Brushed Micromotor Commutator Polishing Film

Brushed Micromotor Commutator Polishing Film

Key Features and Benefits of Aluminum Oxide Lapping Film for Commutator Polishing:

1. Abrasive Material – Aluminum Oxide:

   • Durability & Efficiency: Aluminum oxide is a durable abrasive, ideal for creating a smooth, fine finish without excessive wear on the workpiece. It is particularly effective for polishing metals like copper, which is common in commutators.
   • Cost-Effectiveness: Compared to diamond abrasives, aluminum oxide is generally more affordable, offering a great balance between cost and performance.

2. Grit Range (600 to 4000 grit):

   • Wide Grit Spectrum: The grit range from 600 to 4000 grit allows for flexibility throughout the polishing process. Coarser grits (600–1000 grit) are typically used for initial grinding to remove heavy imperfections, while finer grits (2000–4000 grit) refine the surface to achieve a smooth, mirror-like finish.
   • Progressive Finishing: Starting with coarser grits and working your way to finer ones ensures better surface preparation, leading to reduced roughness and a better final finish.

3. Micron Range (3µm to 30µm):

   • The micron sizes (3µm to 30µm) correspond to the level of abrasiveness and precision achievable with the film. Lower micron sizes (e.g., 3µm–10µm) provide extremely fine finishes, while higher micron sizes (15µm–30µm) are more suited for rougher or more aggressive polishing stages.
   • The micron sizes ensure that even the smallest surface imperfections are removed, achieving the desired smoothness, which is crucial for the efficient operation of micromotors.

4. Precision and Surface Quality:

   • These polishing films are known for their high precision and repeatability, which ensures uniform surface finish across multiple parts. This is particularly important in industries where consistent motor performance is critical.
   • The films can help improve electrical contact and reduce wear on brushes, extending the motor's lifespan.

Applications:

• Commutator Polishing: Aluminum oxide lapping films are perfect for micromotor commutators, whether they’re used in power tools, automotive parts, or small appliances.
• Motor Maintenance: Polishing the commutator with this film reduces the likelihood of issues like electrical arcing, which can affect motor performance and efficiency.

Advantages for Micromotor Commutators:

• Smooth and Durable Finish: With aluminum oxide's durability, it ensures the commutator retains a smooth and consistent finish after polishing, which is vital for long-term performance.
• Cost-Effective Solution: Aluminum oxide is more affordable than some other abrasives like diamond, making it a practical choice for industries requiring high-volume polishing.

When choosing the right polishing film grit or micron size for micromotor commutator polishing, and using only one grit for the entire process, it's important to consider several factors that will help determine the best choice for your specific application. Let's explore each factor to help you choose the right micron size for optimal performance.

Typical Grit Options:

• 3μm (4000#): Fine grit, for final polishing and achieving a smooth, mirror-like finish.
• 12μm (1700#): Medium-fine grit, for refining the surface without removing too much material.
• 20μm (800#): Medium grit, for surface smoothing and moderate material removal.
• 30μm (600#): Coarse grit, for heavier material removal and smoothing of rough surfaces.

Factors to Consider When Choosing the Polishing Film Grit:

1. Condition of the Commutator:

• Heavily Worn or Rough Commutators:

  • If the commutator is damaged, has deep scratches, pits, or heavy wear, you'll need to start with a coarser grit (like 30μm, 600#) to effectively remove material and smooth out imperfections.
  • Recommended Grit: 30μm (600#) would be ideal for heavy stock removal, as it can tackle rough surfaces efficiently.

• Slightly Worn or Moderately Damaged Commutators:

  • If the commutator shows only light wear or shallow scratches, a medium grit (like 20μm, 800#) is a good choice to smooth out imperfections without over-polishing or excessive material removal.
  • Recommended Grit: 20μm (800#) is a suitable choice to smooth and refine the surface without the need for heavy removal.

• Lightly Scratched or Polished Commutators:

  • For commutators with minor surface imperfections or those requiring a smooth, shiny finish, a fine grit (like 12μm, 1700# or 3μm, 4000#) will be better, providing a polished and smooth surface.
  • Recommended Grit: 12μm (1700#) or 3μm (4000#) depending on how smooth you need the finish to be.

