main shaft components
Error manifestation : Failure to clean the guide rails and replenish lubricating oil regularly leads to shortened service life of the spindle assembly or decreased processing accuracy.
The correct practice of is : regularly clean the guide rails, replenish lubricating oil, ensure that the service life of the main shaft assembly exceeds 8,000 hours, and pay attention to the clearance of the main shaft bearings (for example, the standard value of the C5112A vertical lathe is 0.04mm).
Ⅵ. Hydraulic System Failure
Error manifestations : The hydraulic pump is not operating properly, the pressure valve is malfunctioning, or the concentricity of the coupling is insufficient, resulting in severe noise and pressure fluctuations.
The correct practice of is : regularly inspect the hydraulic system, remove impurities from the pump, replace needle roller bearings, adjust the concentricity of couplings, and ensure that the oil level is sufficient and the suction position is reasonable.
Ⅶ. Compressed air contains moisture
Error manifestation : The compressed air contains moisture, causing rust and moisture to adhere to the taper hole of the main shaft and the tool holder, resulting in poor contact.
The correct practice of is : use an air dryer to process the compressed air and ensure it is dry before performing the blowing operation.
Ⅷ. Ignore the clearance of the equipment transmission pair
Error manifestation : The gap between the lead screw and the nut was not compensated, resulting in a raised shoulder on the machined surface during reverse movement.
The correct approach of is : use the dial indicator measurement method to control the clearance error (0.01 to 0.02mm), and perform reverse clearance compensation.
Ⅸ. The cutting parameters were not adjusted according to the material
Error manifestation : The cutting speed and feed rate were not adjusted according to the material (such as 45# steel, aluminum alloy), resulting in low processing efficiency or rapid tool wear.
The correct approach of is : adjust the cutting parameters according to the material properties. For example, the parameters for rough machining and finish machining should be set separately, and keep the spindle synchronized.
X. Failure to regularly inspect the clearance of the main shaft bearings
Error manifestation : The clearance of the main shaft bearing was not checked regularly, resulting in excessive error in the roundness of the outer circle during precision turning.
Correct practice : Regularly check the main shaft bearing clearance (for example, the standard value for the C5112A vertical lathe is 0.04mm), and readjust it when it exceeds the tolerance.
XI. No dedicated fuel supply system was used
Error manifestation : The dedicated oil supply system for hydrostatic bearings was not used, resulting in unstable oil film pressure and affecting processing accuracy.
Correct approach : Use a dedicated oil supply system to ensure that the oil film pressure is independent of the spindle speed, thereby enhancing processing accuracy.
ⅩII. The thermal deformation of the main shaft was not paid attention to
error manifestation : The elongation direction of the main shaft after heating was not paid attention to, resulting in the axial accuracy being affected.
The correct approach of is : select the positioning method based on the direction of thermal deformation of the main shaft. For example, when the main shaft extends backward after being heated, the front end configuration can be adopted; When extended forward upon heating, the rear end configuration can be adopted.
ⅩIII. Failure to inspect the hydraulic system regularly
Error manifestation : Failure to regularly inspect the hydraulic system leads to malfunction of the pressure valve or insufficient concentricity of the coupling.
The correct practice of is : regularly inspect the hydraulic system, remove impurities from the pump, replace needle roller bearings, adjust the concentricity of couplings, and ensure that the oil level is sufficient and the suction position is reasonable.
ⅩIIII. Dry compressed air was not used
Error manifestation : Dry compressed air was not used, resulting in rust and moisture adhering to the spindle taper hole and tool holder, causing poor contact.
The correct practice of is : use an air dryer to process the compressed air and ensure it is dry before performing the blowing operation.
