Here is a comprehensive professional installation guide for THK LM Linear Motion Guides, synthesized from manufacturer specifications and technical documentation. Key steps and precautions are prioritized for precision and operational safety.

1. Pre-Installation Preparation 

• Surface Cleaning:
  Remove burrs, dents, and contaminants from the mounting surface. Residual debris compromises alignment and load distribution.

• Degreasing:
  Wipe off THK's factory-applied anti-rust oil using a solvent (e.g., kerosene or specialized cleaner), then apply a low-viscosity lubricant (e.g., spindle oil) to prevent rust.

• Tool Check:
  Ensure torque wrenches, dial gauges, and alignment tools are calibrated. Avoid improvised tools.

2. Rail Installation Procedure 

Step 1: Reference Rail Placement

• Gently position the reference rail (marked "HIWIN" or "THK") on the base.

• Temporary Bolting: Loosely tighten bolts at both ends (≈30% final torque) to allow micro-adjustments.

Step 2: Alignment & Parallelism

• Use a dial gauge to measure flatness (≤0.02 mm/m). Shim gaps exceeding 0.05 mm.

• For paired rails, align the secondary rail using precision spacers or step gauges to ensure parallelism (tolerance: ±0.01 mm).

Step 3: Bolt Tightening Sequence

Follow a cross-pattern tightening sequence to avoid stress concentration:

3. Carriage Block Handling 

• Avoid Disassembly:
  Do not detach blocks from rails unless necessary. Forced separation risks ball retention issues.

• Mounting Blocks:
  Slide blocks onto rails and align with mounting holes. For flange types, secure bolts diagonally to prevent tilting.

• Auto-Alignment Feature (HR-Type):
  Utilize the arc-groove design to absorb ±0.3° angular misalignment during preload application.

4. Lubrication & Sealing 

• Grease Selection:
  Use THK-recommended lithium-soap-based grease for standard applications. For high-speed/loads, opt for synthetic oils.

• Lubrication Volume:
  Fill 30–50% of block cavity. Overfilling causes overheating; underfriction leads to wear.

• Seal Maintenance:
  Inspect wipers and seals for debris. Replace damaged seals immediately to prevent contamination.

5. Post-Installation Validation 

• Manual Testing:
  Slide blocks by hand to detect stiffness or uneven motion. Resistance indicates misalignment or over-torquing.

• Preload Check:
  Verify preload via force gauges. Excess preload accelerates wear; insufficient preload causes play.

• Run-Test:
  Operate at 10% max speed initially, then incrementally increase while monitoring noise/vibration.

Critical Precautions 

1. Never strike rails/blocks with hammers. Use soft mallets for adjustments.

2. Avoid welding near rails – heat distortion compromises flatness.

3. Support long rails at intermediate points (e.g., LM support units) to prevent sagging .

4. Dust Protection: Install THK’s QZ self-lubricators or seals in contaminated environments .

Troubleshooting Common Issues 

• Uneven Wear: Recheck rail parallelism and bolt torque.

• Abnormal Noise: Inspect lubrication levels or ball recirculation paths.

• Stiff Movement: Verify seal contact and contamination ingress.

For detailed torque specs or model-specific guidelines, consult THK’s technical manuals.