2. Desired Finish Quality:

• High-Quality Mirror Finish:

  • If your goal is to achieve the smoothest possible finish with minimal surface roughness, choose 3μm (4000#). This grit will deliver a fine, polished surface that reduces roughness and enhances electrical contact, ideal for high-performance motors.
  • Recommended Grit: 3μm (4000#) provides the finest finish for a mirror-like appearance.

• Moderate Surface Refinement:

  • If you only need a moderately smooth finish and are working with a commutator that isn't heavily damaged, 12μm (1700#) will provide a good balance between material removal and surface refinement.
  • Recommended Grit: 12μm (1700#) is suitable for refining the surface and giving a polished look without over-polishing.

• Standard Polishing (Good Performance, Not Mirror-Like):

  • If you're looking for a standard polishing result without aiming for a mirror finish, 20μm (800#) or 30μm (600#) will provide good results for general performance without over-polishing.
  • Recommended Grit: 20μm (800#) or 30μm (600#) for practical polishing.

3. Motor Type and Application:

• High-Performance Motors (Sensitive Applications):
  • For motors that require extremely smooth, high-precision commutators (e.g., motors in sensitive or high-speed applications), the 3μm (4000#) grit will be most beneficial, providing the smoothest finish and reducing electrical contact resistance.
  • Recommended Grit: 3μm (4000#) for high-precision and sensitive motor applications.
• Standard or General Motors:
  • For standard motors where a less aggressive and finer finish is sufficient, 12μm (1700#) or 20μm (800#) grit films can give good results without needing an ultra-fine finish.
  • Recommended Grit: 12μm (1700#) or 20μm (800#) for standard applications.

4. Film Durability and Consistency:

• When choosing a polishing film, the abrasive consistency and durability are crucial for maintaining a uniform finish. The film should hold up during the polishing process and provide consistent abrasiveness.
  • Higher Micron (Coarse Grains): Grits like 30μm (600#) and 20μm (800#) are more durable in terms of handling larger areas and more aggressive material removal.
  • Lower Micron (Fine Grains): Grits like 12μm (1700#) and 3μm (4000#) are softer but provide a higher-quality finish, especially for finishing work.

5. Efficiency and Speed of Polishing:

• If you need faster polishing and material removal, coarse grits like 30μm (600#) or 20μm (800#) will help you achieve a faster result.
• If you're polishing for a finer finish and slower, controlled polishing is acceptable, 12μm (1700#) and 3μm (4000#) will provide better results with finer abrasives for a smooth, uniform surface.

Recommended Grit Selection Based on Factors:

• Heavily Worn or Damaged Commutator:

  • Recommended Grit: 30μm (600#) (Coarse grit for material removal and surface smoothing)

• Moderately Worn or Lightly Scratched Commutator:

  • Recommended Grit: 20μm (800#) or 12μm (1700#) (Medium grit for surface refinement)

• Smooth/Polished Commutator:

  • Recommended Grit: 12μm (1700#) or 3μm (4000#) (Fine grit for a high-quality, smooth finish)

• High-Performance Motor with Precision Requirements:

  • Recommended Grit: 3μm (4000#) (Finest finish for high-performance, mirror-like results)

Summary of Polishing Grit Selection:

• 3μm (4000#): Use for mobile phone or mini micro motor polishing and achieving a mirror-like, smooth finish. Best for high-precision motors. for Hollow Cup Motor / Coreless Motor
• 12μm (1700#): Use for general refinement of moderately worn commutators or when a standard finish is required. for Hollow Cup Motor / Coreless Motor
• 20μm (800#): Use for moderate surface smoothing and standard commutator polishing.  for Iron core motor
• 30μm (600#): Use for heavy stock removal on heavily worn commutators or when aggressive material removal is necessary. for Iron core motor.

Commutator Material: The material of the commutator, typically copper or a copper alloy/Brass，Bakelite, dictates the selection of the abrasive.

Copper Commutator: Use 30μm (600#) 

Copper Alloy or Brass Commutator: Use 20μm (800#) 

Ag-Pd Alloy Commutator: Use 12μm (1700#) 

Silver (plated or coated with silver) Commutator: Use 3μm (4000#) 

Conclusion:

• If you're only using one grit for polishing the commutator, the most important considerations are the condition of the commutator and the desired finish quality.
• For heavily worn commutators, start with 30μm (600#), while for lighter scratches or surface wear, use 12μm (1700#) or 20μm (800#).
• For mirror finishes and high-performance motors, 3μm (4000#) is your best choice, offering the smoothest, most refined finish.