Comprehensive Winter Maintenance Guide for Swiss-type Lathes from JSWAY CNC COMPANY

To ensure the continuous and stable operation of Swiss-type lathes during winter, systematic maintenance should be conducted from four key aspects: Environmental Control, the Machine Itself, Processing Materials & Cutting Fluid, and Standardized Operations.

I. Environmental Control: The Foundation (Top Priority)
Swiss-type lathes are highly sensitive to temperature. The ideal operating environment temperature is typically 20°C ± 2°C.

• Maintaining a Constant Workshop Temperature:

  • Pre-heating: Turn on workshop heating equipment (e.g., central air conditioning, heaters) 1-2 hours before formal operation to raise and stabilize the ambient temperature within the suitable range. Never start machining directly in a low-temperature environment.

  • Avoid Localized Overheating: Do not point heating equipment directly at the machine tool to prevent thermal deformation caused by uneven heating.

• Humidity Control:

  • Dry winter air can exacerbate static electricity issues, which may interfere with the CNC system or damage precision circuits.

  • It is recommended to use industrial humidifiers to maintain workshop humidity at around 50% - 65%, effectively preventing static electricity without causing equipment corrosion.

II. Machine Maintenance and Warm-up

• Adequate Machine Warm-up:

  • Core Step: This is the most critical and non-negotiable step in winter maintenance.

  • Correct Procedure: After powering on, do not immediately begin high-precision machining. First, run the CNC system, then start the spindle oil cooler and guideway lubrication system. Run the spindle at a low speed (e.g., 500-1000 RPM) with no load, while simultaneously moving all axes (X, Y, Z) through slow, long-stroke reciprocating motions.

  • Duration: This process should last at least 15-30 minutes, longer if the initial workshop temperature is very low. The goal is to uniformly heat core components like spindle bearings, ball screws, and guideways to reach thermal equilibrium, eliminating internal clearances and restoring machining accuracy.

• Lubrication System Maintenance:

  • Check Oils: Verify that the guideway oil, spindle lubricating oil, hydraulic oil, etc., meet specifications and maintain good fluidity at low temperatures. Overly viscous oil can lead to poor lubrication and increased wear.

  • Central Lubrication: During the warm-up period, manually activate the central lubrication system multiple times to ensure all guideways and screws are fully lubricated before starting machining.

• Pneumatic System Protection:

  • Check the air compressor and dryer to ensure the dryness of the compressed air. Low winter temperatures can cause moisture in the air lines to freeze, blocking airflow and affecting tool changes, clamping, and other actions.

  • After each workday, open the drain valve at the bottom of the air receiver tank to discharge condensate.

III. Management of Processing Materials and Cutting Fluid

• Material "Acclimation Period":

  • Metal materials (e.g., bar stock) brought in from outdoors are extremely cold. Immediate machining can lead to dimensional instability due to cold contraction, and a "thermal shock" between the cold material and room-temperature cutting fluid/tools, affecting加工 quality and tool life.

  • Correct Practice: Bring materials into the workshop in advance and let them sit for 8-12 hours or more to reach the ambient workshop temperature.

• Cutting Fluid Freeze Prevention and Maintenance:

  • Prevent Freezing: Ensure the workshop temperature remains above 0°C to prevent cutting fluid from freezing in the machine tank and pipelines, which can burst pipes and damage pumps.

  • Concentration Management: Dry winter air causes faster water evaporation, potentially increasing the cutting fluid concentration. Regularly check the concentration and top up with pre-mixed dilution as needed, not just water.

  • Regular Circulation: If the machine is idle for extended periods (e.g., holidays), periodically start the cutting fluid pump to circulate the fluid through the lines and internal chambers, preventing sedimentation and bacterial growth.

IV. Standardized Operations and Daily Checks

• Establish Winter Operating Procedures:

  • Incorporate requirements like "pre-heating the workshop," "equipment warm-up procedure," and "material acclimation requirement" into the company's Standard Operating Procedures (SOP) and ensure strict adherence by operators.

• Enhanced Daily Checks:

  • Before Startup: Check air pressure, lubricant levels, and cutting fluid level/color.

  • During Operation: Listen for unusual noises from the spindle and ball screws; monitor the stability of machining dimensions to promptly detect accuracy drift caused by temperature changes.

  • After Shutdown: Clean chips from the machine tool promptly to prevent corrosion from condensed cutting fluid on chips. Moving all axes to the middle of their travel range helps maintain the machine's geometric accuracy.

Summary Checklist:

• Environment: Maintain a constant workshop temperature around 20°C and humidity at 50%-65%.

• Startup: Mandatory 15-30 minute no-load warm-up (low-speed operation of spindle and axes).

• Materials: Allow bar stock to acclimatize in the workshop sufficiently to match the ambient temperature.

• Fluids: Monitor cutting fluid concentration, prevent freezing, and ensure regular circulation.

• Air Source: Ensure dry compressed air; drain tanks daily.

• Procedures: Develop and strictly enforce winter SOPs; enhance daily checks.

Following these measures will minimize the impact of harsh winter conditions on your Swiss-type lathes, ensuring high-precision, efficient, and stable operation throughout the winter, reducing failure rates, and extending equipment service life.